diff --git "a/x-biology-em(csv).csv" "b/x-biology-em(csv).csv" new file mode 100644--- /dev/null +++ "b/x-biology-em(csv).csv" @@ -0,0 +1,16854 @@ +"SC" +"ER" +"T" +"TE" +"LA" +"NG" +"AN" +"A" +" SC" +"ER" +"T" +"TE" +"LA" +"NG" +"AN" +"A" +" BIOLOGY" +"" +"" +"" +"" +"A" +"CLASS - 10" +"" +"" +"" +"" +"AN" +"Editors" +"" +"" +"" +"" +"NG" +"Dr. Kamal Mahendroo, Professor, Kaneria Professor," +"Dr. Yashodhara Kaneria," +"Vidya Bhavan Educational Resource Centre, Vidya Bhavan Educational Resource Centre," +"Udaipur, Rajastan. Udaipur, Rajastan." +"" +"Dr. Snigdha Das, Professor, Dr. A. Nagamani, Professor," +"LA" +"Vidya Bhavan Educational Resource Centre, University College of Science," +"Udaipur, Rajastan. Saifabad., Hyderabad." +"" +"Dr. Nannuru Upendar Reddy" +"Reddy," +"Professor & Head C&T Dept.," +"TE" +"" +"SCERT., Hyderabad." +"" +"" +"" +"Co-ordinator" +"" +"Dr. T.V.S. Ramesh," +"T" +"" +"" +"" +"Co-ordinator, C&T Dept.," +"SCERT, Hyderabad." +"ER" +"SC" +"" +"" +"" +"" +"Published by the Government of Telangana, Hyderabad." +"" +"Respect the Law Grow by Education" +"Get the Rights Behave Humbly" +"" +"" +"Free distribution by T.S. Government 2019-20 i" +" A" +"AN" +"© Government of Telangana, Hyderabad." +"" +"First Published 2014" +"New Impression 2015, 2016, 2017, 2018, 2019" +"" +"" +"" +"" +"NG" +"All rights reserved." +"" +"No part of this publication may be reproduced, stored" +"in a retrieval system, or transmitted, in any form or by" +"any means without the prior permission in writing of the" +"LA" +"publisher, nor be otherwise circulated in any form of" +"binding or cover other than that in which it is published" +"and without a similar condition including this condition" +"being imposed on the subsequent purchaser." +"The copy right holder of this book is the Director" +"TE" +"" +"of School Education, Hyderabad, Telangana." +"We have used some photographs which are under" +"creative common licence. They are acknowledged" +"at the end of the book." +"" +"This Book has been printed on 70 G.S.M. S.S. Map litho," +"T" +"" +"" +"" +"Title Page 200 G.S.M. White Art Card" +"ER" +"" +"" +"" +"" +"Free Distribution by Government of Telangana 2019-20" +"SC" +"" +"" +"" +"" +"Printed in India" +"at the Telangana Govt. Text Book Press," +"Mint Compound, Hyderabad," +"Telangana." +"" +"" +"" +"ii" +" A" +"Text Book Development Committee" +"" +"" +"" +"" +"AN" +"Sri G. Gopal Reddy, Director, Sri B. Sudhakar,, Director," +"S.C.E.R.T., Hyderabad. Govt. Textbook Press, Hyderabad." +"" +"Dr. Nannuru Upendar Reddy," +"Professor & Head C&T Dept.," +"" +"" +"" +"" +"NG" +"S.C.E.R.T., Hyderabad." +"" +"" +"" +"Writers" +"" +"Dr. T.V.S. Ramesh, Co-ordinator," +"LA Sri Ch. Keshava Rao, Lecturer," +"C&T Dept.,SCERT, Hyderabad. DIET Hanamkonda, Warangal." +"" +"Sri Vinjanampati Raghava Rao, Lecturer, Sri Pramod Kumar Padhy, SA," +"APRJC Sarvail, Nalgonda. ZPHS B.R.C Puram, Srikakulam." +"TE" +"" +"Dr. S. Vishnuvardhan Reddy, SA, Sri Sk. Taj Babu, SA," +"ZPHS Kadtal, Mahaboobnagar. ZPHS Chilkur, Rangareddy." +"" +"Sri Sanjeev Kumar, SA, Sri Meda Hari Prasad, SA," +"ZPHS Amdapur, Nizamabad. ZPHS Akumalla, Kurnool." +"T" +"" +"" +"" +"Sri Noel Joseph, HM," +"HM, Smt K. Uma Rani, SA," +"St. Joseph’s High School, GHS Ameerpet-1," +"ER" +"" +"" +"" +"" +"Ramagundam, Karimnagar. Jawaharnagar, Hyderabad." +"Sri E.D. Madhusudhan Reddy, SA, Sri Banala Jayaraju, SA," +"ZPHS Boys, Kosgi, ZPHS Choutuppal," +"Mahbubnagar Dist. Nalgonda Dist." +"SC" +"" +"" +"" +"" +"Cover page, Graphics & Designing" +"" +"Sri K. Sudhakara Chary, SGT, Sri Kishan Thatoju, Graphic Designer," +"UPS Neelikurthy, Warangal. C&T Dept.,SCERT, Hyderabad." +"Sri Mohd. Ayyub Ahmed, S.A., Sri Kannaiah Dara, DPO& Graphic Designer," +"Z.P.H.S. U/M, Atmakur, Mahbubnagar. C&T Dept.,SCERT, Hyderabad." +"Free distribution by T.S. Government 2019-20 iii" +" Intro ..." +"" +"" +"" +"" +"A" +"We believe that class-10 education is a key aspect of school education and a" +"" +"" +"" +"" +"AN" +"turning point in student’s life. The present tenth class Science textbook in your" +"hands is developed in accordance with the National and State Curriculum Framework" +"and the Right to Education Act. This book helps the student to review various" +"concepts that were learned through the learning experiences provided in the school" +"and to get comprehensive knowledge about these conecepts. The lessons in the" +"textbooks are presented in such way that they help in preparing the student for" +"" +"" +"" +"" +"NG" +"competitive examinations and also to prepare him/her for intermediate education." +"The new science textbooks are specially designed with suitable pedagogy in" +"tune with Continuous Comprehensive Evaluation (CCE) which we are right now" +"implementing in school education. These textbooks help the teacher to assess" +"students learning during teaching learning processes. They facilitate effective learning" +"of various concepts of science in scientific method apart from getting knowledge" +"LA" +"about concepts. It is essential to complete the syllabus in the stipulated time as" +"students have to write the Board Examination in class-10. But don’t forget that" +"completion of syllabus means making the students understand the concepts and" +"trying to achieve the learning competencies. It is mandatory on the part of teacher" +"to implement teaching strategies like, making the student to read the content of" +"TE" +"" +"the textbook, discussion, analysis, lab activity, field trips, preparing reports, etc." +"Teacher must take special care to avoid the practice of rote memorisation of" +"scientific information from guides and question banks." +"The classroom teaching of science must be in such a way that it encourages" +"children to think and work scientifically. Also, it must enhance love towards nature." +"Even it should enable to comprehend and appreciate the laws governing the nature" +"T" +"" +"" +"in constructing so much diversity all around. Scientific learning is not just disclosing" +"new things. It is also necessary to step forward without interrupting the" +"interrelationship and interdependency along with understanding of the nature’s" +"ER" +"" +"" +"" +"" +"intrinsic principles.High School children possess cognitive capacity of comprehending" +"the nature and characteristics of the transforming world surrounding them. And" +"they are able to analyze abstract concepts." +"At this level, we cannot quench their sharp thinking capability with the dryteaching" +"of mere equations and theoretic principles. For that, we should create a learning" +"environment in the classroom which provides an opportunity for them to apply the" +"SC" +"" +"" +"" +"" +"scientific knowledge, explore multiple alternatives in solving problems and establish" +"new relations." +"Scientific learning is not just confined to the four walls of classroom. It has a" +"definite connection to lab and field as well. Therefore, there is a lot of importance" +"to field experience/ experiments in science teaching." +"" +"" +"" +"" +"iv" +" There is a great need for compulsory implementation of instructions of the" +"" +"" +"" +"" +"A" +"National Curriculum Framework- 2005 which emphasizes linking of the science teaching" +"with local environment. The Right to Education Act- 2009 also suggested that" +"priority should be given to the achievement of learning competencies among children." +"" +"" +"" +"" +"AN" +"Likewise, science teaching should be in such a way that it would help cultivate a" +"new generation with scientific thinking." +"The key aspect of science teaching is to make the children understand the" +"thinking process of scientists and their efforts behind each discovery. The State" +"Curriculum Framework- 2011 stated thatchildren should be able to express their" +"own ideas and opinions on various aspects. These Science Text Books are prepared" +"" +"" +"" +"" +"NG" +"to meet the set standards of the SCF and thus assist children in becoming self-" +"reliant researchers capable of thinking intensely in scientific terms." +"The new textbooks are developed to achieve desired academic standards. So" +"teachers should develop various teaching learning strategies to make their students" +"to achieve class specific academic standards. We should avoid rote learning methods" +"for the successful implementation of Continuous Comprehensive Evaluation (CCE)." +"LA" +"It is very impart to know more about different methods to assess students’" +"progress by summative and formative evaluation. The new textbooks reflect" +"Continuous Comprehensive Evaluation and teaching method with respect to discussed" +"concepts. This is very useful to teachers and students." +"In the new textbooks, the design of concepts and activities help in achieving" +"TE" +"" +"the specified academic standards. Teachers need to plan appropriate teaching" +"strategies to improve the academic standards among the students by the end of" +"teaching the lesson. For effective implementation of continuous comprehensive" +"evaluation the teaching must move away from the methods of rote memorisation" +"of concepts. There is a need for teachers to have a good understanding of the" +"methods of evaluation which help them in assessing the progress of children in a" +"constructive and comprehensive way. The new textbooks are not confined to" +"T" +"" +"" +"simply provide necessary informations about concepts. Instead they focus on the" +"new teaching strategies and evaluation techniques which are very important for" +"both teachers and students." +"ER" +"" +"" +"" +"" +"We thank the VidyaBhavan Society, Rajasthan for their cooperation in designing" +"these new text books,the writers for preparing the lessons, Smt. Pulipati Parameswari" +"who helps in translation, the editors for checking the textual matters and the DTP" +"group for cutely composing the textbook. We invite suggestions from educationists," +"teachers, parents, students and others to make this book more meaningful." +"SC" +"" +"" +"" +"" +"Teachers play a pivotal role in children’s comprehensive use of the text book." +"We hope, teachers will make their best efforts for proper utilization of the text book" +"so as to inculcate scientific thinking among children and inspire them to be great" +"scientists." +"Director," +"SCERT, Hyderabad" +"" +"" +"" +"" +"Free distribution by T.S. Government 2019-20 v" +" Dear teachers..." +"" +"" +"" +"" +"A" +"New Science Text Books are prepared in such a way that they develop children’s observation" +"power and research enthusiasm. The official documents of national and State Curriculum frame" +"" +"" +"" +"" +"AN" +"works and the Right Education Act are aspairing to bring grossroute changes in science teaching." +"These textbooks are adopted in accordance with such an aspiration. Hence, science teachers" +"need to adapt to the new approach in their teaching." +"In view of this, let us observe certain Dos and Don’ts:" +"• There is an immediate need to discard the practices adopted in the schools on a false belief" +"that teaching of 10th class means preparing the children for public examination. In 10th" +"" +"" +"" +"" +"NG" +"class the teaching learning process should focus on achieving the academic standards rather" +"winning race of scoring marks." +"• Avoid practices like using guides and question banks, asking the children to read only" +"important questions, focussing on lessons which help in scoring more marks." +"• Read the lesson thoroughly before you start teaching and ask the children to read the text." +"LA" +"Then initiate a discussion to make the children understand the concepts in the lessons." +"• Encourage children to express their own views and ideas while writing the answers. Give" +"weightage to such type of writing in examination." +"• Some instructions are given in the textbook regarding the collection of certain information" +"by the teacher. Collect such information and make it available to students." +"TE" +"" +"• In public examination, the weightage will be given to all aspects of the syllabus. Except" +"foreword of the textbook everything else must be treated as a part of the curriculum." +"• Textual concepts are presented in two ways: one as the classroom teaching and the other" +"as the laboratory performance." +"• Lab activities are part and parcel of a lesson. So, teachers must make the children conduct" +"all such activities during the lesson itself, but not separately." +"T" +"" +"" +"" +"• Teachers are advised to follow the following teaching steps while transacting lessons-mind" +"mapping, reading lesson and identifyng new words by children, performing activities," +"ER" +"" +"" +"" +"" +"demonstration and discussion, conclusion and evaluation." +"• In the text, some special activities are presented as box items: ‘think and discuss, let us do," +"conduct interview, prepare report, display in wall magazine, participate in Theatre Day, do" +"field observation, organize special days’. To perform all of them is compulsory." +"• The abbreviation (A.S.) given at the end of each question in the section “Improve your" +"SC" +"" +"" +"" +"" +"learning” indicates academic standard." +"• Collect information of relevant website addresses and pass on to students so that they can" +"utilize internet services for learning science on their own." +"• Plan and execute activities like science club, elocution, drawing, writing poetry on science," +"making models etc.to develop positive attitude among children about environment," +"biodiversity, ecological balance etc." +"" +"" +"" +"vi" +" • As a part of continuous comprehensive evaluation, observe and record children’s" +"learning abilities during various activities conducted in classroom, laboratory and field." +"• Teaching learning strategies and the expected learning outcomes, have been developed" +"" +"" +"" +"" +"A" +"class wise and subject-wise based on the syllabus and compiled in the form of a" +"Hand book to guide the teachers and were supplied to all the schools. With the help of" +"" +"" +"" +"" +"AN" +"this Hand book the teachers are expected to conduct effective teaching learning" +"processes and ensure that all the students attain the expected learning outcomes." +"We believe, you must have realized that the learning of science and scientific thinking" +"are not mere drilling of the lessons but, in fact, a valuable exercise in motivating the" +"children to explore for solutions to the problems systematically and preparing them to" +"meet life’s challenges properly." +"" +"" +"" +"" +"NG" +"Dear Students..." +"Learning science does not mean scoring good marks in the subject. Competencies" +"like thinking logically and working systematically, learned through it,have to be practiced" +"in daily life. To achieve this, instead of memorizing the scientific theories by rote, one" +"must be able to study them analytically. That means, in order to understand the concepts" +"of science, you need to proceed by discussing, describing, conducting experiments to" +"verify, making observations, confirming with your own ideas and drawing conclusions." +"LA" +"This textbook helps you to learn in that way." +"What you need to do to achieve such things:" +"• In 10th class the range of concepts is wide. So go through each lesson thoroughly" +"before the teacher actually deals with it." +"• Note down the points you came across so that you can grasp the lesson better." +"TE" +"" +"• Think of the principles in the lesson. Identify the concepts you need to know further," +"to understand the lesson in depth." +"• Do not hesitate to discuss analytically about the questions given under the sub-heading" +"‘Think and Discuss’ with your friends or teachers." +"• You may get some doubts while conducting an experiment or discussing about a" +"lesson. Express them freely and clearly." +"T" +"" +"" +"• Plan to implement experiment/lab periods together with teachers, to understand the" +"concepts clearly. While learning through the experiments you may come to know" +"many more things." +"ER" +"" +"" +"" +"" +"• Observe how each lesson is helpful to conserve nature. Put what you learnt into practice." +"• Analyse how each teaching point has relation with daily life and discuss the things" +"you learned in your science class with farmers, artisans etc." +"• Work as a group during interviews and field trips. Preparing reports and displaying" +"them is a must. Discuss on the report prepared." +"• List out the observations regarding each lesson to be carried through internet, school" +"SC" +"" +"" +"" +"" +"library and laboratory." +"• Whether in note book or exams, write analytically, expressing your own opinions." +"• Read books related to your text book, as many as you can." +"• You organize yourself the Science Club programs in your school." +"• Observe problems faced by the people in your locality and find out what solutions" +"you can suggest through your science classroom." +"" +"" +"Free distribution by T.S. Government 2019-20 vii" +" ACADEMIC STANDARDS" +"" +"" +"" +"" +"A" +"S.No. Academic Standard Explanation" +"" +"" +"" +"" +"AN" +"1. Conceptual understanding Children are able to explain, cite examples, give reasons," +"and give comparison and differences, explain the process" +"of given concepts in the textbook. Children are able to" +"develop their own brain mappings." +"" +"" +"" +"" +"NG" +"2. Asking questions and making Children are able to ask questions to understand, to" +"hypothesis clarify the concepts and to participate in discussions." +"They are able to make hypothesis on experimental results" +"and given issues." +"" +"3. Experimentation and field To understand given concepts in the textbook children" +"investigation." +"LA" +"are able to do experiments on their own. They are able" +"to arrange the experimental materials, note their" +"observations, collect alternate expermental materials," +"take precautions, participate in field investigation and" +"making reports on them." +"TE" +"" +"4. Information skills and Children are able to collect information (by using" +"Projects interviews, checklist, questionaire) and analyses" +"systematically. They are able to conduct their own" +"project works." +"T" +"" +"" +"5. Communication through Children are able to explain their conceptual" +"drawing, model making understanding by drawing figures labelling, describe the" +"parts and making models. Able to ploting graphs by using" +"ER" +"" +"" +"" +"" +"given information or collected data." +"" +"" +"6. Appreciation and aesthetic Children are able to appreciate man power and nature," +"sense, values and have aesthetic sense towards nature. They are also" +"able to follow constitutional values." +"SC" +"" +"" +"" +"" +"7. Application to daily life, Children are able to utilize scientific concept to face" +"concern to bio diversity. their daily life situations. They are able to show concern" +"towards bio diversity." +"" +"" +"" +"" +"viii" +" A" +"INDEX" +"" +"" +"" +"" +"AN" +"Periods Month Page No." +"" +"" +"" +"" +"NG" +"Nutrition - Food Supplying system 10 June 1" +"" +"" +"Respiration - The energy releasing system" +"LA 10 July 24" +"" +"" +"Transportation - The circulatory system 10 August 48" +"" +"" +"Excretion - The wastage disposing system 10 September 74" +"TE" +"" +"Coordination - The linking system 10 October 94" +"" +"" +"Reproduction - The generating system" +"T" +"" +"" +"15 November 116" +"ER" +"" +"" +"" +"" +"10 November/ 144" +"Coordination in life processes December" +"" +"15 December/ 166" +"Heredity - From parent to progeny January" +"SC" +"" +"" +"" +"" +"Our environment - Our concern 10 January 193" +"" +"" +"" +"Natural resources 10 January 212" +"" +"Revision February" +"Free distribution by T.S. Government 2019-20 ix" +" OUR NATIONALANTHEM" +"" +"" +"" +"" +"A" +"- Rabindranath Tagore" +"" +"" +"" +"" +"AN" +"Jana gana mana adhinayaka Jaya he" +"Bharatha bhagya vidhata!" +"Punjab Sindh Gujaratha Maratha," +"" +"" +"" +"" +"NG" +"Dravida Utkala Banga!" +"" +"Vindhya Himachala Jamuna Ganga," +"Uchchala Jaladhi taranga!" +"Tava shubha name jage!" +"Tava shubha asisha mage!" +"LA" +"Gahe tava jaya gatha!" +"" +"Jana gana mangala dayaka jaya he!" +"Bharatha bhagya vidhatha!" +"TE" +"" +"Jaya he! jaya he! jaya he!" +"Jaya jaya jaya jaya he!" +"T" +"" +"" +"" +"PLEDGE" +"ER" +"" +"" +"" +"" +"- Pydimarri Venkata Subba Rao" +"" +"“India is my country; all Indians are my brothers and sisters." +"I love my country, and I am proud of its rich and varied heritage." +"SC" +"" +"" +"" +"" +"I shall always strive to be worthy of it." +"I shall give my parents, teachers and all elders respect," +"and treat everyone with courtesy. I shall be kind to animals." +"To my country and my people, I pledge my devotion." +"In their well-being and prosperity alone lies my happiness.”" +"" +"x" +" A" +"Chapter" +"" +"" +"" +"" +"AN" +"1" +"" +"" +"NG" +"Nutrition - Food supplying system" +"LA" +"Food is needed by all living organisms mainly for growth and repair." +"Several organisms need food to maintain body temperature as well. A" +"variety of substances are taken as food by every organisms from single" +"celluar organisms like amoeba to the complex multicellular organisms" +"like the human body. Even within the human body the cells require a wide" +"TE" +"" +"variety of substances as food to carryout their functions. The mode of" +"acquiring food varies from organism to organism." +"You have studied in the previous classes about how different organisms" +"get their food. Let us recall them." +"What are autotrophs? How do autotrophs get their food?" +"T" +"" +"" +"" +"What are heterotrophs? How do heterotrophs get their food?" +"Let us study about autotrophic and heterotrophic modes of nutrition" +"ER" +"" +"" +"" +"" +"and find out why most plants are called as autotrophs." +"Autotrophic Nutrition" +"We know that autotrophs are the organisms capable of using light" +"energy to synthesize chemical compounds. They acquire nutrients like" +"SC" +"" +"" +"" +"" +"mineral salts and water from the soil as well as some gases from the air." +"They are capable of producing complex compounds like carbohydrates," +"proteins and lipids from these very simple substances. These compounds" +"produced by autotrophic plants are utilized for providing energy to most" +"of the living organisms and all animals including human beings." +"Most of the food that we eat are obtained from plants. Even if we" +"depend on animal products, we would find that those animals depend on" +"Free distribution by T.S. Government 2019-20 1" +" plants for their food. But how do plants carry out their life processes?" +"Scientists have been working for centuries to find out how plants carry" +"out these life processes. We know that among all life processes, the process" +"" +"" +"" +"" +"A" +"of photosynthesis makes plants “the universal food providers” for all living" +"organisms." +"" +"" +"" +"" +"AN" +"You have studied something about photosynthesis in your earlier" +"classes. Von Helmont and other scientists believed that plants get their" +"food material not only from soil but also from other sources." +"Can you name some raw materials needed for photosynthesis?" +"What could be the end products of the process of photosynthesis?" +"" +"" +"" +"" +"NG" +"Let us study the process of photosynthesis in detail." +"Photosynthesis" +"" +"Photosynthesis is the process by which" +"plants containing the green pigment" +"LA" +"oxygen ‘chlorophyll’ build up complex organic" +"molecules from simple inorganic ones," +"using sun light as an energy source. The" +"sunlight" +"process of photosynthesis is very complex." +"TE" +"" +"Several reactions takes place in this process" +"carbon dioxide" +"chlorophyll and intermediate compounds are also" +"formed. Scientists had tried to formulate a" +"water simple equation to indicate photosynthesis" +"over 200 years. The equation that is used" +"T" +"" +"" +"fig-1: Photosynthesis widely is formulated and proposed by" +"C.B. Van Neil in 1931 . His opinion was," +"“for each molecule of carbohydrate formed, one molecule of water and" +"ER" +"" +"" +"" +"" +"one molecule of oxygen is produced”. Though photosynthesis is a very" +"complex process, we use the following simple equation." +"Light" +"CO2 + 2H2O CH2O + H2O + O2" +"Chlorophyll" +"SC" +"" +"" +"" +"" +"What would be the reaction to show that glucose (C6H12O6) is being" +"synthesized? Write down a balanced equation to show this." +"" +"(Refer the lessons Chemical equations, Carbon and its compounds in" +"your textbook of physical science class X)." +"" +"" +"" +"" +"2 X Class Nutrition - Food supplying system" +" Van Neil first worked on purple sulphur bacteria and found light plays a specific" +"role in photosynthesis. Instead of H2O they used H2S as a starting material. Here no" +"" +"" +"" +"" +"A" +"oxygen is liberated during photosynthesis instead, elemental sulphur is evolved. Later" +"he envisioned a similar process of photosynthesis in plants and proposed the above" +"" +"" +"" +"" +"AN" +"mentioned equation. Later Robert Hill showed that O2 is released from water during" +"this reaction. Then the equation was modified as follows." +"Light" +"6CO2 + 12H2O C6H12O6 + 6H2O + 6O2" +"Chlorophyll" +"" +"" +"" +"" +"NG" +"It is known that plants synthesize carbohydrates, the smaller simpler" +"ones first and from them, the more complex ones like starch and cellulose." +"Plants are also capable of synthesizing all other compounds like proteins," +"fats etc." +"Animals are not capable of synthesizing carbohydrates and they have" +"to depend on plants for the same." +"LA" +"Can we state that photosynthesis is the basic energy source for most" +"of the living world? Why, why not?" +"Let us study how the plants prepare carbohydrates through" +"photosynthesis." +"TE" +"" +"Activity-1" +"Presence of starch (a type of carbohydrate) in leaves" +"Let us take a leaf from a plant with soft and thin leaves and well exposed" +"to sun light." +"T" +"" +"" +"Arrange apparatus as shown in figure 2 (a). Take methylated spirit in a" +"test tube and put the leaf in it." +"ER" +"" +"" +"" +"" +"beaker" +"boiling water" +"leaf iodine solution" +"methylated spirit" +"SC" +"" +"" +"" +"" +"boiling tube" +"petridish" +"asbestos gauze" +"tripod stand" +"bunsen burner" +"" +"" +"fig-2(a): boiling the leaf fig-2(b): Iodine test" +"in methylated spirit" +"" +"Free distribution by T.S. Government 2019-20 3" +" First boil the leaf in water then transfer this leaf into a test tube" +"containing methylated spirit. Boil this tube in a water bath. Chlorophyll" +"dissolves in spirit and the leaf becomes pale, due to removal of chlorophyll." +"" +"" +"" +"" +"A" +"Take the leaf carefully from test tube by using a brush." +"Spread the leaf in a petridish and add a few drops of iodine/ betadine" +"" +"" +"" +"" +"AN" +"solution on it. Observe the leaf." +"What do you see/notice?" +"The presence of starch will be indicated by a blue-black colour." +"Do you think solar energy transforms into chemical energy by the" +"" +"" +"" +"" +"NG" +"process of photosynthesis?" +"Factors (Materials) essential for the process of Photosynthesis" +"What are the materials that you think would be essential for the" +"synthesis of carbohydrates in the process of photosynthesis? (Hint: see" +"the equation proposed by Van Neil)" +"LA" +"Do you think the equation tells us about all the materials involved?" +"It took scientists over 300 years to find out about them. They opined" +"that we don’t know about several materials involved in the process still." +"Let us study how scientists experimented to find out about some of" +"the materials required for the process of photosynthesis." +"TE" +"" +"Water and Photosynthesis" +"In class VII we already studied how Von Helmont found that the water" +"is essential for the increase of plant mass." +"He did not know about photosynthesis then. Later, it was found that" +"increase in plant body mass or material occurred due to the process of" +"T" +"" +"" +"photosynthesis. We shall study more about it in the following sections." +"Read the chapter on ‘Nutrition in Plants’ in class VII. Discuss with" +"ER" +"" +"" +"" +"" +"your friends and write a note on Von Helmont’s experiment focussing on" +"how he concluded that water was important for plant growth and increase" +"in body mass." +"Air and Photosynthesis" +"SC" +"" +"" +"" +"" +"Let us discuss an experiment on photosynthesis. This one helps us to" +"find out about the role of air in the process of photosynthesis. It is" +"interesting to learn about the experiment which is one of the several" +"milestones in the gradual development of our understanding of" +"Photosynthesis." +"Joseph Priestly (1733-1804) in 1770 performed a series of experiments" +"that revealed the essential role of air on the growth of green plants" +"" +"4 X Class Nutrition - Food supplying system" +" (photosynthesis was still not known to scientists at" +"that time). You may recall, Oxygen was discovered" +"by Priestly in 1774. The name oxygen was coined" +"" +"" +"" +"" +"A" +"later by Lavoisier in the year 1775. Priestly observed" +"that a candle burning in a closed bell jar, soon gets" +"" +"" +"" +"" +"AN" +"extinguished. Similarly, a mouse would soon" +"suffocate in a closed space of the bell jar. He" +"concluded that a burning candle or an animal, both" +"somehow, damage air. When he placed a mint plant" +"in the same bell jars, he found that the mouse stayed" +"" +"" +"" +"" +"NG" +"alive and the candle when lighted from outside" +"continued burning in the presence of the mint plant." +"Priestly hypothesized as follows: ‘Plants restore the" +"air what breathing animals and burning candles" +"remove’. fig-3: Priestly experiment" +"LA" +"Do you find any relationship between candle, rat, mint plant ? Discuss." +"Do similar experiment in your school. Use a candle, plant in a small" +"pot and a bell jar. Note down your observations and explain." +"Priestly’s experiment confirmed that gaseous exchange was going on" +"TE" +"" +"and plants were giving out a gas that supported burning and was essential" +"for the survival of animals." +"But how do plants take in air and utilize carbon dioxide for" +"photosynthesis and oxygen for respiration?" +"How do they make the choice?" +"T" +"" +"" +"" +"Massive amounts of gaseous exchange occur through the stomata" +"(usually present in leaves) as long as they are open .While plants also" +"ER" +"" +"" +"" +"" +"carry on gaseous exchange through loose tissues in the stems, roots etc." +"It is actually at the level of the organelles involved in the process of" +"photosynthesis and respiration that the choice of the gas required is made." +"Activity-2" +"SC" +"" +"" +"" +"" +"Carbondioxide is necessary for Photosynthesis" +"We need a destarched plant to start with. We need to keep the plant in" +"the dark for nearly three days to remove the starch (destarch). By placing" +"the plant in dark the starch is removed from the leaves." +"Arrange the apparatus as shown in the figure 4." +"Take a wide mouthed transparent bottle." +"Free distribution by T.S. Government 2019-20 5" +" blue black" +"(starch formed)" +"split cork" +"" +"" +"" +"" +"A" +"potted plant" +"" +"" +"" +"" +"AN" +"wide mouthed" +"bottle" +"" +"KOH" +"colourless (no starch)" +"" +"" +"" +"" +"NG" +"fig-4: Mohl’s half leaf experiment" +"Put potassium hydroxide pellets or potassium hydroxide solution in" +"the bottle. Potassium hydroxide absorbs carbon dioxide." +"Insert splitted cork in the mouth of the bottle." +"Insert one of the leaf of destarched plant (through a split cork) into" +"LA" +"transparent bottle containing potassium hydroxide pellets/potassium" +"hydroxide solution." +"Leave the plant in sunlight." +"After a few hours, test this leaf and any other leaf of this plant for" +"TE" +"" +"presence of starch, as mentioned in activity-1." +"The leaf part which was exposed to the atmospheric air and light becomes" +"bluish-black, and the one inside the bottle containing potassium" +"hydroxide which absorbs carbon dioxide in the bottle remains" +"colourless. This proves that carbon dioxide is necessary for" +"T" +"" +"" +"" +"photosynthesis." +"Why was the plant kept in dark and then in sun light ?" +"ER" +"" +"" +"" +"" +"Why did we test two leaves in this experiment?" +"We have so far discussed the role of water and gases in the process of" +"photosynthesis. Scientist who had been working on these lines had observed" +"some other factors that affect the process of photosynthesis." +"SC" +"" +"" +"" +"" +"Light and Photosynthesis" +"In Priestley’s time, scientists didn’t understand about energy, but later" +"on much was discovered about it. If energy is released when carbon dioxide" +"and water is formed by combining oxygen with carbon and hydrogen, then" +"what about the reverse?. What about forming oxygen again and putting it" +"back in the air. Eventually, scientists learned that the energy situation would" +"also reverse. Oxygen formation would use up energy. That means if plants" +"6 X Class Nutrition - Food supplying system" +" form oxygen they have to get energy to make it possible. Where did the" +"energy come from?" +"A Dutch scientist, Jan Ingenhousz (1730-1799), found the answer. He" +"" +"" +"" +"" +"A" +"studied the way in which plants form oxygen. In 1779, he noticed that it" +"happened only in the presence of light. In an experiment with the aquatic" +"" +"" +"" +"" +"AN" +"plant, Hydrilla, he observed that in bright sunlight, small bubbles formed" +"around the green parts while in the dark they did not form. He also found" +"that the gas present in the bubbles was oxygen." +"It was further confirmed when Engelman in the early 20th century" +"ingeniously detected the point of maximum rate of photosynthesis. He" +"" +"" +"" +"" +"NG" +"used a strand of algae and exposed it to different colours of light (the" +"colours that we see in a rainbow) Then he used oxygen sensitive bacteria" +"and found that they crowd around areas illuminated with red and blue rays" +"of light. This led to more studies on effect of light on photosynthesis, the" +"role of different coloured compounds called pigments in plants and the" +"utilization of light energy." +"LA" +"Lab Activity" +"Oxygen is produced during photosynthesis in the presence of light" +"TE" +"" +"Arrange the apparatus as shown in the figure. Make" +"two identical sets. oxygen" +"" +"Place some water plant like Elodea or Hydrilla in bubbles" +"a short stemmed funnel and keep it in a beaker." +"Then pour the water in the beaker." +"T" +"" +"" +"test tube" +"Invert a test-tube full of water over the stem of the" +"funnel. Ensure that the level of water in the beaker beaker" +"ER" +"" +"" +"" +"" +"is above the level of stem of the inverted funnel. water" +"Place one apparatus in the sun and the other in the" +"funnel" +"dark for at least 2-3 hours. You would see that in place" +"of water there is air that fills in the set up kept in sun. It Hydrilla plant" +"" +"is actually a gas that will be collected in the test-tube." +"SC" +"" +"" +"" +"" +"Observe the other set up kept in dark. Is there any fig-5: Hydrilla experiment" +"difference in the amount of gas collected?" +"Test the gas in the test-tube by inserting a glowing match stick or" +"incense stick which would burst into flames. This shows the presence of" +"oxygen." +"What precautions do you need while removing test tube from the beaker." +"Discuss with your teacher." +"Free distribution by T.S. Government 2019-20 7" +" Activity-3" +"Sunlight is necessary to form starch in green plants" +"" +"" +"" +"" +"A" +"AN" +"NG" +"fig-6: Black paper experiment" +"" +"Take a potted plant with destarched leaves. Remember the process of" +"destraching leaves mentioned in activity-1." +"Cover one of its leaves with black paper on which a design is cut. Fix the" +"LA" +"paper on the leaf in such a manner that light does not enter the dark part." +"Place this potted plant in sun light." +"After few hours of exposure to bright sunlight, test the leaf which is" +"covered by black paper for the presence of starch." +"TE" +"" +"Which part of the leaf turns blue black? What about the remaining" +"part?" +"Observe the colour of leaf stained with iodine. Can you tell why it" +"is stained differently?" +"It will be observed that only the parts of the leaf, which could get light" +"T" +"" +"" +"" +"through the cut out design, turns blue-black showing the presence of" +"starch." +"ER" +"" +"" +"" +"" +"Chlorophyll and Photosynthesis" +"Ingenhousz wanted to find out more about photosynthesis and carried" +"out several other experiments. He proposed that only green plant parts" +"could carry out the process of photosynthesis." +"SC" +"" +"" +"" +"" +"What about plants having coloured leaves? How is it that new leaves" +"which look dark red in colour in several plants turn green? Do plants having" +"reddish or yellowish leaves also carry out photosynthesis? What made" +"plants carry out photosynthesis while even green coloured animals (like" +"some birds )could not? Questions like these remained challenges until" +"scientists could isolate the green coloured substance from plant parts and" +"study its nature." +"8 X Class Nutrition - Food supplying system" +" Establishment of Ingenhousz’s proposition came after several" +"experiments till the mid 20th century when scientists could also locate the" +"site of photosynthesis and even isolate it. Around four decades after" +"" +"" +"" +"" +"A" +"Ingenhouszs’ proposition scientists could only isolate the green substance" +"to observe its nature and find out whether photosynthesis could be carried" +"" +"" +"" +"" +"AN" +"out with it. This had become possible in the year 1817 due to the work of" +"two scientists Pelletier and Caventou who obtained an extract of the green" +"coloured substance and named it ‘chlorophyll’ meaning green leaf." +"It was also found that pigments in addition to chlorophyll, carotenoids" +"and phycobilins could also aid in the process of photosynthesis by passing" +"" +"" +"" +"" +"NG" +"on the energy of sunlight trapped by them to chlorophyll." +"Where does Photosynthesis take place?" +"Where is chlorophyll and other pigments present in the plant?" +"Try to name some parts where you think photosynthesis occurs." +"Do you think the new reddish leaves of plants also carry out" +"LA" +"photosynthesis? What could be the reason for their colour?" +"The exact location of the photosynthetic part or a part containing" +"chlorophyll was not known till another six decades after Pelletier and" +"Caventou discovered chlorophyll. It was believed to be spread in the cells" +"TE" +"" +"of green plant parts. In 1883, Julius Von Sachs, observed that chlorophyll" +"in plant cells is not spread through out the entire cell. It is rather found in" +"organelles within the cell. Such organelles were named as ‘chloroplasts’." +"These are present in large numbers in the cells (around 40 – 100) of parts" +"like the stomatal guard cells and ground tissues of plants ." +"You have studied about Chloroplast in Class IX. Let us observe the" +"T" +"" +"" +"" +"figure of TS of leaf showing Chloroplast in Palisade and Spongy" +"Parenchyma." +"ER" +"" +"" +"" +"" +"cuticle" +"" +"upper epidermis" +"" +"palisade parenchyma" +"" +"" +"" +"}" +"xylem" +"SC" +"" +"" +"" +"" +"Vascular bundle" +"phloem" +"spongy parenchyma" +"air spaces" +"guard cell" +"lower epidermis" +"stomata" +"fig-7: T-S of leaf cuticle" +"Free distribution by T.S. Government 2019-20 9" +" What makes chloroplast appear completely different from other cell" +"organelles?" +"" +"" +"" +"" +"A" +"Do you know?" +"If a cell is broken up, the chloroplasts also break into pieces, so it becomes a very" +"" +"" +"" +"" +"AN" +"difficult task to isolate them to study the different steps of photosynthesis.It was not" +"until 1954, that Daniel I. Arnon was able to break up plant cells so gently that whole" +"chloroplasts could be obtained that could carry through photosynthesis." +"" +"membrane stroma thylakoid It has been found that the chloroplast is" +"" +"" +"" +"" +"NG" +"lipid globule" +"stroma" +"a membranous structure, consisting of 3" +"membranes. The third layer forms stacked" +"} granum sack like structures called as grana. It is" +"believed to be a site for trapping of solar" +"energy. The intermediary fluid filled portion" +"grana thylakoid is called as stroma. It is believed to be" +"LA" +"starch grain responsible for enzymatic reactions leading" +"to the synthesis of glucose, which in turn" +"fig-8: T-S of chloroplast" +"join together to form starch." +"Substances found in chloroplast which capture sunlight are called" +"TE" +"" +"photosynthetic pigments. There are several types of photosynthetic" +"pigments involved in the process to produce organic molecules like" +"glucose in plants." +"Chlorophyll is such a pigment which contain one atom of magnesium." +"It is similar in structure to the haem of haemoglobin. (The iron containing" +"T" +"" +"" +"red pigment that transports oxygen in blood.) Two major kinds of" +"chlorophylls are associated with thylakoid membranes. Chlorophyll ‘a’ is" +"blue-green in colour and chlorophyll ‘b’ is yellow-green colour. Around" +"ER" +"" +"" +"" +"" +"250 to 400 pigment molecules are grouped as light harvesting complex or" +"photosynthetic unit in each thylakoid. Such innumerable units function" +"together in chloroplasts of green plants in the process of photosynthesis." +"During photosynthesis several events occur in the chloroplast some" +"SC" +"" +"" +"" +"" +"of them are:" +"1. Conversion of light energy to chemical energy" +"2. Splitting of water molecule (photolysis of water)" +"3. Reduction of carbondioxide to carbohydrates" +"Light is required to initiate several events while several may continue" +"even in absence of it. That would mean, once light energy has been captured" +"it can help reactions to continue even in the dark. Light dependent events" +"10 X Class Nutrition - Food supplying system" +" or reactions are called light reactions and it has been found to take place" +"in grana, while the rest are called light independent or dark reactions and" +"they occur in the stroma." +"" +"" +"" +"" +"A" +"Mechanism of Photosynthesis" +"" +"" +"" +"" +"AN" +"1. Light dependent reaction (Photochemical phase)" +"In this reaction light plays a key role. A series of chemical reactions" +"occur in a very quick succession initiated by light and therefore the phase" +"is technically called the photochemical phase or light dependent reaction." +"The light reaction takes place in chlorophyll containing thylakoids called" +"" +"" +"" +"" +"NG" +"grana of chloroplasts. Several steps occur in the light dependent reaction." +"Step-I : The chlorophyll on exposure to light energy becomes activated" +"by absorbing photons. (Photon is the smallest unit of light energy)" +"Step-II: The energy is used in splitting the water molecule into two" +"component ions named hydrogen (H+), hydroxyl ion (OH-)." +"LA" +"H2O H+ + OH--" +"The reaction is known as photolysis, which means splitting by" +"light (photo means light, lysis means breaking). This was" +"discovered by Robert Hill. Hence it is also called Hill’s reaction." +"Step-III: The highly reactive H+, OH-- ions of water undergo quick change" +"TE" +"" +"as described below." +"OH ions through a series of steps produce water (H20) and Oxygen" +"-" +"" +"(O2). Water may be used by the plant inside, but O2 is usually released" +"into the atmosphere. H+ ions undergo series of changes in dark reaction." +"H+ ions produced in photolysis are immediately picked up by special" +"T" +"" +"" +"compound NADP to form NADPH (reduced Nicotinamide Adenosine" +"Dinucleotide Phosphate). ADP and iP trap energy to form ATP (Adenosine" +"Tri phosphate). ATP and NADPH are formed at the end of the light" +"ER" +"" +"" +"" +"" +"reaction. These are (ATP, NADPH) called Assimilatory power." +"2. Light independent reaction (Biosynthetic phase)" +"This reaction does not require the presence of light and extension of" +"the phases after day time may occur in some plants (time gap between the" +"SC" +"" +"" +"" +"" +"two being less than even one thousandth of a second) and some times even" +"in the dark." +"This is also called dark reaction. But the term dark reaction or light" +"independent reaction does not mean that they occur when it is dark at night." +"It only means that these reactions are not depend on light. In the dark phase" +"the hydrogen of the NADPH is used to combine it with CO2 by utilizing" +"ATP energy and to produce glucose (C6H12O6). This synthesis occurs in a" +"Free distribution by T.S. Government 2019-20 11" +" number of steps using certain special intermediate compounds and" +"enzymes. RUBP (Ribulose 1-5 bis Phosphate) is the compound which" +"accepts CO2 in this process. Finally the glucose is converted to starch." +"" +"" +"" +"" +"A" +"Plants are capable of surviving under a range of situations, from very" +"hot, dry and brightly lighted conditions to wet, humid and dimly lighted" +"" +"" +"" +"" +"AN" +"ones. The requirement of light and other factors varies from one plant to" +"another." +"Heterotrophic Nutrition" +"In the living world all organisms are capable of surviving under different" +"conditions and acquring their food in different ways. We have studied about" +"" +"" +"" +"" +"NG" +"organisms that can capture light to produce their food. These are" +"pseudopodia" +"autotrophic in nature. While those that can not are heterotrophic." +"How do organisms obtain their nutrition" +"Depending on the type and availability of food organisms can assort" +"food particle to a range of strategies of food intake and use. Some organisms break" +"LA" +"down the food materials outside the body and then absorb it. For example," +"bread moulds, yeast, mushrooms etc. which are called saprophytes. Some" +"other organisms derive nutrition from plants or animals without killing" +"food vacuole them. This type of parasitic nutritive strategy is used by a wide variety of" +"TE" +"" +"organisms like Cuscuta, lice, leeches and tape worms. Others take in whole" +"nucleus" +"material and break it down inside their bodies. What can be taken in and" +"fig-9(a): broken down depends on the bodys’ design and it’s function." +"Nutrition in Since the food and the way it is obtained differs, the digestive system" +"Ameoba" +"is also different in various organisms. In single celled organisms, like" +"amoeba the food may be taken in by the entire surface but as the complexity" +"T" +"" +"" +"" +"fig-9(b): of the organism increases, different parts become specialized to perform" +"Nutrition in different functions." +"ER" +"" +"" +"" +"" +"Paramoecium" +"For example amoeba [fig-9(a)] takes in food using" +"temporary finger like extensions (pseudopodia) of the cell" +"Food" +"vacuole surface which fuse over the food particle forming food vacuole." +"Inside the food vacuole, complex substances are broken down" +"into simpler ones. Then diffuse into the cytoplasm. The" +"SC" +"" +"" +"" +"" +"Oral remaining undigested material is moved to the surface of the" +"groove" +"cell and thrown out. In Paramoecium [fig-9(b)], which is also a" +"Formation" +"of food" +"unicellular organism the cell has a definite shape. Food is taken" +"vacuole" +"in at a specific spot. Food is moved to the spot by the movement" +"Anal pore of cilia which covers the entire surface of the cell, where the" +"food is ingested (cytostome)." +"" +"12 X Class Nutrition - Food supplying system" +" Parasitic nutrition in Cuscuta" +"Dodder (genus Cuscuta) is a leafless, twining, parasitic plant" +"belongs to morning glory family (Convolvulaceae). The genus" +"" +"" +"" +"" +"A" +"contains about 170 twining species that are widely distributed" +"throughout the temperate and tropical regions of the world." +"" +"" +"" +"" +"AN" +"fig-10: Haustoria" +"The dodder plant contains no chlorophyll. Cuscuta reflexa" +"in cuscuta" +"has been found to have very little amount of chlorophyll and instead absorbs" +"food through haustoria. They are root like structures that penetrate the tissue" +"of a host plant and may kill it. The slender, string like stems of the dodder" +"may be yellow, orange, pink, or brown in colour. It’s leaves are reduced to" +"" +"" +"" +"" +"NG" +"minute scales. The dodder’s flowers, in nodule like clusters, are made up of" +"tiny yellow or white bell-like petals." +"The dodder’s seed germinates, forming an anchoring root, and then" +"sends up a slender stem that grows in a spiral fashion until it reaches a" +"host plant. It then twines around the stem of the host plant and forms" +"LA" +"haustoria, which penetrate through it. Water is drawn through the haustoria" +"from the host plant’s xylem, and nutrients are drawn from its phloem." +"Meanwhile, the root rots away after contact has been made with a host" +"stem. As the dodder grows, it sends out new haustoria (parasitic roots) and" +"TE" +"" +"establishes itself very firmly on the host plant. After growing in a few" +"spirals around one host shoot, the dodder finds its way to another, and it" +"continues to twine and branch until it resembles a fine, densely tangled" +"web of thin stems enveloping the host plant. Identify plants in your" +"surroundings which are parasitic on other plants." +"Nutrition in Human Beings" +"T" +"" +"" +"" +"Human digestive system is very" +"ER" +"" +"" +"" +"" +"complex in nature. Different parts are Mouth" +"Salivary gland" +"involved and perform different functions by" +"using various digestive juices and enzymes. Oesophagus" +"Stomach" +"Let us observe the figure of digestive" +"Pancreas" +"system. Liver" +"SC" +"" +"" +"" +"" +"The alimentary canal is basically a long" +"tube extending from the mouth to the anus." +"We can see that this tube has different parts. Large intestine" +"Various regions are specialized to perform Small intestine" +"different functions." +"Rectum" +"What happens to the food once it enters Anus" +"our body? fig-11: Alimentary canal of man" +"" +"Free distribution by T.S. Government 2019-20 13" +" We eat various types of food which has to pass through the same" +"digestive tract. It also has to be converted to substances small enough" +"to be utilised by our body. This needs various processess that can be" +"" +"" +"" +"" +"A" +"studied as follows." +"Passage of food through alimentary canal or gut" +"" +"" +"" +"" +"AN" +"salivary duct" +"Food is cut and crushed by our teeth in the" +"mouth and mixed with saliva to make it wet and" +"slippery lump called bolus (This process is called" +"palate salivary" +"uvula as mastication). This bolus is suitable to pass" +"glands" +"tongue through oesophagus. Saliva is secreted by three pairs" +"" +"" +"" +"" +"NG" +"epiglottis of salivary glands. First pair is located at the side of" +"the jaw called as submandibular," +"submandibular second pair is" +"fig-12: Buccal cavity located below the tongue called as sublingual and" +"third pair is located at the side of the ear called parotid glands. Saliva" +"mainly contains an enzyme amylase (ptyalin) which helps in the breakdown" +"LA" +"of complex carbohydrates to simple ones. This process of breaking down" +"of complex substances into simple substance with the help of enzymes" +"and obsorbed into the body is called digestion. The tongue helps in mixing" +"the food and pushing it into the next part. The lower jaw also helps in the" +"whole process." +"TE" +"" +"We can find out the effect of salivary amylase on carbohydrates to" +"observe what might be happening in our mouth." +"p To know the chemical nature of the saliva perform the activity-" +"7 of co-ordination in life process of this text book." +"The soft food mixed with saliva passes through oesophagus or food" +"T" +"" +"" +"pipe by wave like movements called peristaltic movement to the stomach." +"At the stomach, food gets churned with gastric juice and HCl. Now" +"the food is in semisolid condition. The digestion of food goes on as most" +"ER" +"" +"" +"" +"" +"proteins are broken down into smaller molecules with the help of enzyme" +"pepsin acting on them." +"peristaltic wave oesophagus Food in the form of a soft slimy substance where some" +"proteins and carbohydrates have already been broken down" +"SC" +"" +"" +"" +"" +"is called chyme. Now the food material passes from the" +"stomach stomach to the small intestine. Here the ring like muscles" +"called pyloric sphincters relax to open the passage into" +"the small intestine. The sphincters are responsible for" +"regulating the opening of the passage such that only small" +"bolus" +"quantities of the food material may be passed into the" +"fig-13: Peristaltic movement small intestine at a time." +"14 X Class Nutrition - Food supplying system" +" The small intestine is the longest part of the alimentary canal. Its" +"proximal part is called duodenum. It is the site of further digestion of" +"carbohydrates, proteins and fats. It receives the secretion of liver and" +"" +"" +"" +"" +"A" +"pancreas for this purpose. These juices render the internal condition of the" +"intestine gradually to a basic or alkaline one." +"" +"" +"" +"" +"AN" +"Fats are digested by converting them into small globule like forms by the" +"help of the bile juice secreted from liver. This process is called emulsification." +"Pancreatic juice secreted from pancreas contains enzymes like trypsin" +"for carrying on the process of digestion of proteins and lipase for fats." +"Walls of the small intestine secrete intestinal juice called" +"" +"" +"" +"" +"NG" +"succusentericus which carry this process further that is small molecules of" +"proteins are broken down to further smaller molecules. The same is the" +"condition with fats. Carbohydrate digestion that started in the mouth and did" +"not occur in the stomach, resumes now as the medium gradually changes to" +"an alkaline one and the enzymes become active for carbohydrate breakdown." +"Activity-4" +"LA" +"Studying the enzymes chart" +"Let us study the chart showing different enzymes and digestive juices" +"and their functions." +"TE" +"" +"Table-1: Digestive enzymes" +"S.No. Enzyme/Substance Secreted by Secreted into Digestive juice Acts on Products" +"1 Ptyalin Salivary glands Buccal cavity Saliva Carbohydrates Maltose" +"(salivary amylase)" +"2 Pepsin Gastric glands Stomach Gastric juice Proteins Peptones" +"T" +"" +"" +"" +"3 Bile Liver Duodenum Bile juice Fats Emulsification" +"(No enzymes) breaking down" +"ER" +"" +"" +"" +"" +"of large fats" +"into small" +"globules" +"4 Amylase Pancreas Duodenum Pancreatic juice Carbohydrates Maltose" +"5 Trypsin" +"Trypsin Pancreas Duodenum Pancreatic juice Proteins Peptones" +"SC" +"" +"" +"" +"" +"6 Lipase Pancreas Duodenum Pancreatic juice Fats Fatty acids" +"and glycerol" +"7 Peptidases Intestinal glands Small Intestine Intestinal juice Peptides Amino acids" +"8 Sucrase Intestinal glands Small Intestine Intestinal juice Sucrose Glucose" +"(Cane Sugar)" +"" +"Name the enzymes which act on carbohydrates?" +"Free distribution by T.S. Government 2019-20 15" +" Which juice contains no enzymes?" +"What are the end products of fats?" +"What are the enzymes that act on proteins?" +"" +"" +"" +"" +"A" +"Transport of the products of digestion from the intestine into blood" +"(through the wall of intestine) is called absorption. Internally, intestinal" +"" +"" +"" +"" +"AN" +"wall has a number of finger like projections called Microvilli. The villi" +"increase the surface area for absorption. Blood vessels and lymph vessels" +"are present in the form of a network in the villi." +"Products of digestion are absorbed first into the villi and from here" +"into the blood vessels and lymph vessels. Thus after maximum absorption" +"" +"" +"" +"" +"NG" +"of food in the small intestine the rest passes into the large intestine. Here" +"most of the water present is taken up from this material. This material is" +"then expelled through the anus which is the last part of the alimentary" +"canal. This passage of undigested material from the body by the way of" +"anus is called defecation. Food that passes out of the anus still contains" +"considerable amount of proteins, fats and carbohydrates, roughages or" +"LA" +"fibres of either carbohydrates or proteins. We will learn some more points" +"about the coordination about digestive system with other systems in the" +"chapter coordination in life processes." +"Flow chart of human digestive system" +"TE" +"" +"What do you think is the process of digestion?" +"What are its major steps?" +"" +"Food Mouth Buccal cavity Pharynx" +"T" +"" +"" +"" +"Stomach Oesophagus" +"ER" +"" +"" +"" +"" +"Duodenum Small intestine Large intestine" +"" +"" +"Anus Rectum" +"SC" +"" +"" +"" +"" +"Liver Pancreas" +"" +"Health aspects of the alimentary canal" +"The human alimentary canal usually functions remarkably well" +"considering how badly we treat it on occasions! Sometimes it rebels," +"and we either feel sick or have indigestion." +"16 X Class Nutrition - Food supplying system" +" Vomiting is the body’s method of ridding itself of unwanted or harmful" +"substances from the stomach. The peristaltic movements of the stomach" +"and oesophagus reverse their normal direction and the food is expelled." +"" +"" +"" +"" +"A" +"There are many causes of vomiting, but one of the most common is over" +"eating, especially when the food contains a high proportion of fat. Vomiting" +"" +"" +"" +"" +"AN" +"also occurs when we eat something very indigestible or poisonous." +"When we have a greenish vomit usually called as ‘bilious’ or ‘liverish’," +"we get a bitter taste and it is often the result of having over eaten. The liver" +"is unable to cope with the excessive fat and we get a feeling of nausea." +"Indigestion is a general term used when there is difficulty in digesting" +"" +"" +"" +"" +"NG" +"food. Healthy people can usually avoid problems related to digestion by:" +"a) having simple, well balanced meals" +"b) eating food in a leisurely manner" +"c) thoroughly masticating the food" +"LA" +"d) avoiding taking violent exercise soon after eating food" +"e) Drinking plenty of water and having regular bowel movements." +"A more serious form of indigestion is caused by stomach and duodenal" +"ulcers. These conditions occur more often in people who may be described" +"TE" +"" +"as hurried or worried. Thus, ulcers occur more often in busy people who" +"get into the habit of hurrying over meals and rushing from one activity to" +"another without sufficient rest. Those who are able to relax, who are not" +"continually tensed up, and who live at a slower pace, seldom get ulcers." +"You studied about recent researches in the peptic ulcers caused by some" +"T" +"" +"" +"bacteria in previous classes." +"Proper functioning of all life processes require adequate amount of" +"ER" +"" +"" +"" +"" +"food in all living organisms. It is not just the intake of food but its" +"assimilation and expulsion of wastes that play an important role. In take of" +"fibre rich food avoids constipation." +"Diseases due to malnutrition" +"We know that food is the main source to maintain biological processes" +"SC" +"" +"" +"" +"" +"in a perfect manner. Our diet should be a balanced one which contains" +"proper amount of carbohydrates, proteins, vitamins, mineral salts and fats." +"Two third of world population is affected by food related diseases. Some" +"of them are suffering by consuming high calorific food. Most of them are" +"facing various diseases due to lack of balanced diet. It is very important to" +"discuss about food deficiency diseases." +"" +"Free distribution by T.S. Government 2019-20 17" +" Eating of food that does not have one or more than one nutrients in" +"required amount is known as malnutrition. Poor health, will full starvation," +"lack of awareness of nutritional habits, socio-economic factors are all the" +"" +"" +"" +"" +"A" +"reasons for malnutrition in our country." +"Malnutrition is of three types" +"" +"" +"" +"" +"AN" +"1. Protein malnutrition," +"2. Calorie malnutrition," +"3. Protein calorie malnutrition." +"Let us observe harmfull effects of malnutrition in children." +"" +"" +"" +"" +"NG" +"1. Kwashiorkor disease: This is due to protein deficiency in" +"diet. Body parts become swollen due to accumulation of water" +"in the intercellular spaces. Very poor muscle development," +"swollen legs, fluffy face difficult to eat, diarrhoea, dry skin are" +"fig-14: Kwashiorkor" +"the symptoms of this disease." +"2. Marasmus: This is due to deficiency of both proteins and" +"LA" +"calories. Generally this disease occurs when there is an" +"immediate second pregnancy or repeated child births. Lean and" +"weak, less developed muscles, dry skin, diarrhoea, etc., are the" +"symptoms of this disease." +"TE" +"" +"Obesity: This is due to over eating and excess of clories in take." +"It is a big health hazard. Obese children when grow, they will be" +"fig-15: Marasmus" +"target of many diseases like diabetes, cardio vascular, renal, gall" +"bladder problems. Discuss about junk foods and other food" +"habits which leads to obesity." +"T" +"" +"" +"Vitamin deficiency diseases" +"fig-16: Obesity" +"Vitamins are organic substances. They are micro nutrients" +"ER" +"" +"" +"" +"" +"required in small quantities. Actually vitamins are not synthesised" +"in the body, we do not generally suffer from vitamin deficiency." +"The source of vitamins to our body is through two ways. One" +"is diet and other is bacteria present in the intestine that" +"synthesises and supplies vitamins to the body." +"SC" +"" +"" +"" +"" +"fig-17: Pellagra" +"Vitamins are classified into two groups. One is Water soluble vitamins" +"(B-complex, vitamin C) and other is fat soluble vitamins (vitamin A, D," +"E and K). If food we take doesn’t contain vitamins in right proportion, it" +"can lead to vitamin deficiency disorders. Let us study the following chart" +"showing vitamins available sources and deficiency diseases." +"" +"18 X Class Nutrition - Food supplying system" +" Table-2: Vitamins" +"" +"Vitamin Resources Deficiency Symptoms" +"diseases" +"" +"" +"" +"" +"A" +"Thiamin (B1) Cereals, oil seeds, vegetables, Beri beri Vomitings, fits, loss of appe-" +"milk, meat, fish, eggs. tite, difficulty in breathing," +"" +"" +"" +"" +"AN" +"paralysis." +"" +"Riboflavin (B2) Milk, eggs, liver, kidney, green Glossitis Mouth cracks at corners, red" +"leafy vegetables. and sore tongue, photophobia," +"scaly skin." +"" +"" +"" +"" +"NG" +"Niacin (B3) Kidney, liver, meat, egg, fish, Pellagra Dermatitis, diarrhoea, loss of" +"oil seeds. memory, scaly skin." +"" +"Pyridoxine (B6) Cereals, oil seeds, vegetables, Anaemia Hyper irritability, nausea," +"milk, meat, fish, eggs, liver. vomiting, fits." +"" +"Cyanocobalamin Synthesised by bacteria Pernicious anaemia Lean and weak, less appetite." +"(B 12 )" +"LA" +"present in the intestine." +"" +"Diarrhoea, loss of leucocytes," +"Folic acid Liver, meat, eggs, milk, fruits, Anaemia problems related to mucus in" +"cereals, leafy vegetables. the intestines." +"TE" +"" +"Pantothenic acid Sweet potatoes, ground nuts, Burning feet Walking problems, sprain." +"vegetables, liver, kidney, egg." +"" +"Biotin Pulses, nuts, vegetables, liver, Nerves disorders Fatigue, mental depression," +"milk, kidney. muscle pains." +"" +"Ascorbic acid (C) Green leafy vegetables, citrus Scurvy Delay in healing of wounds," +"T" +"" +"" +"fruits, sprouts. fractures in bones." +"" +"Retinol (A) Leafy vegetables, carrot, Eye, skin diseases Night blindness," +"ER" +"" +"" +"" +"" +"Tomato, pumpkin, papaya, xerophthalmia, cornea failure," +"mango, meat, fish, egg, liver, scaly skin." +"milk, cod liver oil, shark liver" +"oil." +"" +"Calciferol (D) Liver, egg, butter, cod liver oil, Rickets Improper formation of bones," +"(sunshine vitamin) shark liver oil, sun rays stimu- Knock-knees, swollen wrists," +"SC" +"" +"" +"" +"" +"late the formation of vitamin delayed dentition, weak" +"D from the sub-cutaneous fat. bones." +"" +"Tocoferol (E) Fruits, vegetables, sprouts, Fertility related Sterility in males, abortions in" +"sunflower oil. disorders females." +"" +"Phylloquinone (K) Green leafy vegatables, milk, problems related to Delay in blood clotting, over" +"meat, egg. Blood clotting bleeding." +"" +"Free distribution by T.S. Government 2019-20 19" +" Key words" +"" +"" +"" +"" +"A" +"Glucose, starch, cellulose, chloroplast, grana, stroma, light reaction, dark reaction," +"heterotrophic nutrition, parasitic nutrition, haustoria, Alimentary canal, salivary glands," +"peristaltic movement, amylase, ptyalin, pepsin, chyme, sphincter, digestion, pancreas," +"" +"" +"" +"" +"AN" +"enzymes, villi, bile juice, lipase, fat, liver, emulsification, kwashiorkor, marasmus." +"" +"" +"" +"What we have learnt" +"" +"" +"" +"" +"NG" +"Autotrophic nutrition involves the intake of simple inorganic materials like some minerals, water" +"from the soil. Some gases from the air. By using an external energy source like the Sun to synthesis" +"complex high energy organic material." +"Photosynthesis is the process by which living plant cells containing chlorophyll, produce food" +"substances [glucose & starch] from Carbon dioxide and water by using light energy. Plants release" +"oxygen as a waste product during photosynthesis." +"LA" +"Photosynthesis process can be represented as" +"light" +"6CO2 + 12H2O Chlorophyll C6H12O6+6H2O+6O2" +"The materials required for photosynthesis are light: Carbon dioxide, Water, photosynthetic pigment" +"chlorophyll." +"TE" +"" +"Chloroplasts are the sites of photosynthesis. Light reaction takes place in the grana region and light" +"independent reaction takes place in the stroma region." +"The end products of photosynthesis are Glucose water and Oxygen." +"During photosynthesis the important events which occurs in the chloroplast are" +"a) Conversion of light energy into chemical energy" +"T" +"" +"" +"" +"b) Splitting of water molecule" +"c) Reduction of carbon dioxide to carbohydrates" +"ER" +"" +"" +"" +"" +"Heterotrophic Nutrition involves the intake of complex material prepared by other organisms." +"The form of nutrition differs depending on the type and availability of food material as well as how" +"it is obtained by the organism." +"In single celled organisms the food may be taken in by the entire surface but as the complexity of" +"SC" +"" +"" +"" +"" +"the organism increases different parts becomes specialized to perform different functions." +"The large complex food molecules such as carbohydrates, proteins , lipids, etc., are broken down" +"in to simple molecules before they are absorbed and utilized by the animals. This process of" +"breaking down of complex molecules into simple molecule is called digestion." +"In human beings the food eaten is broken down in various steps with the help of enzymes secreted" +"by digestive glands which are associated with the alimentary canal and the digested food is absorbed" +"in small intestine to be sent to all cells in the body." +"" +"20 X Class Nutrition - Food supplying system" +" The digestive system includes the alimentary tract and several associated organs and digestive" +"glands. The functions of system are as follows :" +"a) Ingestion: Taking of food into the body" +"" +"" +"" +"" +"A" +"b) Digestion: Breaking up of complex food substances into the simple substances by specific" +"enzymes. So that they can be used by the body." +"" +"" +"" +"" +"AN" +"c) Absorption: The passage of digested food through the walls of alimentary tract (particularly" +"in small intestine ) into circulatory system." +"d) Defecation: The passage of undigested material from the body by the way of anus." +"" +"" +"Improve your learning" +"" +"" +"" +"" +"NG" +"1. Write differences between (AS1)" +"a) autotrophic nutrition - heterotrophic nutrition b) Ingestion - digestion" +"c) Light reaction - dark reaction d) Chlorophyll - chloroplast" +"2. Give reasons (AS1)" +"a) Why photosynthesis is considered as the basic energy source for most of living world?" +"LA" +"b) Why is it right to call the dark phase of photosynthesis as a light independent phase?" +"c) Why is it necessary to destarch a plant before performing any experiment on photosynthesis?" +"d) Why is not possible to demonstrate respiration in green plant kept in sun light?" +"3. Give examples (AS1)" +"TE" +"" +"a) Digestive enzymes b) Organisms exhibiting heterotrophic nutrition" +"c) Vitamins d) Nutritional deficiency diseases" +"4. From where do plants get the raw materials required for photosynthesis?(AS1)" +"5. Explain the process of photosynthesis in with the help of a flow chart? (AS1)" +"6. Name the three end products of photosynthesis? (AS1)" +"T" +"" +"" +"7. What is the substance that connects light reaction and dark reaction? (AS1)" +"8. In most of leaves the upper surface will be more green and shiny than the lower surface. Why?" +"(AS1)" +"ER" +"" +"" +"" +"" +"9. Explain the structure of chloroplast with a neatly labeled sketch. (AS5)" +"10. What is the role of acid in stomach? (AS1)" +"11. Mention the names of glands and organs which help in digestion? (AS1)" +"12. How is the small intestine designed to assimilate the food? explain. (AS1)" +"13. How are fats digested? Where do they get digested? (AS1)" +"SC" +"" +"" +"" +"" +"14. What is the role of saliva in the digestion of food? (AS1)" +"15. What will happen to protein digestion as the medium of intestine is gradually rendered alkaline?" +"(AS1)" +"16. What is the role of roughages in the alimentary tract? (AS1)" +"17. What is malnutrition? Explain few nutritional deficiency diseases. (AS1)" +"18. How do fungi and bacteria obtain their nourishment? (AS2)" +"19. If we keep on increasing CO2 concentration in air what will be the rate of photosynthesis?(AS2)" +"Free distribution by T.S. Government 2019-20 21" +" 20. What happens if the rate of respiration is more than the rate of photosynthesis in a plant?(AS2)" +"21. How can you say that the carbohydrates are not digested in the stomach?(AS1)" +"22. What process do you follow in the laboratory to study the presence of starch in leaves?(AS3)" +"" +"" +"" +"" +"A" +"23. How would you demonstrate that green plant releases oxygen when exposed to light?(AS3)" +"24. Visit a primary health centre and collect the information about the children at diffrent ages suffering" +"" +"" +"" +"" +"AN" +"from malnutrition. (AS4)" +"No. of children with malnutrition" +"S.No. Age group" +"Protiens Calories Vitamins" +"Vitamins" +"1" +"2" +"" +"" +"" +"" +"NG" +"25. Would the survival of organisums become difficult, if there are no green plants on the earth? How" +"do you support it?(AS1)" +"26. Draw the labelled diagram of human digestive system? List out the parts where peristalsis takes" +"place. (AS5)" +"27. Raheem prepared a model showing the passage of the food through different parts of the alimentary" +"LA" +"canal? Observe this and label it’s parts. (AS5)" +"TE" +"" +"28. Observe the following diagram and write a note on light dependent, light independent reactions.(AS5)" +"" +"light" +"T" +"" +"" +"" +"Calvin" +"Cycle" +"ER" +"" +"" +"" +"" +"Chloroplast" +"photo chemical reaction thermo chemical reaction" +"" +"" +"Photochemical reaction Thermochemical reaction" +"SC" +"" +"" +"" +"" +"29. What facts about the green plants do you appreciate?(AS6)" +"30. What food habits do you follow after reading this chapter? Why? (AS7)" +"" +"" +"" +"" +"22 X Class Nutrition - Food supplying system" +" Fill in the blanks" +"" +"" +"" +"" +"A" +"1. The food synthesized by the plant is stored as ______________________." +"2. ________________________ are the sites of photosynthesis." +"" +"" +"" +"" +"AN" +"3. The enzymes in the pancreatic juice help in the digestion of ___________________ and" +"________________________." +"4. The finger like projections which increases the surface area in small intestine are" +"called____________________." +"5. The gastric juice contains _________________________ acid." +"" +"" +"" +"" +"NG" +"6. ___________________ vitamin is synthesised by bacteria present in intestine." +"" +"" +"Choose the correct answer LA" +"7. Which of the following organisms take the food by parasitic nutrition? ( )" +"(i) Yeast (ii) Mushrooms (iii) Cuscuta (iv) Leeches" +"A) (i), (ii) B) (iii) C) (iii), (iv) D) (i)" +"8. The rate of Photosynthesis is not affected by: ( )" +"TE" +"" +"A) Light Intensity B) Humidity C) T" +"Temperature" +"emperature D) Carbon dioxide concentration" +"9. A plant is kept in dark for about forty eight hours before conducting any experiment on Photosynthesis" +"in order to : ( )" +"A) Remove chlorophyll from leaves" +"T" +"" +"" +"" +"B) Remove water from leaves" +"ER" +"" +"" +"" +"" +"C) Ensure that no photosynthesis occurred" +"D) Ensure that leaves are free from the starch" +"10. The digestive juice without enzyme is ( )" +"A) Bile B) Gastric juice C) Pancreatic juice D) saliva" +"SC" +"" +"" +"" +"" +"11. In single celled animals the food is taken by ( )" +"A) body surface B) Mouth C) Teeth D) Vacuoles" +"12. Which part of the plant takes in carbondioxide from the air for photosynthesis ( )" +"A) Root hair B) Stomata C) Leaf veins D) Sepals" +"" +"" +"" +"Free distribution by T.S. Government 2019-20 23" +" A" +"Chapter" +"" +"" +"" +"" +"AN" +"2" +"" +"" +"NG" +"Respiration-The energy producing system" +"" +"Using food to carry out life processes is key to life for all living beings" +"in both multicellular or unicellular. In the chapter, on nutrition we have" +"LA" +"discussed how the body draws out nutrients from the food taken in. The" +"food provides energy for all the biological activities only after break down" +"through the process known as respiration. Thus, respiration leads to final" +"utilization of food. Normally respiration takes place in oxygen rich" +"TE" +"" +"enveronment. Cells of the living body use food constantly to help our" +"body to function properly. They require the presence of gas, food material" +"and some chemicals." +"The term ‘respiration’ derived from Latin word ‘respire’ meaning ‘to" +"breathe’, refers to the whole chain of processes from the inhalation of air" +"T" +"" +"" +"to the use of oxygen in the cells. To begin with, we shall study the relation" +"of gases and the process of respiration." +"ER" +"" +"" +"" +"" +"Discovery of gases and respiration" +"The term respiration came into use, a century after the word breathing" +"was used, way back in the 14th century. It was used much before people" +"knew that air is a mixture of gases. They hardly knew anything about all" +"SC" +"" +"" +"" +"" +"the life processes that took place internally in a living body. Respiration" +"which was used as a medical term, usually referred to as a process" +"involving passage of air and production of body heat." +"It was not until 18th century when Lavoisier and Priestley did a" +"comprehensive work on properties of gases, their exchange and" +"respiration that we came to know something about how the process of" +"fig-1: Lavoisier" +"gaseous exchange goes on, in our body. You have already studied about" +"" +"24 X Class Respiration - The energy releasing system" +" some of Priestley’s experiments in earlier classes (You have an account" +"of it in the chapter on nutrition as well). Recall the concepts and answer" +"the following." +"" +"" +"" +"" +"A" +"Can it be said that Priestley’s experiment helped us to find out more" +"about composition of air? How?" +"" +"" +"" +"" +"AN" +"Lavoisier also carried out several experiments to understand the" +"property of gases. In his early experiments, it is clear that Lavoisier thought" +"that the gas liberated on heating powdered charcoal in a belljar kept over" +"water in a trough was like fixed air. In those days carbon dioxide was known" +"as fixed air. The next series of experiments dealt with the combustion of" +"" +"" +"" +"" +"NG" +"phosphorus in a belljar. From these studies Lavoisier showed that whatever" +"in the atmospheric air which combined with the phosphorus, was not water" +"vapour. His final words are that the substance which combines with the" +"phosphorus is “either air itself, or another elastic fluid present, in a certain" +"proportion, in the air which we breathe”. This was the respirable air, a" +"LA" +"component of air that also helped in burning." +"What was produced by combustion according to Lavoisier?" +"What did Lavoisier find out about air from his experiments?" +"What conclusion can be drawn from Lavoisier’s experiments?" +"TE" +"" +"Lavoisier noted that there was a profound difference between the air" +"in which combustion of a metal had been carried out and the one which fig-2: Priestley" +"had served for respiration. The air that we breathe out precipitated lime" +"water while that after heating metal did not." +"From this he deduced that there were two processes involved in" +"respiration, and that of these he probably knew only one. Therefore, he" +"T" +"" +"" +"" +"carried out another experiment by which he showed that about one sixth" +"of the volume of ‘vitiated air’(a term used then to show air from which the" +"ER" +"" +"" +"" +"" +"component needed for burning had been removed) consists of chalky acid" +"gas (fixed air). Therefore, to recreate common air from vitiated air, it was" +"not enough merely to add the appropriate amount of air needed for burning" +"or respirable air; the existing chalky acid gas must also be removed." +"He drew immediately the logical conclusion regarding the process of" +"SC" +"" +"" +"" +"" +"respiration. Either eminently respirable air is changed in the lungs to chalky" +"acid air; or an exchange takes place, the eminently respirable air being" +"absorbed, and an almost equal volume of chalky acid air being given up to" +"the air from the lungs. He had to admit that there were strong grounds for" +"believing that eminently respirable air did combine with the blood to" +"produce the red colour. (But in due course the scientists identified that" +"due to haemoglobin the blood is red in colour.)" +"Free distribution by T.S. Government 2019-20 25" +" Lavoisier’s findings lead way to several other researchers." +"Which gas do you think is Lavoisier talking about when he says" +"chalky acid gas?" +"" +"" +"" +"" +"A" +"Which gas according to him is respirable air?" +"What steps in the process of respiration does Lavoisier mention as" +"" +"" +"" +"" +"AN" +"an inference of his experiments?" +"A few lines from a textbook of Human Physiology, written by a" +"renowned chemist, John Daper around mid-19th century goes like this.." +"‘‘The chief materials which a living being receives are matter that" +"can be burnt, water and oxygen gas; and out of the action of these" +"" +"" +"" +"" +"NG" +"upon one another, all the physical phenomena of its life arise. What the" +"body expels out is water, oxide of carbon, phosphorous, sulphur and" +"others.’’" +"Thus, we can see that the role of major compounds and elements in" +"the process of respiration was known by mid19thcentury. The events" +"LA" +"involved were not very clearly understood, but, people believed that there" +"was some relationship of the heat produced in the body and the process of" +"respiration." +"It is a common observation that our breath is warmer than the air" +"TE" +"" +"around us; does respiration have anything to do with this?" +"Let us study the events involved in respiration in human beings to figure" +"it out." +"Events / Steps in Respiration" +"There are no strict demarcations of events involved in the process of" +"T" +"" +"" +"" +"respiration. It is a very complex process of several biochemical and physical" +"processes. But for a general understanding on what goes on, we shall study" +"ER" +"" +"" +"" +"" +"under the following heads." +"" +"Gaseous Gaseous" +"Breathing Gas transport Cellular" +"exchange at exchange at" +"by blood Respiration" +"lungs level tissue level" +"SC" +"" +"" +"" +"" +"Air movement into Exchange of gases Transport of Exchanging of Using oxygen in" +"and out of lungs between alveoli oxygen from blood oxygen from blood cell processes to" +"and blood capillaries of alveoli into the cells and produce carbon" +"to body cells and carbon dioxide from dioxide and water," +"return of carbon cells into the blood releasing energy to" +"dioxide be used for life" +"processes" +"" +"" +"26 X Class Respiration - The energy releasing system" +" Breathing" +"In the previous classes we did experiments to find" +"" +"" +"" +"" +"A" +"out what was there in the air we breathe out." +"We had seen that in a set up with lime water, it turned" +"milky white fast as we breathe out into it as compared to" +"" +"" +"" +"" +"AN" +"a similar set up in which normal air was passed with the" +"help of a syringe or pichkari in lime water. (Experimental" +"set up to test the presence of Carbondioxide in exhaled" +"lime water" +"air). Arrange apparatus as shown in figure-3 and try to do" +"" +"" +"" +"" +"NG" +"the experiment once again to find out what happens. water" +"" +"What does this experiment indicate? fig-3: Respiratory gases" +"Which gas turns lime water milky?" +"Which gas do you think might be present in greater quantities in" +"the air we breathe out as compared to air around us?" +"LA" +"We are also aware of the fact that water vapour deposits on a mir-" +"ror if we breathe out on it." +"Where does this water vapour come from in exhaled air?" +"We shall have to study the pathway of air in our body through our" +"TE" +"" +"respiratory system and the mechanism of breathing in respiration to find" +"out how the exhaled air comes out. By “respiratory system” we usually" +"mean the passages that transport air to the lungs and to the microscopic" +"air sacs in them, called alveoli (where gases are exchanged between them" +"and blood vessels) and vice versa." +"T" +"" +"" +"Pathway of air" +"Let us observe the pathway of air from nostril to alveolus." +"ER" +"" +"" +"" +"" +"nasal cavity" +"" +"nostril" +"pharynx epiglottis" +"SC" +"" +"" +"" +"" +"larynx" +"trachea" +"" +"" +"bronchi capillaries in which O2 and" +"bronchioles CO2 exchanges occur" +"alveoli" +"lung" +"" +"fig-4: Respiratory system of man" +"" +"Free distribution by T.S. Government 2019-20 27" +" Nostrils: Air usually enters the body through the nostrils" +"" +"" +"" +"" +"A" +"Nasal cavity: Air is filtered. The moist surface of the lining of the nasal" +"cavity,, and the hairs growing from its sides, remove some" +"" +"" +"" +"" +"AN" +"of the tiny particles of dirt in the air. In addition, as the" +"inhaled air passes through the nasal cavity, its temperature" +"is brought close to that of the body, and it takes up water" +"vapour so that it becomes more moist than before." +"Pharynx: Warming and moistening goes on in this common passage" +"" +"" +"" +"" +"NG" +"of digestive and respiratory system. Epiglottis, a flap like" +"muscular valve controls movement of food and air towards" +"their respective passages." +"Larynx: This stiff box contains our vocal cords. When air passes" +"out of the lungs and over the vocal cords, it causes them" +"LA" +"to vibrate. This produces sounds on the basis of our" +"speech, song etc." +"Trachea: ind pipe channeling air to lungs. Touch your throat to" +"Wind" +"feel the tube like structure." +"TE" +"" +"Bronchus: At its lower end the trachea or the wind pipe divides into" +"two bronchi-one leading to each lung." +"Bronchioles: Each bronchi is further divided into smaller and smaller" +"branches called bronchioles." +"Alveolus: These finally terminate in clusters of air sacs called" +"T" +"" +"" +"alveoli in the lungs which are very small and numerous." +"Gaseous exchange takes place here as blood capillaries" +"take up oxygen and expel carbon dioxide." +"ER" +"" +"" +"" +"" +"Blood: Blood carries oxygen, to each and every cell of the body" +"and collects CO2 from them." +"The whole passage from nostrils to alveolus is moist and warm." +"" +"Do you know?" +"SC" +"" +"" +"" +"" +"The interior of lung is divided into millions of small chambers, thus tremendously" +"increasing the moist surface available for transfer of gases between air and blood." +"The linings of the lungs are much folded and so their total surface is enormous. If all" +"alveoli of our lungs are spread out they will cover an area of nearly 160 m2. Which is" +"equivalent to tennis court." +"" +"28 X Class Respiration - The energy releasing system" +" Think and discuss" +"" +"" +"" +"" +"A" +"What will happen if the respiratory tract is not moist?" +"Are both lungs similar in size?" +"" +"" +"" +"" +"AN" +"Why are alveoli so small and uncountable in number?" +"" +"Epiglottis and passage of air" +"Epiglottis diverts air to Epiglottis diverts food mass" +"From the nasal cavity, the air goes lungs away from opening of larynx" +"" +"" +"" +"" +"NG" +"into the pharynx. There is a tricky" +"problem here. From the pharynx there" +"are two passages, beginning with nearly" +"same opening and ending into separate" +"ones, one to the lungs and one to the" +"stomach. It is important that air goes into" +"LA" +"one and food into the other. It is also" +"important that food does not enter the" +"tube through which air goes into the" +"fig-5(a): Breathing fig-5(b): Swallowing" +"lungs. The traffic is kept properly" +"TE" +"" +"channeled by a flap like valve, the epiglottis that protects the tube to the" +"lungs, arresting entry of food. Observe the following figures and discuss" +"in your class how epiglottis works while breathing or swallowing" +"This valve is partly closed when we swallow food; it deflects food" +"down to the stomach and keeps it out of the trachea or wind pipe which is" +"T" +"" +"" +"the route to the lungs. The epiglottis opens more widely when we take a" +"breath, and air enters the lungs. Nervous regulation is important in guiding" +"the function of epiglottis and passage of food and air. Let us try to do an" +"ER" +"" +"" +"" +"" +"activity to feel what happens when we swallow food." +"Why are we advised not to talk while eating food ?" +"Activity-1" +"Activity" +"Keep your palm around an inch away from your nose, feel you are" +"SC" +"" +"" +"" +"" +"breathing out, do not remove it until you have finished the activity. Breathe" +"steadily for 1-2 minutes. Now take a piece of any fruit, chew and before" +"swallowing it keep the fingers of the other palm on your throat, now swallow" +"it." +"What did you notice? What happens to your breath as you try to" +"swallow?" +"" +"Free distribution by T.S. Government 2019-20 29" +" What is helping you to swallow without deflecting it to the wind pipe?" +"Mechanism of respiration in human beings" +"" +"" +"" +"" +"A" +"rib bones We know that breathing is the" +"process of inhaling and exhaling. The" +"" +"" +"" +"" +"AN" +"chest wall organs involved are mainly the lungs." +"muscles You can’t see your lungs, but it’s easy" +"to feel them in action. Put your hands" +"on your chest and breathe in very" +"lung deeply. You will feel your chest getting" +"" +"" +"" +"" +"NG" +"slightly bigger. Now breathe out the air," +"and feel your chest return to its regular" +"diaphragm abdomenal cavity size. You’ve just felt the power of your" +"lungs! The lungs themselves can neither" +"draw in air nor push it out. Instead, the" +"fig-6: Diagram showing lungs and diaphragm chest wall muscles and another flexible" +"LA" +"flattened muscle called diaphragm helps the lungs in moving air into and" +"out of them. See how the diaphragm works in the figure." +"What is the role of diaphragm and ribs in respiration? Are both" +"active in men and women?" +"TE" +"" +"The chest wall is made up of ribs, muscles, and the skin. The ribs are" +"attached at an angle to the spine (if you run your finger along one of your" +"ribs, you will notice that it extends downward from the spine). When we" +"inhale, the chest wall moves up and expands. This causes an increase in the" +"volume of the chest cavity." +"T" +"" +"" +"The diaphragm may be imagined as the ‘floor’ if you think of the chest" +"cavity as a “room.” When the diaphragm is relaxed when we breath out, it" +"ER" +"" +"" +"" +"" +"is in the shape of a dome with the convex side of the dome extending into" +"the chest cavity. When the diaphragm contracts during inhalation it flattens" +"out a bit or the dome moves downward. As a result, the volume of the" +"chest cavity is increased." +"When the diaphragm flattens and the volume of the chest cavity is" +"SC" +"" +"" +"" +"" +"increased, its internal pressure decreases and the air from the outside rushes" +"into the lungs. This is inspiration (inhalation)." +"fig-7: Movement Then the reverse occurs. The chest wall is lowered and moves inward," +"of rib cage" +"and the diaphragm relaxes and assumes its dome shape. These changes" +"during" +"increase the pressure on the lungs; their elastic tissue contracts and squeezes" +"inhalation," +"exhalation the air out through the nose to the external atmosphere. This is expiration" +"(exhalation)." +"30 X Class Respiration - The energy releasing system" +" Do you know?" +"Our lungs are spongy in nature. They are not of the same size. The lung towards left" +"" +"" +"" +"" +"A" +"is slightly smaller making space for your heart! Lungs are protected by two membranes" +"called pleura. A fluid filled between these membranes protects the lungs from injury" +"" +"" +"" +"" +"AN" +"and also aid in the expansion of the spongy and elastic lung muscle, as they slide one" +"over the other." +"You must have noticed that your own breathing is slow and shallow" +"when you are at rest. It is deeper and faster when you exercise hard. Indeed," +"patterns of breathing show a great range, for they are coordinated with" +"" +"" +"" +"" +"NG" +"moment-by-moment needs of the body for supply of oxygen and removal" +"of carbon dioxide." +"What other situations affect your breathing?" +"It has been found that all movements of breathing stop at once when" +"the nerves leading from the brain to the respiratory muscles are cut." +"LA" +"What can be concluded from this?" +"What happens during the process of breathing?" +"Which gas needs to be removed from our body during exhalation?" +"Where does the extra amount of gas come from?" +"TE" +"" +"What is the composition of inhaled air?" +"When exhaled air is compared with inhaled air, is there any differ-" +"ence in composition?" +"Gaseous Exchange (alveoli to capillaries)" +"Gaseous exchange takes place within the lungs by diffusion from the" +"T" +"" +"" +"" +"alveoli to blood capillaries and vice versa. The carbondioxide in the blood" +"is exchanged for oxygen in the alveoli. These tiny air sacs in the lungs are" +"ER" +"" +"" +"" +"" +"numerous and only one cell thick. They are surrounded by capillaries that" +"are also only one cell thick. Blood, dark" +"red in colour flows from the heart" +"bronchiole" +"through these capillaries and collects" +"oxygen from the alveoli. At the same Alveolar cavity" +"SC" +"" +"" +"" +"" +"carbondioxide" +"time, carbondioxide passes out of the" +"capillaries and into the alveoli. When oxygen red blood corpuscles" +"blood capillary" +"we breathe out, we get rid of this" +"carbondioxide. The bright red, oxygen-" +"rich blood is returned to the heart and" +"fig-8: Diagram of Alveolus with pulmonary" +"pumped out to all parts of the body." +"capillary" +"" +"Free distribution by T.S. Government 2019-20 31" +" As a result of gaseous exchange, the composition of inhaled and" +"exhaled air is different. See the table given below. Approximate values are" +"given in the table" +"" +"" +"" +"" +"A" +"Gas % in inhaled air % in exhaled air" +"" +"" +"" +"" +"AN" +"Oxygen 21 16" +"Carbondioxide 0.03 4.4" +"Nitrogen 78 78" +"" +"Why does the amount of Oxygen vary between exhaled and inhaled" +"" +"" +"" +"" +"NG" +"air?" +"What has raised the percentage of carbon dioxide in exhaled air?" +"" +"Do you know?" +"The total lung capacity of human being is nearly 5800ml. Normally at rest who" +"LA" +"inhale or exhale approximately 500ml of air. 1200ml of air remains in lungs after" +"complete exhalation." +"Recall the activity of lung capacity performed by you in class VII" +"in the chapter ‘Respiration in Organisms’." +"TE" +"" +"Transportation of gases" +"We know that air is a mixture of gases, that fills the lungs and the" +"alveoli when that enters our body. The relative amount of different gases" +"in air and their combining capacity with haemoglobin and other substances" +"in blood determine their transport via blood in the body." +"T" +"" +"" +"" +"When oxygen present in the air is within normal limits (around 21%)" +"then almost all of it is carried in the blood by binding to haemoglobin, a" +"ER" +"" +"" +"" +"" +"protein (quite like chlorophyll, the only major difference being it has iron" +"in place of magnesium as in chlorophyll) present in the red blood cells. As" +"oxygen is diffused in the blood, it rapidly combines with the haemoglobin" +"to form oxyhaemoglobin. Not only haemoglobin can combine with oxygen," +"but the reverse can also happen to yield a molecule of haemoglobin and" +"SC" +"" +"" +"" +"" +"oxygen." +"Carbon dioxide is usually transported as bicarbonate, while some" +"amount of it combines with haemoglobin and rest is dissolved in blood" +"plasma. Study the following equation for better understanding." +"Hb + 4O2 Hb(O2)4 (in lungs)" +"" +"Hb(O2)4 Hb + 4O2 (in tissues)" +"" +"32 X Class Respiration - The energy releasing system" +" Do you know?" +"If haemoglobin is exposed to air at sea" +"" +"" +"" +"" +"A" +"level, nearly every molecule combines with" +"oxygen to form oxyhaemoglobin. At a height" +"" +"" +"" +"" +"AN" +"of 13 km (about 8 miles) above sea level, the" +"concentration of oxygen is much lower about" +"one fifth at sea level." +"fig-9: Mountaneer" +"Under these conditions only about half as many molecules of oxygen combine" +"" +"" +"" +"" +"NG" +"with haemoglobin to form oxyhaemoglobin. This is important, because blood cannot" +"carry enough oxygen to the tissues if haemoglobin is combined with few oxygen" +"molecules. In fact, human life is impossible at such an altitude without a supplementary" +"supply of oxygen. Provision for such a supply is built into modern aircraft, which" +"have pressurized cabins that maintain an enriched air supply. When we go deep into" +"LA" +"the sea we will face another type of problems." +"Gaseous exchange (capillaries to cells and back)" +"In the capillaries over the tissues, haemoglobin meets a very different environment." +"The tissue cells are continuously using oxygen, hence, the concentration of oxygen is quite" +"TE" +"" +"low in them. It might be only one third of that in the lungs. As the concentration of oxygen" +"is so low, oxyhaemoglobin releases the oxygen molecule that enters the cells. In the" +"reactions that occur within cells in our bodies, carbon dioxide and water are produced and" +"energy is released to be used up for different purposes." +"Cellular respiration" +"The term cellular respiration refers to the pathway by which cells release energy by" +"T" +"" +"" +"" +"breaking the chemical bonds of glucose molecules. Thus cellular respiration is the essential" +"processes of life. So living cells must carry out cellular respiration. It can be in the presence" +"ER" +"" +"" +"" +"" +"of oxygen that is ‘aerobic respiration’, or in the absence of oxygen as in bacterial respiration" +"by anaerobic method which is called fermentation. The substances become sour because" +"of ethyl alchohol or lactic acid is produced in this process. In Animals the anaerobic" +"respiration leads to formation of lactic acid from glucose. In anaerobic repiration few ATP" +"molecules are produced. Cellular respiration in prokaryotic cells like that of bacteria occurs" +"within the cytoplasm. In eukaryotic cells cytoplasm and mitochondria are the sites of the" +"SC" +"" +"" +"" +"" +"reactions. The produced energy is stored in mitochondria in the form of ATP. That is why" +"mitochondria are called “power houses of the cell”." +"The exact chemical details of the breakdown of sugar or other foods within a living cell" +"does not take place as a single reaction, but occurs in a series of small steps." +"How does this affect the energy release? As the change in the chemical nature of the" +"molecule from one stage to the next is slight, in any step small amount of energy is released." +"The complete breakdown of a sugar molecule with the release of all its available energy" +"Free distribution by T.S. Government 2019-20 33" +" involves a series of different chemical reactions." +"outer membrane" +"inner membrane" +"From the breakdown of glucose the energy is" +"released and stored up in a special compound, known" +"" +"" +"" +"" +"A" +"cristae as ATP (adenosine triphosphate). It is a small parcel of" +"matrix chemical energy. The energy currency of these cells" +"" +"" +"" +"" +"AN" +"is ATP an energy rich compound that is capable of" +"supplying energy wherever needed within the cell. Each" +"ATP molecule gives 7200 calories of energy. This" +"energy is stored in the form of phosphate bonds. If the" +"fig-10: Mitochondria" +"bond is broken the stored energy is released." +"" +"" +"" +"" +"NG" +"Do cells of alveoli or lungs also require oxygen to carry out cellular" +"respiration? Why/Why not?" +"In short, at cellular level we could have the following pathways starting" +"with glucose (It is one example, remember that there are other components" +"of food as well)." +"LA" +"Lactic acid + Energy" +"Absence or low" +"Eg: Lactobocilus" +"amount of oxygen" +"(anaerobic respiraton" +"and fermentation) Ethanol + CO2+ Energy" +"TE" +"" +"Glucose Pyruvate Eg: Yeast" +"(3 carbon compound)" +"+ Energy" +"(Glycolysis)" +"Presence of Oxygen CO2 + H2O + Energy" +"(aerobic respiration) Eg: Plants and animals" +"T" +"" +"" +"Glucose is the most commonly used sugar for deriving energy in plants," +"animals and in microorganisms. In all these organisms the glucose is" +"ER" +"" +"" +"" +"" +"oxidized in two stages. In the first stage it is converted into two molecules" +"of pyruvic acid. In the second stage if oxygen is available pyruvic acid is" +"oxidized to CO2, water and large amount of energy is released." +"If oxygen is inadequate or not utilised pyruvic acid is converted into" +"either ethanol or lactic acid and very little amount of energy (nearly one" +"SC" +"" +"" +"" +"" +"tenth of that is produced with adequate amount of oxygen) is released." +"Can energy be released without oxygen?" +"After undergoing strenous exercise, we feel pain in muscles. Does" +"adequate oxygen reach the muscles?" +"What is being formed in the muscles?" +"" +"34 X Class Respiration - The energy releasing system" +" When you sprint a hundred yards, you do a considerable" +"amount of muscular work. But you do not start a race by" +"standing on the track and panting for a few minutes to stoke up" +"" +"" +"" +"" +"A" +"with oxygen first. In fact you can run the race with very little" +"extra breathing. The fastest sprinters do not breathe at all when" +"" +"" +"" +"" +"AN" +"running a hundred yards. After you have reached the destiny," +"however, you feel very different. Depending on your state of" +"training, and on how hard you ran, you will pant for some" +"minutes after the race, until your breathing gradually returns" +"to normal." +"" +"" +"" +"" +"NG" +"These facts could be linked up with what we have learned fig-11: Athlete" +"so far about ATP. It might be that the race was run on the energy (Strenous excercise)" +"produced when the ATP already present in your muscles was being converted" +"to ADP. Unfortunately this pleasantly simple idea is inadequate, because" +"we only carry sufficient ATP in a muscle to last for about half a second" +"LA" +"when doing vigorous exercise. There must be some other explanation for" +"the way in which we can produce energy first and then use up oxygen later." +"One approach in the study of this problem was to analyze the blood of" +"a person during and after exercise. For obvious reasons the athlete taking" +"part in the experiment had to stay still where the apparatus was. He pedaled" +"TE" +"" +"a stationary bicycle, or ran on a tread mill (belt moving as fast backwards" +"as the athlete moved forwards). Some results are shown in the graph." +"Vigorous exercise lasted for nine minutes (shown by the bar at the base of" +"the diagram) and regular blood samples were taken and analyzed. One" +"particular compound in the" +"T" +"" +"" +"blood, lactic acid, was found to" +"Concentration of Lactic Acid in Blood" +"" +"" +"" +"" +"vary greatly in its concentration" +"ER" +"" +"" +"" +"" +"as you can see from the graph." +"Observe the graph of lactic" +"acid accumulation in the" +"mg/cm 3" +"" +"" +"" +"" +"muscles of an athelete and" +"answer the following questions." +"SC" +"" +"" +"" +"" +"(Graph showing varying" +"amount of lactic acid in the" +"muscles)" +"x - axis = Time in minutes" +"Time in minutes" +"y - axis = Concentration of" +"lactic acid in blood mg/cm3 Graph showing effects of vigorous excercise on the" +"concentration of lactic acid in blood." +"Free distribution by T.S. Government 2019-20 35" +" a. What was the concentration of lactic acid in the blood to start with?" +"b. What was the greatest concentration reached during the experiment?" +"c. If the trend between points C and D were to continue at the same rate," +"" +"" +"" +"" +"A" +"how long might it take for the original lactic acid level to be reached" +"again? (Hint: extend the line CD until it reaches the starting value.)" +"" +"" +"" +"" +"AN" +"d. What does high level of lactic acid indicate about the condition of" +"respiration?" +"Accumulation of lactic acid results in muscular pain. If we take walk," +"brisk walk, slow jogging, running for same distance we feel that there an" +"increase in pain levels this is because of lactic acid accumulation." +"" +"" +"" +"" +"NG" +"It seems as if the lactic acid was being produced rapidly by the active" +"muscles, and then only gradually removed from the blood after exercise." +"What is surprising is that the athlete needs a great length of time to recover." +"The simplest explanation we can produce at-this stage is that the sugar in" +"the working muscles was being changed to lactic acid. The energy stored" +"LA" +"in lactic acid molecules is less than that in sugar molecules, and if the acid" +"comes from the sugar then the energy released could be used to rebuild" +"ATP from ADP and phosphate." +"During a 100 m race a well-trained athlete can hold his breath all the" +"TE" +"" +"time it is not until afterwards that he pants. In this case, the muscles are" +"using the energy released during the anaerobic breakdown of glucose. It is" +"not until afterwards that the athlete obtains the oxygen needed in order to" +"remove the lactic acid. Therefore, when we under-take strenuous exercise" +"we build up what is called an oxygen debt which has to be repaid later. In a" +"longer race athletes have to breathe all the time, so some lactic acid is" +"T" +"" +"" +"" +"removed while they are running, and they can go on for longer before" +"becoming exhausted. The presence of lactic acid in the blood is the main" +"ER" +"" +"" +"" +"" +"cause of muscle fatigue, but if the body is rested for long enough the" +"tiredness goes." +"Anaerobic respiration" +"We have found that living things produce carbon dioxide and give out" +"SC" +"" +"" +"" +"" +"energy. If these processes are caused by an oxidation process, what happens" +"if the oxygen supply is cut off? If human muscles can go on releasing" +"energy when they are short of oxygen, what can cells of other living" +"organisms do?" +"Let us find out by doing some experiments." +"" +"" +"" +"36 X Class Respiration - The energy releasing system" +" Lab Activity" +"" +"" +"" +"" +"A" +"Some experiments with yeast" +"To test this idea we can see whether it is possible to detect any rise in" +"temperature and the production of carbon dioxide, when living organisms" +"" +"" +"" +"" +"AN" +"are kept away from a supply of oxygen." +"Yeast grows rapidly if it is supplied with thermometer" +"glucose in solution. Indeed, wild yeasts are" +"normally found growing on the skins of fruits" +"like grapes and apples, from which they derive" +"" +"" +"" +"" +"NG" +"their food supplies. Our immediate problem is" +"to remove the oxygen from the glucose" +"solution and yeast." +"Arrange the apparatus as shown in fig. 12 liquid paraffin" +"lime water" +"1. You can remove dissolved oxygen from glu-" +"cose solution by heating it for a minute, and yeast in boiled and" +"LA cooled glucose" +"then cooling it without shaking. Now put in" +"some yeast; the supply of oxygen from the" +"fig-12: Testing for production of heat and" +"air can be cut off by pouring one centimetre" +"CO2 under anaerobic respiration" +"layer of liquid paraffin on to the mixture." +"TE" +"" +"2. If you wish to check that the oxygen has been removed from the mix-" +"ture, add a few drops of diazine green (Janus Green B) solution to the" +"yeast suspension before you pour the liquid paraffin (wax) over it." +"This blue dye turns pink when oxygen is in short supply around it." +"3. Arrange for any gas produced by the yeast to escape through a wash" +"bottle containing bicarbonate/indicator solution (or lime water)." +"During the process of anaerobic respiration some amount of" +"T" +"" +"" +"" +"carbondioxide is released. The released carbondioxide passes through" +"the tube and turns lime water milky. We can observe the change in the" +"ER" +"" +"" +"" +"" +"temperature also during this process out for yourself. You may prefer to" +"carry out the ‘carbon dioxide production’ part of the experiment on a" +"smaller scale, using test tubes. If you do, then warm them to about 37o C in" +"order to speed up the test." +"What happens when a baker prepares a dough by mixing yeast in it?" +"SC" +"" +"" +"" +"" +"Fermentation" +"Let us recall maida dough and yeast powder activity that you performed" +"in class VIII in the chapter ‘The story of microorganisms’. Why volume of" +"the dough has increased? Which gas released in that reaction?" +"If yeast and sugar solution are left to stand without oxygen for some" +"days, they develop a characteristic smell, caused by production of new" +"compound called ethanol, which has been manufactured by the yeast from" +"Free distribution by T.S. Government 2019-20 37" +" the sugar. The same type of smell you can notice from preserved idly," +"dosa dough at your home. But not in refrigirator. The ethanol can be" +"separated from the yeast-glucose mixture by the process of fractional" +"" +"" +"" +"" +"A" +"distillation since ethanol boils at a lower temperature (70°C) than the sugar" +"solution. Collect information about fractional distillation with the help" +"" +"" +"" +"" +"AN" +"your teacher." +"Quite like aerobic respiration this is a process of producing energy" +"when there is no supply of oxygen." +"Respiration is an energy releasing pathway, do you agree? Justify" +"your answer." +"" +"" +"" +"" +"NG" +"Respiration versus combustion" +"Lavoisier around the late 18thcentury, through a series of carefully" +"performed experiments, came to the opinion that respiration was a process" +"like combustion. He wrote in a compilation in 1783, “respiration is a" +"LA" +"combustion process. It is a very slow process and here oxygen is not only" +"combines with carbon but also with hydrogen.” Robinson also stated that" +"respiration is a type of combustion and combustion is the source of heat" +"in animals." +"TE" +"" +"Activity-2" +"Activity-2" +"Observing changes during combustion of glucose" +"Arrange apparatus as shown in the figure and heat it over a flame." +"Does it melt? What happens if you heat for somemore time?" +"When glucose burns, carbon dioxide and water" +"T" +"" +"" +"" +"glucose are produced and energy is released as heat." +"test tube" +"We know that combustion of glucose gives us" +"ER" +"" +"" +"" +"" +"carbon dioxide, water and energy while from the" +"heat delivery" +"tube respiratory equation we get the same products. But" +"essentially the processes must differ due to" +"following reasons." +"1. Glucose must be burnt at high temperature in" +"SC" +"" +"" +"" +"" +"the laboratory to liberate energy, if it happened" +"in our cells,all cells would be burnt." +"lime water 2. Once glucose starts burning we can’t stop the" +"process easily, but living cells are able to exer-" +"fig-13: CO2 - a by product of energy cise control over the sort of burning of glucose" +"release in the presence of oxygen." +"" +"38 X Class Respiration - The energy releasing system" +" 3. Water normally stops combustion from taking place while cells con-" +"tain a lot of water and respiration still goes on." +"What can you conclude from this?" +"" +"" +"" +"" +"A" +"Heat production by living organisms" +"Heat production was a feature of burning glucose or sugar as you" +"" +"" +"" +"" +"AN" +"observed earlier. Living animals and plants usually produce energy in the" +"form of heat." +"We feel warm when we wear sweater in winter season. We know that" +"sweater prevents loss of heat energy produced by the body. Does this" +"" +"" +"" +"" +"NG" +"suggest any way in which our bodies lose heat to the surroundings?" +"What are the other ways in which our body loses heat?" +"Heat is constantly lost from the body surface thus it must be" +"continuously generated within our bodies to replace what has been lost to" +"keep the body temperature constant." +"Is the rate of heat production always the same?" +"LA" +"In the course of vigorous activity, a greater amount of heat is generated." +"We know that we feel hot after some form of strenuous exercise such as" +"running." +"During cellular respiration energy is released. Some part of energy is" +"TE" +"" +"stored in the form of ATP. Some part of energy is utilised in our day to day" +"life activities. And the excess amount of energy is released in the form of" +"heat. But in case of vigorous activity like running we need more amount of" +"energy. For this the rate of respiration is increased. So heat is also released" +"in excess quantity. That’s why we feel warm. If the oxygen is not sufficient" +"T" +"" +"" +"during vigorous exersise muscles start anaerobic respiration. Hence, lactic" +"acid is formed. We know that accumulation of lactic acid causes pain in" +"ER" +"" +"" +"" +"" +"muscle. We reach normal position after some rest. Deep breathing helps" +"us to restore energy in our body. Refer in annexure about Yoga Asanas." +"Evolution in gases exchanging system" +"Exchange of gases is a common life process in all living organisms," +"but it is not same in all. Single celled organisms Amoeba or multicellular" +"SC" +"" +"" +"" +"" +"organisms like Hydra and Planarians roundworms and earthworms obtain" +"oxygen and expel carbon dioxide directly from the body by the process of" +"diffusion. In other multicellular animals special organs are evolved. Animals" +"either terrestrial or aquatic adopted to different types of respiration and" +"possess different types of respiratory organs mostly depending on the" +"habitat in which they live. Body size, availability of water and the type of" +"" +"Free distribution by T.S. Government 2019-20 39" +" their circulatory system are some of the reasons for the animals to develop" +"different types of respiratory organs." +"There is tracheal respiratory system in insects like cockroach," +"" +"" +"" +"" +"A" +"grasshopper etc. Tracheal respiratory system consists of series of tubes" +"called trachea. This is divided into fine branches called tracheoles which" +"" +"" +"" +"" +"AN" +"carry air directly to the cells in the tissues." +"Some aquatic animals like fishes have developed special organs for" +"respiration which are known as gills or branchiae. Blood supplied to gills" +"through capillaries which have thin walls where gases are exchanged. This" +"is called branchial respiration. Fish keeps its mouth open and lowers the" +"" +"" +"" +"" +"NG" +"floor of the oral cavity. As a result water from outside will be drawn into" +"the oral cavity. Now the mouth is closed and the floor of the oral cavity is" +"raised. Water is pushed into the pharynx and is forced to gill pouches" +"through internal branchial apertures. Gill lamellae are bathed with water" +"and gaseous exchange takes place." +"Respiration through skin is called cutaneous respiration. Frog an" +"LA" +"amphibian can respire through cutaneous and pulmonary respiration" +"(through lungs) processes as well as Bucco-Pharyngeal Cavity. Terrestrial" +"animals like reptiles, birds and mammals, respire through lungs. Ask your" +"teacher how crocodiles and dolphins respire?" +"TE" +"" +"Respiration in Plants" +"You already know about stomata in leaf where" +"gaseous exchange takes place in plants. There are" +"other areas on the plant body as well through which" +"water film" +"gaseous exchange take place like surface of roots," +"T" +"" +"" +"" +"air spaces lenticels on stem etc. (Fig showing stomata and" +"stomata" +"stomata lenticels). Some plants have specialized structures" +"ER" +"" +"" +"" +"" +"like breathing roots of mangrove plants as well as" +"fig-14: Leaf as a respiratory organ the tissue in orchids that produces oxygen is also" +"required by plants to produce energy and carbon" +"dioxide is released. But CO2 is required elsewhere" +"in the plants try to identify them." +"SC" +"" +"" +"" +"" +"Conduction within the plant" +"The stomatal openings lead to a series of spaces" +"between the cells inside the plant. Which form a" +"continuous network all over the plant. The spaces" +"are very large in the leaves, much smaller in other" +"parts of the plant. The air spaces are lined with water" +"fig-15: Lenticels on stem where the oxygen is dissolved in this and passes" +"40 X Class Respiration - The energy releasing system" +" through the porous cell walls into the cytoplasm. Here the sugar is broken" +"down into carbon dioxide and water with the liberation of the energy. The" +"carbon dioxide passes out into the air spaces by a similar method." +"" +"" +"" +"" +"A" +"The whole system works by diffusion; as the oxygen is used up by the" +"cells a gradient develops between the cells and the air in the spaces." +"" +"" +"" +"" +"AN" +"Similarly between the air in the spaces and the air outside the stomata and" +"lenticels, so oxygen passes in. In the same way, as more carbon dioxide is" +"released by the cells a gradient occurs in the reverse direction and it passes" +"out to the environment." +"Aeration of roots" +"" +"" +"" +"" +"NG" +"Most plants can aerate their roots by taking in the" +"oxygen through the lenticels or through the surface of" +"their root hairs (as their walls are very thin). They obtain" +"oxygen from the air spaces existing between the soil" +"particles. But, plants which grow in very wet places," +"LA" +"such as ponds or marshy soils, are unable to obtain" +"oxygen. They are adapted to these water-logged fig-16: Aerial/respiratory roots" +"conditions by having much larger air spaces which connect the stems with" +"the aerial roots, making diffusion from the upper parts much more efficient." +"TE" +"" +"The most usual adaptation is to have a hollow stem. Next time when" +"you are by a pond or marsh cut the stems of some of the plants which are" +"growing there and see how many are hollow compared with a similar" +"number of species of plants growing in normal soil. The problem of air" +"transport is more difficult for trees and not many survive with their roots" +"permanently in water. An exception is the mangrove tree of the tropics" +"T" +"" +"" +"" +"which have aerial roots above the soil surface and takes in oxygen through" +"these roots." +"ER" +"" +"" +"" +"" +"To know more about respiration in plants we should perform the" +"following activities." +"Activity-3" +"Activity" +"Take a handful of moong or Bengalgram seeds." +"SC" +"" +"" +"" +"" +"Soak the seeds in water a day before to perform your" +"experiment. Keep these soaked seeds in a cloth pouch sprouted seeds" +"" +"and tie with a string tightly. Keep the cloth pouch in a" +"corner of your class room. Next day collect the sprouts/" +"germinated seeds from the pouch, keep it in a glass beaker with" +"lime water" +"bottle/plastic bottle(around 200 ml capacity). Take a fig-17: Evolved CO2 in respiration" +"" +"Free distribution by T.S. Government 2019-20 41" +" small beaker, fill three fourth with lime water. Insert it in the beaker" +"carefully. Close the plastic bottle tightly. Make a similar set with" +"unsprouted seeds. Keep this set undisturbed for one or two days. During" +"" +"" +"" +"" +"A" +"this time observe the colour of lime water in both the sets. In which set" +"does the colour change faster? Why?" +"" +"" +"" +"" +"AN" +"Activity-4" +"Take sprouts which were prepared for above activity" +"thermometer" +"in a thermosflask. Remove the lid and prepare a cork" +"(with thermocol, or rubber or any other material) through" +"which you can bore a hole to insert a thermometer. Take" +"" +"" +"" +"" +"NG" +"care that the bulb of the thermometer should dip in the" +"sprouts. Close the flask with this tight fitting cork. Record" +"the temperature for every two hours. You are advised to" +"Thermosflask" +"do this for at least 24 hours." +"Make a graph by using your observations." +"Is there any increase in temperature?" +"germinating seeds" +"LA Does the temperature increase steadily or does it" +"abruptly increase at a time of the day?" +"Where does the heat come from?" +"fig-18: Heat evolved during" +"respiration Photosynthesis versus Respiration" +"TE" +"" +"Plants carry out photosynthesis, which means that they produce their" +"own food from atmospheric CO2 using light energy from the sun. This" +"process is a complex series of steps involving the conversion of light" +"energy into chemical energy, which is then used to synthesize sugars from" +"carbon dioxide. This is a process of synthesis or an anabolic process which" +"occurs in the chloroplasts." +"T" +"" +"" +"The equation below summarizes the photosynthetic process" +"Light energy" +"CO2+ H2O (CH2O) n+ O2" +"ER" +"" +"" +"" +"" +"Chlorophyll Sugar" +"After balancing the equation" +"Light energy" +"6CO2+ 12H2O C6H12O6 + 6H2O + 6O2" +"Chlorophyll Sugar" +"SC" +"" +"" +"" +"" +"Once produced, the sugars can then be used for the process of" +"respiration to provide energy to run all life processes." +"Respiration as we know is not just the exchange of gases. It is the" +"process of breakdown of complex food molecules or a catabolic process" +"to produce chemical or potential energy." +"This can be summarized by the equation" +"(CH2O)n+ O2 CO2+ H2O + Energy" +"42 X Class Respiration - The energy releasing system" +" C6H12O6 + 6O2 6CO2 + 6H2O + Energy" +"Photosynthesis and respiration appear to be opposing reactions, but" +"both have very different biochemical pathways and are essential for a plant’s" +"" +"" +"" +"" +"A" +"metabolism." +"Photosynthesis takes place in the chloroplast to produce sugars, starch" +"" +"" +"" +"" +"AN" +"and other carbohydrates for the plant’s metabolic needs. Cellular respiration" +"occurs in mitochondria where these carbohydrates are “burned” to produce" +"chemical energy to function at the cellular level. During day time, the rate" +"of photosynthesis is usually higher than that of respiration while at night it" +"is just reverse in most plants. Temperature, humidity, light intensity etc." +"" +"" +"" +"" +"NG" +"seem to affect the ratio of photosynthesis and respiration in plants." +"" +"" +"Key words" +"Aerobic respiration, Anaerobic respiration, Alveoli, Pharynx, Trachea, Bronchi," +"LA" +"Bronchioles, Epiglottis, Anabolicprocess, Catabolicprocess, Aerial roots, Lenticels," +"Fermentation, energy currency." +"" +"" +"" +"What we have learnt" +"TE" +"" +"By “respiratory system” we usually mean the passages that transport air to the lungs and to the" +"microscopic air sacs in them, called alveoli (where gases are exchanged) and vice versa." +"The term ‘respiration’ refers to the whole chain of processes from the inhalation of air to the use of" +"oxygen in the cells." +"T" +"" +"" +"" +"Lavoisier found that the air that we breathe out precipitated lime water" +"Air passes from nostrils to nasal cavity to pharynx, larynx, trachea, and bronchi, bronchioles to" +"ER" +"" +"" +"" +"" +"alveoli and blood and back through the same route." +"Gas exchange in the lungs takes place in the tiny air sacs called alveoli in the lungs. The lungs have" +"millions of alveoli and each lies in contact with capillaries." +"Diaphragm is a muscular tissue present at the floor of the chest cavity." +"SC" +"" +"" +"" +"" +"During inspiration (inhalation) the volume of the chest cavity is increased as the diaphragm contracts" +"and dome flattens out, its internal pressure decreases and the air from the outside rushes into the" +"lungs." +"During expiration, the chest wall is lowered and moves inward, and the diaphragm relaxes and" +"assumes its dome shape. These changes increase the pressure on the lungs; their elastic tissue" +"contracts and squeezes the air out through the nose to the external atmosphere." +"Air is filtered in the nasal cavity and the whole length of the trachea." +"Free distribution by T.S. Government 2019-20 43" +" The moist surface of the lining of the nasal cavity, and the hairs growing from its sides, remove some" +"of the tiny particles of dirt in the air. In addition, as the inhaled air passes through the nasal cavity, its" +"temperature is brought close to that of the body, and it takes up water vapour. So that it becomes" +"" +"" +"" +"" +"A" +"more moist than before." +"Pharynx is a common passage of digestive and respiratory system. Epiglottis, a flap like muscular" +"" +"" +"" +"" +"AN" +"valve controls movement of air and food towards their respective passages." +"Larynx is a stiff box like structure containing our vocal cords. When air passes out of the lungs and" +"over the vocal cords, it causes them to vibrate. This produces sounds on the basis of our speech," +"song etc." +"" +"" +"" +"" +"NG" +"Trachea is the wind pipe channeling air to lungs." +"At its lower end the trachea or the wind pipe divides into two bronchi-one leading to each lung." +"The bronchi divide into smaller and smaller branches called bronchioles." +"These finally terminate in clusters of air sacs called alveolus in the lungs which are very small and" +"numerous. Gaseous exchange takes place here as blood capillaries take up oxygen and expel" +"carbon dioxide here." +"LA" +"Aerobic respiration occurs in adequate supply of air producing a lot of energy, carbon dioxide and" +"water." +"Anaerobic respiration and fermentation occurs in inadequate supply or absence of oxygen to produce" +"TE" +"" +"energy." +"Cells may resort to the breakdown of 3 carbon compound, pyruvate, aerobically or anaerobically" +"depending upon the availability of oxygen. Usually in multicellular organisms cells fail to carry on" +"the process of anaerobic respiration for long." +"Respiration is not essentially a process of combustion differ due to following reasons" +"- Glucose must be burnt at high temperature in the laboratory to liberate energy, if it happened in" +"T" +"" +"" +"" +"our cells, all cells would be burnt." +"- Once glucose starts burning we can’t stop the process easily, but living cells are able to exercise" +"ER" +"" +"" +"" +"" +"control over the sort of burning of glucose in the presence of oxygen." +"- Water normally stops combustion from taking place while cells contain a lot of water and" +"respiration still goes on." +"Photosynthesis and respiration appear to be opposing reactions, but both have very different" +"SC" +"" +"" +"" +"" +"biochemical pathways and are essential for a plant’s metabolism." +"Photosynthesis takes place in the chloroplast to produce sugars, starches and other carbohydrates" +"for the plant’s metabolic needs." +"Cellular respiration occurs in mitochondria where mainly these carbohydrates are “burned” to" +"produce chemical energy to do work at the cellular level." +"" +"" +"" +"44 X Class Respiration - The energy releasing system" +" Improve your learning" +"" +"" +"" +"" +"A" +"1. Distinguish between (AS1)" +"a) inspiration and expiration b) aerobic and anaerobic respiration" +"" +"" +"" +"" +"AN" +"c) respiration and combustion d) photosynthesis and respiration" +"2. State two similarities between aerobic and anaerobic respiration.(AS1)" +"3. Food sometimes enters the wind pipe and causes choking. How does it happen?(AS1)" +"4. Why does the rate of breathing increase while walking uphill at a normal pace in the mountains?" +"" +"" +"" +"" +"NG" +"Give two reasons.(AS1)" +"5. Air leaves the tiny sacs in the lungs to pass into capillaries. What modification is needed in the" +"statement?(AS1)" +"6. Plants photosynthesize during daytime and respire during the night. Do you agree to this statement?" +"Why? Why not?(AS1)" +"LA" +"7. Why does a deep sea diver and mountainair carry oxygen cylinder on her back?(AS1)" +"8. How are alveoli designed to maximize the exchange of gases?(AS1)" +"9. Where will the release of energy from glucose in respiration take place? Mala writes lungs while" +"Raziya writes muscles. Who is correct and why?(AS1)" +"10. What is the role of epiglottis and diaphragm in respiration?(AS1)" +"TE" +"" +"11. How does gaseous exchange takes place at blood level (or) cellular level?(AS1)" +"12. Explain the mechanism of gaseous exchange at branchiole level.(AS1)" +"13. After a vigorous excercise or work we feel pain in muscles. What is the relationship between pain" +"and respiration?(AS1)" +"14. Raju said stem also respire along with leaves in plants. Can you support this statement? Give your" +"T" +"" +"" +"" +"reasons.(AS1)" +"15. What happen if diaphragm is not there in the body?(AS2)" +"ER" +"" +"" +"" +"" +"16. If you have a chance to meet pulmonologist what questions are you going to ask about pulmonory" +"respiration?(AS2)" +"17. What procedure do you follow to understand anaerobic respiration in your school laboratory?(AS3)" +"18. What are your observations in combustion of sugar activity?(AS3)" +"SC" +"" +"" +"" +"" +"19. Collect information about cutaneous respiration in frog. Prepare a note and display them in your" +"classroom.(AS4)" +"20. Collect information about respiratory diseases (because of pollution, tobacco) and discuss with" +"your classmates.(AS4)" +"21. What is the pathway taken by air in the respiratory system? Illustrate with a labelled diagram.(AS5)" +"22. Draw a block diagram showing events in respiration. Write what you understood about cellular" +"respiration.(AS5)" +"Free distribution by T.S. Government 2019-20 45" +" 23. How you appreciate the mechanism of respiration in our body?(AS6)" +"24. Prepare an article on anaerobic respiration to present school symposium.(AS7)" +"" +"" +"" +"" +"A" +"25. Prepare a cartoon on discussion between haemoglobin and chlorophyll about respiration.(AS7)" +"" +"" +"Fill in the blanks" +"" +"" +"" +"" +"AN" +"1. Exhaled air contains _________ and _________." +"2. A flap like muscular valve controls movement of air and food is ___________." +"" +"" +"" +"" +"NG" +"3. Energy currency of the cell is called _____________." +"4. Lenticels are the respiratory organs exists in __________ part of plant." +"5. Mangroove trees respire with their ____________." +"" +"" +"Choose the correct answer" +"LA" +"6. We will find vocal cords in ( )" +"A) larynx B) pharynx C) nasal cavity D) trachea" +"TE" +"" +"7. Cluster of air sacs in lungs are called ( )" +"A) alveoli B) bronchi C) bronchioles D) air spaces" +"8. Which of the following is correct ( )" +"i) the diaphragm contracts - volume of chest cavity increased" +"T" +"" +"" +"ii) the diaphragm contracts - volume of chest cavity decreased" +"iii) the diaphragm expands - volume of chest cavity increased" +"ER" +"" +"" +"" +"" +"iv) the diaphragm expands - volume of chest cavity decreased" +"A) i B) i & ii C) ii & iii D) iv" +"9. Respiration is a catabolic process because of ( )" +"A) breakdown of complex food molecules B) conversion of light energy" +"SC" +"" +"" +"" +"" +"C) synthesis of chemical energy D) energy storage" +"10. Energy is stored in ( )" +"A) nucleus B) mitochondria C) ribosomes D) cell wall" +"" +"" +"" +"" +"46 X Class Respiration - The energy releasing system" +" Annexure" +"" +"" +"" +"" +"A" +"Pranayama - The art of breathing" +"It is wonder to know that only human beings" +"" +"" +"" +"" +"AN" +"have to learn how to breath. Our lungs are divided" +"into lobes. At each breath we will inhale or exhale" +"only 500ml of air. Where as our lung capacity is" +"approximately 5800ml. So most of the time" +"breathing takes place in the upper lobes only. This" +"" +"" +"" +"" +"NG" +"means we are not using our lungs to their fullest" +"capacity. Even after complete expiration" +"approximately 1200ml of air remains in our" +"lungs. So we can make use of 4600ml of lung" +"capacity for breathing. Think what changes are" +"required to inhale that much air." +"LA" +"The Indian ayurvedic physician. Patanjali developed a scientific" +"breathing practice called Yogabhyasa." +"Yogabhyasa. Maharshi Patanjali proposed a" +"theory called Astanga yoga. He was introduced 195 yogic principles in" +"TE" +"" +"eight divisions. 1. Yama (Social disipline), 2. Niyama (Individual" +"discipline), 3. Asana (Body posture), 4. Pranayama (Expansion of vital" +"energy), 5. Prathyahara (With drawal of senses), 6. Dharana" +"(Consentration), 7. Dhyana (Meditation), 8. Samadi (Self realisation)." +"The art of breathing in Yogabyasa is called Pranayama prana means" +"gas, ayama means journey. In Pranayama practice air is allowed to enter" +"T" +"" +"" +"" +"three lobes of lungs inorder to increase the amount of oxygen to diffuse" +"into blood. Deep breaths in Pranayama helps us to reduce breathings per" +"ER" +"" +"" +"" +"" +"minute form 20-22 to 15. Because of these deep breaths more amount of" +"oxygen available to brain and tissues of the body will be more active. It is" +"very important to practice Pranayama regularly to make our life healthy" +"and active. All people irrespective of age and sex should practice Pranayama" +"under the guidance of well trained Yoga Teacher to improve the working" +"SC" +"" +"" +"" +"" +"capacity of lungs." +"" +"" +"" +"" +"Free distribution by T.S. Government 2019-20 47" +" A" +"Chapter" +"" +"" +"" +"" +"AN" +"3" +"" +"" +"NG" +"Transportation - The circulatory system" +"LA" +"All the living organisms need nutrients, gases, liquids etc., for growth" +"and maintenance of the body." +"All the organisms would need to send these materials to all parts of" +"their body whether they are unicellular organisms or multicellular." +"In unicellular organisms these may not have to be transported to longer" +"TE" +"" +"distances while in multicellular forms have to be sent substances to long" +"distances as far as say over 100 feet for the tallest plant on earth." +"In lower organisms like amoeba, hydra etc., all the materials are" +"transported through a simple processes like diffusion, osmosis etc.," +"In higher animals with trillions of cells in their body adopt the method" +"T" +"" +"" +"" +"of diffusion and osmosis only for the bulk movement of materials, would" +"takes years." +"ER" +"" +"" +"" +"" +"To avoid delay a separate system is needed to carry the materials much" +"faster and more efficiently." +"This specialized system that is developed by organisms is called ‘the" +"circulatory system’." +"We eat solids, we drink liquids, and we breathe gases. Do you think" +"SC" +"" +"" +"" +"" +"that it is possible to transport all the three types of materials, through a" +"single system?" +"Let us study how this circulation is carried out in our body." +"Have you ever observed a doctor holding the wrist of the patient and" +"looking at his watch for a minute? What is that he is trying to find out from" +"the watch and the wrist of the patient? You may wonder to know that he is" +"" +"48 X Class Transportation - The circulatory system" +" counting the heart beat of the patient. Don’t you think that is crazy, holding" +"the hand to count the heart beat?" +"" +"" +"" +"" +"A" +"Activity-1" +"You could try to find out for yourself, what the doctor was doing. Keep" +"" +"" +"" +"" +"AN" +"your index and middle fingers on your wrist below the thumb as shown in" +"the fig-1." +"What did you feel?" +"You feel something pushing your fingers rhythmically" +"up and down. Now let us count the rhythm which is called" +"" +"" +"" +"" +"NG" +"the pulse, for a minute. Now stand up and jog for one minute" +"at the same place. Note the pulse for a minute. Take" +"readings atleast two of your friends in the same manner" +"and record in the following table. fig-1: Pulse" +"" +"Table-1" +"LA" +"S.No Name of the person Pulse rate per minute" +"at rest after jogging" +"TE" +"" +"What did you observe? Is the pulse rate same in both conditions?" +"Activity-2" +"T" +"" +"" +"We see that pulse rate varies from person to" +"person and situation to situation. So it is not constant," +"ER" +"" +"" +"" +"" +"when you are afraid or excited the pulse rate goes up." +"Observe your pulse rhythm in other ways as well such" +"as climbing stairs, running, etc. There is a relationship" +"between the pulse rate and the beat of our heart. Now" +"let us try to find out more about this relationship." +"SC" +"" +"" +"" +"" +"fig-2: Matchstick stethoscope" +"For this you have to make your own stethoscope." +"Take a shirt button insert a matchstick as shown in" +"fig-2. Place it on your wrist. Observe movements in matchstick." +"What did you find?" +"When do you think that our pulse rate goes up?" +"What does the pulse rate show?" +"" +"Free distribution by T.S. Government 2019-20 49" +" Do you know?" +"Children over 10 Well-" +"" +"" +"" +"" +"A" +"Newborn Infants Infants Children years & adults," +"including trainedadults" +"(0–3 months) (3-6 months) (6–12 months) (1-10 years)" +"senior citizens athletes" +"" +"" +"" +"" +"AN" +"100-150 90-120 80-120 70-130 60-100 40-60" +"" +"In the year 1816, Rene Laennec discovered the Stethoscope. Before" +"the discovery of stethoscope doctors used to hear heart beat by keeping" +"ear on the chest of the patient. Laennec found that paper tube helps to hear" +"" +"" +"" +"" +"NG" +"the heart beat perfectly. Then he used a bamboo instead of paper tube to" +"hear heart beat. Laennec called it stethoscope." +"Activity-3" +"Let us repeat the work done by Laennec." +"LA" +"Make a paper tube 10 inch long and one inch in diameter. Keep one" +"end of it on the chest of your friend on a point one inch to the left side to" +"the centre around 6 inches below from his or her neck. Keep your ear at" +"the other end. Listen carefully and count the heart beats for a minute." +"Also count down your friend’s pulse rate. Note observations of at least" +"TE" +"" +"10 students of your class in the following tabular form." +"" +"Table-2" +"S.No Name of the student Heart beat at rest/min Pulse rate at rest/min" +"1 Eshwar 72 72" +"T" +"ER" +"" +"" +"" +"" +"Let us plot histogram on heart beat and pulse rate of" +"different persons as shown in the sample graph. Here" +"blue bar indicates heart beat, red bar indicates pulse rate." +"SC" +"" +"" +"" +"" +"What is the relationship between the heart beat" +"and the pulse?" +"Eshwar Can we say, the pulse rate is always equal to the" +"heart beat?" +"x-axis: Name of the student You might have studied there is a relation between" +"y-axis: Heart beat, pulse rate per minute" +"pulse rate and heart beat." +"" +"50 X Class Transportation - The circulatory system" +" Now try to understand the structure and method of working of this" +"vital organ, the heart. It is the beat of the heart which keeps us alive. Heart" +"is located in between the lungs and protected by rib cage. The size of your" +"" +"" +"" +"" +"A" +"heart is approximately the size of your fist." +"" +"" +"" +"" +"AN" +"NG" +"fig-3: Location of Heart fig-4: Heart" +"External features" +"Lab Activity" +"LA" +"Aim: Observation of the internal structure of the mammalian heart." +"Material required: Freshly collected specimen of heart of sheep or" +"TE" +"" +"goat from the butcher. Soda straws, used pen refils, sharp and long blade" +"or scalpel, tray, a jug of water, Dissection scissors, forceps." +"Since the structure of all the mammalian hearts are similar, we take" +"the sheep’s or goat’s heart for our observation. For this, we need following" +"materials." +"Procedure for observation:" +"T" +"" +"" +"" +"Before coming to the class wash the heart thoroughly so that, blood is" +"completely drained from the chambers of heart." +"ER" +"" +"" +"" +"" +"Take soda straws and insert them into the stumps of the blood vessels." +"Note your observations as you proceed." +"How many layers are covering the heart?" +"(Now remove the layers covering the heart, and observe)" +"SC" +"" +"" +"" +"" +"What is the shape of the heart?" +"How many large blood vessel stumps are attached to the heart?" +"Which end of the heart is broader and which end is narrow?" +"Observe the arrangement of blood vessels (coronary vessels) on the" +"wall of the heart." +"(In case you don’t have a model or a goat’s heart, look at the figures" +"given carefully for observation)" +"Free distribution by T.S. Government 2019-20 51" +" Internal structure of the heart" +"Keep the heart in the tray in such a way that a large arch like tube faces" +"upwards. This is the ventral side." +"" +"" +"" +"" +"A" +"Now take a sharp blade or scalpel and open the heart in such a way that" +"the chambers are exposed. Take the help of the fig-5." +"" +"" +"" +"" +"AN" +"arteries to head" +"artery to left arm" +"" +"superior vena cava" +"aorta" +"pulmonary artery (left branch)" +"" +"" +"" +"" +"NG" +"pulmonary artery (right branch)" +"left pulmonary veins" +"right pulmonary veins" +"left atrium" +"right atrium semi - lunar valve in the" +"pulmonary artery" +"" +"right atrio ventricular valve" +"LA left atrio ventricular value" +"(Tricuspid Valve) (Bicuspid Valve)" +"left ventricle" +"inferior vena cava" +"right ventricle" +"TE" +"" +"fig-5: Internal structure of heart" +"Now observe the internal structure. Observe the wall of the heart." +"Is the thickness of the wall of the heart uniform throughout?" +"How many chambers are there in the heart?" +"Are all the chambers of the same size?" +"T" +"" +"" +"What other differences could you observe between the chambers?" +"Do you find any specific observation in between two chambers?" +"ER" +"" +"" +"" +"" +"Are all the chambers connected to each other?" +"How are they connected to each other? How are they separated?" +"You can observe white coloured structures in the lower part of the" +"heart. Note down the size, shape and to which parts they are attached. Can" +"you guess the function of these structures?" +"SC" +"" +"" +"" +"" +"Write a note on your observations of the heart. Compare your notes" +"with the description given below." +"The heart is a pear shaped structure, triangle in outline, wider at the" +"anterior end and narrower at the posterior end." +"The heart is covered by two layered membrane. This is called" +"Pericardium (pericardial membrane). The space between these two layers" +"is filled with pericardial fluid, which protects the heart from shocks." +"52 X Class Transportation - The circulatory system" +" The heart is divided into four parts externally by grooves." +"Two upper parts are called atria (auricles), and the lower ones are called" +"ventricles." +"" +"" +"" +"" +"A" +"The blood vessels found in the walls of the heart are coronary vessels" +"which supply blood to the muscles of the heart." +"" +"" +"" +"" +"AN" +"The walls of the ventricles are relatively thicker than atrial walls." +"In our observation we found that the heart has four chambers in it. On" +"the left side two chambers are present, one is anterior and the other is the" +"posterior. On the right side also two chambers present, one upper (anterior)," +"and one lower (posterior)." +"" +"" +"" +"" +"NG" +"The left atrium and ventricle are smaller when compared to that of" +"right atrium and ventricle." +"Observe the presence of blood vessels attached to the heart." +"How many blood vessels are attached to the heart?" +"Are all the blood vessels are rigid? How many of them are rigid?" +"LA" +"Do you think that the stiffness/rigidity of blood vessel is something" +"to do with circulation?" +"Arteries are the blood vessels which originate from the heart and supply" +"blood to various organs in the body. They have thick walls. The largest" +"TE" +"" +"artery is aorta. The relatively smaller one is pulmonary artery which carries" +"blood from the heart to the lungs." +"The veins are the blood vessels which bring blood from all body parts" +"to the heart. Veins have relatively thinner walls. The vein which is at the" +"anterior end of the right side of the heart is superior venacava (precaval" +"vein), which collects blood from anterior parts (head and neck) of the" +"T" +"" +"" +"body." +"The vein which brings blood from posterior parts of the the body (hands," +"ER" +"" +"" +"" +"" +"legs etc.) is inferior venacava (postcaval vein)." +"The two atria and the two ventricles are separated from each other by" +"muscular partitions called septa. The openings between atria and ventricles" +"are guarded by valves." +"The valve present on the Right Auriculo-ventricular septum between" +"SC" +"" +"" +"" +"" +"Right atrium and Right Ventricle is referred to as “Tricuspid Valve”. The valve present on" +"the left Auriculo-ventricular septum between left atrium and left ventricle is referred as" +"Bicuscid valve or Mitral valve. A major blood vessel that originate from right ventricle is" +"Pulmonary aorta. The valves present at the region of Pulmonary aorta are called" +"“Pulmonary valves”. A major blood vessel originates from left ventrical is systemic aorta." +"The valves present at the region of systemic aorta are called Systemic valves." +"" +"Free distribution by T.S. Government 2019-20 53" +" In the right atrium we can observe the openings of superior and inferior" +"venacava. In the left atrium, we can observe the openings of pulmonary" +"veins, that bring blood from lungs." +"" +"" +"" +"" +"A" +"From the upper part of the left ventricle, a thick blood vessel called" +"aorta arises. It supplies oxygenated blood to the body parts. From the upper" +"" +"" +"" +"" +"AN" +"part of the right ventricle pulmonary artery arises that supplies de-" +"oxygenated blood to the lungs. After careful examination we can observe" +"valves in the pulmonary artery and aorta as well." +"The blood vessels and circulation" +"Let us study how we came to know about the structure and functions" +"" +"" +"" +"" +"NG" +"of the blood vessels." +"It was not until 16th century that we really came to know how our blood" +"vessels functioned. In 1574, an Italian doctor, Girolamo Fabrici, was" +"studying the veins in the leg. He noticed that they had small valves in them." +"If the blood moved in one direction, the valves folded towards the walls of" +"LA" +"the vessel, so that the blood could pass without trouble. If the blood moved" +"in the opposite direction, the valves closed." +"This meant they are one-way valves. The valves permitted the blood to" +"move even when a person is standing upright. But not move downward." +"When a person moves his legs, or just tightens his leg muscles, those" +"TE" +"" +"muscles squeeze the veins and force the blood in those veins to move" +"upward against the pull of gravity (because that’s the only way to go). If a" +"person keeps his leg muscles relaxed, the blood isn’t moving much, but at" +"least it isn’t being pulled down by gravity. The valves won’t allow that." +"Everyone thought that the blood leaving the left ventricle always moved" +"T" +"" +"" +"away from the heart for which Fabrici paid no attention. He missed the" +"importance of his own discovery. But then, William Harvey (1578-1657)," +"an Englishman who, after he became a doctor, went to Italy for further" +"ER" +"" +"" +"" +"" +"education and studied under Fabrici." +"Harvey dissected the hearts of dead people and studied the valves" +"between each atrium and its ventricle. He noticed that they were one-" +"way valves. They allowed the blood to flow from the atrium to the" +"SC" +"" +"" +"" +"" +"ventricle without any hinderance." +"When the heart contracted, however, no blood in the ventricle" +"could flow back into the atrium. Instead, all the blood was pushed out" +"into the arteries." +"fig-6: William Harvey began thinking about the valves his teacher, Fabrici, had" +"Harvey discovered in the leg veins. They were one-way, and they forced the" +"blood to move toward the heart." +"" +"54 X Class Transportation - The circulatory system" +" He checked that by tying off and blocking different veins in animals he" +"experimented on the veins always bulged on the side of the block away from" +"the heart. As though the blood as trying to flow toward the heart and to" +"" +"" +"" +"" +"A" +"accumulate just below the block because it simply couldn’t flow away from" +"the heart. This was true of all veins." +"" +"" +"" +"" +"AN" +"In the arteries, the blood bulged on the heart side of any block he put in," +"as though it were trying to flow away from the heart and couldn’t move in the" +"other direction." +"Harvey now saw what was happening. The heart pushed blood into the" +"arteries, and the blood returned by way of the veins. It did this for both" +"ventricles. The blood had a double circulation. If one started from the right" +"" +"" +"" +"" +"NG" +"ventricle, it left by way of the arteries to the lungs, and returned by way of the" +"veins to the left atrium is known as pulmonary circulation and from there" +"into the left Ventricle.From the left ventricle, it left by way of the arteries to" +"the rest of the body and returned (in a “greater circulation”) by way of the" +"veins to the right atrium and from there into the right ventricle. It is known as" +"systemic circulation. As the blood reaches the heart two times, once through" +"LA" +"pulmonary cycle and again through systemic cycle, it is called double" +"circulation." +"Harvey also showed that it was impossible, suppose that the blood was" +"used up in the body and that new blood was formed. He measured how" +"TE" +"" +"much blood the heart pumped in one contraction and also counted the" +"number of contractions." +"He found that in one hour, the heart pumped out a quantity of blood" +"that was three times the weight of a man. The body couldn’t use up" +"blood and form new blood at such a rate. The same blood had to circulate" +"and be used over and over again." +"T" +"" +"" +"Harvey still had some problem. The smallest arteries and veins that" +"could be seen had to be connected by vessels too small to see. Were fig-7: Marcello" +"they really there?" +"ER" +"" +"" +"" +"" +"Malpighi" +"In the 1650s, scientists had learned to put lenses together in such a" +"way that objects too small to see with the naked eye could be magnified and" +"made visible. Marcello Malpighi (1628-1694), with the microscope, he could" +"see tiny blood vessels that were invisible with naked eye." +"In 1661, four years after Harvey’s death, Malpighi studied the wings of" +"SC" +"" +"" +"" +"" +"bats. He could see blood vessels in their thin membranes and, under the" +"microscope; he could see that the smallest arteries and veins were connected" +"by very fine blood vessels." +"He called these blood vessels “capillaries” from the Latin word for “hair”," +"because they were as thin as the finest of hairs." +"With the discovery of capillaries, the idea of the circulation of the blood" +"was complete, and it has been accepted ever since." +"Free distribution by T.S. Government 2019-20 55" +" Now, we know that blood circulates in the blood vessels." +"But how did the scientists find out that blood moves in blood" +"vessels? Is it possible to demonstrate the movement of blood" +"" +"" +"" +"" +"A" +"in vessels without damaging the vessels?" +"Let us repeat the classical experiment to demonstrate" +"" +"" +"" +"" +"AN" +"the movement of blood in veins conducted by William Harvey" +"fig-8(a): Try like this in early 17 th century, when there was no compound" +"microscope or any other modern equipment." +"1. Tie a tornquit just above the elbow of a person as shown" +"in fig-8(b) whose blood vessels are prominent in the hand." +"" +"" +"" +"" +"NG" +"2. Ask him/her to hold the fist with a piece of cloth rolled" +"in the hand. Now the blood vessels can be seen more" +"prominently." +"3. Find undivided blood vessel, where we have to work for" +"the next few minutes." +"LA" +"4. At the end of the vessel farthest from the elbow apply" +"steady pressure, so as to close its cavity." +"5. Now apply pressure from elbow towards the palm slowly" +"and observe the changes in the blood vessels. (Take the" +"TE" +"" +"fig-8(b): Harvey’s help of the figures given here.) Observe changes and" +"demonstration discuss in your class." +"Answer the following:" +"In which blood vessels valves are found? What do you think is the" +"function of the valves in them?" +"T" +"" +"" +"Why do sub-cutaneous blood vessels bulge on the side away from" +"the heart when the hand is tied?" +"ER" +"" +"" +"" +"" +"The deep seated blood vessels (the arteries) bulge on the side" +"towards the heart when tied. What do you understand from it?" +"There are valves in the heart between atria and ventricles. Is the" +"purpose of valves in the veins and heart same?" +"Why the arteries are deeply seated in the body? Where as veins are" +"SC" +"" +"" +"" +"" +"seated on peripheral part of the body?" +"Arteries and veins" +"There are two types of blood vessels called arteries and veins. Arteries" +"carry blood from the heart to body parts. Whereas, veins carry blood from" +"body organs to heart. Let us observe the structural and functional" +"differences between arteries and veins." +"56 X Class Transportation - The circulatory system" +" tough fibrous coat" +"" +"" +"muscle layer lumen" +"" +"" +"" +"" +"A" +"elastic lumen" +"fibrous coat lining cells" +"lining cells" +"(endothelium)" +"(endothelium)" +"" +"" +"" +"" +"AN" +"fig-9(a): T.S. of Artery fig-9(b): T.S. of Vein fig-9(c): T.S.of Blood capillary" +"" +"Blood capillaries" +"Blood capillaries are the microscopic vessels made of single layer of" +"cells. They allow diffusion of various substances. The leucocytes (WBC)" +"can squeeze out of the capillary wall. They establish continuity between" +"" +"" +"" +"" +"NG" +"arteries and veins." +"After reading the experiments by Harvey fill in the following table." +"Use the clues/options given in the first column." +"Table-3" +"Structure / Function of blood vessel Artery Vein" +"LA" +"1. Thickness of walls(thick / thin)" +"2. Valves (present / absent)" +"3. Capacity to retain shape when blood is absent" +"TE" +"" +"(can retain/can’t retain)" +"4. Direction of blood flow (heart to organs / body" +"organs to heart)" +"5. Pressure in the vessel(low /high)" +"6. Type of blood transported" +"T" +"" +"" +"(oxygenated / de-oxygenated)" +"Discuss the differences between pulmonary artery and pulmonary" +"ER" +"" +"" +"" +"" +"vein." +"" +"Activity-4" +"Let us perform the following activities to observe arteries and veins." +"Sit on a table with one leg dangling and the other resting on it so that the" +"SC" +"" +"" +"" +"" +"back of one knee rests on the knee of the other. After a time you will see and" +"feel the leg which is on top give a series of small movements with each heart" +"beat. If you do it for long you will reduce the blood flow to the leg and so" +"develop ‘pins and needles’. Discuss with your teacher about reasons." +"Swing your arm round several times to fill the veins with blood, hold" +"the arm vertically downwards and gently press your finger along a prominent" +"vein-stroking it in the reverse direction to the blood flow, i.e., towards the" +"Free distribution by T.S. Government 2019-20 57" +" hand. Can you see the swellings where you have pushed blood against the" +"valves? Discuss with your teacher about reasons." +"" +"" +"" +"" +"A" +"Think and discuss" +"" +"" +"" +"" +"AN" +"Artery walls are very strong and elastic. why?" +"Why we compare arteries like tree which divides into smaller and smaller branches." +"The lumen size is bigger in vein when compared with artery. Why?" +"The cardiac cycle" +"" +"" +"" +"" +"NG" +"The human heart starts beating around 21st day during the" +"embryonic development (refer reproduction chapter). If it stops" +"beating, it results in the death of a person." +"One contraction and one relaxation of atria and ventricles" +"is called one cardiac cycle." +"LA" +"1. We start with the imagination that all the four chambers of" +"1. Imaginary relaxation the heart are in relaxed state (diastole)." +"of atria and ventricles." +"2. Blood from venacava and pulmonary veins enters the right" +"and left atria respectively." +"3. Now the atria contract, forcing the blood to enter into the" +"TE" +"" +"ventricles." +"4. When the ventricles are filled with blood they start" +"contracting and atria start relaxing. The aperture between" +"2. Blood flows into atria." +"the atria and ventricles is closed by valves. On ventricular" +"contraction due to pressure the blood moves into the aorta" +"T" +"" +"" +"and pulmonary artery. When the valves are closed forcibly," +"we can listen to the first sharp sound of the heart lub." +"ER" +"" +"" +"" +"" +"5. When the ventricles start relaxing the pressure in the" +"ventricles is reduced. The blood which has entered the" +"3. Contraction of atria and arteries tries to come back into the ventricles. The valves" +"flow of blood into ventricles. which are present in the blood vessels are closed to prevent" +"backward flow of blood into the ventricles. Now we can" +"SC" +"" +"" +"" +"" +"listen to a dull sound of the heart dub. The atria are filled up" +"with blood and are ready to pump the blood into the" +"ventricles." +"The sequential events in the heart which are cyclically" +"4. Contraction of ventricles. repeated are called cardiac cycle. The cardiac cycle includes an" +"A.V. Valves closed (Lub) active phase systole and a resting phase the diastole of atria and" +"blood flows into arteries. ventricles." +"58 X Class Transportation - The circulatory system" +" The time needed for atrial contraction (atrial systole) is 0.11-" +"0.14 seconds. The time needed for ventricular contraction" +"(ventricular systole) is 0.27-0.35 seconds. The time needed for" +"" +"" +"" +"" +"A" +"relaxation of both auricles and ventriculars i.e. joint diastole is about" +"0.4 seconds. The whole process is completed in approximately 0.8" +"" +"" +"" +"" +"AN" +"seconds." +"5. Relaxation of" +"Hence, naturally the blood is pumped into the blood vessels at ventricles. The" +"regular intervals. The tissues will not receive the blood continuously, closing of arterial" +"but in the form of spurts. When we keep our finger at the wrist, where valves (Dub)." +"the artery is passing into the hand we feel the pressure of blood moving" +"" +"" +"" +"" +"NG" +"fig-10(1-5):" +"in it. This is the pulse. The rate of the pulse will be equal to the Cardiac cycle" +"number of heart beats." +"" +"Do you know?" +"Name of the No. of" +"Weight of the body Weight of the heart" +"animal" +"LA beats/min" +"Blue whale 1,50,000 kg 750 kg 7" +"Elephant 3000 kg 12 - 21 kg 46" +"Man 60-70kg 300 gm 76" +"TE" +"" +"Coaltit (Bird) 8 gm 0.15 gm 1200" +"" +"Single /double circulation" +"We know that blood flows in" +"the blood vessels. To keep the" +"T" +"" +"" +"blood moving the heart pumps it" +"continuously. The blood that is" +"ER" +"" +"" +"" +"" +"pumped by the heart reaches the" +"body parts and comes back to the" +"heart. But course taken by the" +"blood is not the same in all the" +"animals. Let us observe the fig-" +"SC" +"" +"" +"" +"" +"11(a) and (b). Start from any point" +"in the fig-11(a) and (b). Move in" +"the direction of arrow. Note down" +"the parts which are in the way in" +"cyclical form." +"(Try to identify different parts fig-11(a): Single fig-11(b): Double" +"of the body in both figures.) circulation circulation" +"" +"Free distribution by T.S. Government 2019-20 59" +" Compare the two flow charts and answer the following." +"How many times did your pointer touch body parts in fig-11(a) and (b)?" +"How many times did your pointer touch the heart in fig-11(a) and (b)?" +"" +"" +"" +"" +"A" +"How many times did your pointer touch the respiratory organs in" +"fig-11(a) and (b)?" +"" +"" +"" +"" +"AN" +"From your observation it is clear that in fig -11(a) blood flows through" +"heart only once to complete one circulation." +"If blood flows through heart only once for completing one circulation" +"it is called single circulation." +"If the blood flows through the heart twice for completing one" +"" +"" +"" +"" +"NG" +"circulation it is called double circulation." +"Lymphatic system" +"Have you ever observed what happened to your feet after overnight" +"journey, in sitting position without moving? We feel that our foot wear is" +"little tight. In elders it will be clear that the lower part of the legs will be" +"LA" +"swollen. This stage is called edema." +"Why do our legs swell?" +"As blood flows through tissues and through blood capillaries" +"some amount of fluids and certain solid materials are constantly" +"TE" +"" +"flowing out of them at different junctions. Such materials are to" +"be collected and sent back into blood circulation." +"We know that blood circulates in the blood vessels, pushed by" +"the heart. From the heart it flows into the arteries and finally into" +"the capillaries. To supply nutrients to the cells (tissues), the liquid" +"T" +"" +"" +"portion of the blood with nutrients flows out of the capillaries." +"This" +"This is called tissue fluid." +"ER" +"" +"" +"" +"" +"The tissue fluid which is present in the tissues should be" +"transported into the blood vessels again. Some portion of the tissue" +"fluid enters into the venules, which in turn form the veins, which" +"carry blood to the heart. What about the remaining tissue fluid? To" +"transport the tissue fluid in to the main blood stream, a separate" +"SC" +"" +"" +"" +"" +"system is present. That is called lymphatic system. In latin lymph" +"means water." +"Lymph is the vital link between blood and tissues by which" +"essential substances pass from blood to cells and excretory" +"fig-12: Lymphatic products from cells to blood. The lymphatic system is a parallel" +"system system to venous system which collects tissue fluid from tissues" +"and transports it to the venous system." +"60 X Class Transportation - The circulatory system" +" Blood is a substance which contains solid and liquid particles. Lymph" +"is the substance that contains blood without solid particles. Tissue fluid is" +"lymph present in the tissues. The liquid portion after formation of blood" +"" +"" +"" +"" +"A" +"clot is serum." +"The muscles which are attached to the skeleton (skeletal muscles) act" +"" +"" +"" +"" +"AN" +"as pumps when they contract and help in pushing the lymph flowing in" +"lymphatic vessels and the blood flowing in veins towards the heart." +"The valves that are present in the lymphatic vessels and veins stop the" +"reverse flow of blood. We shall read about this as the system of lymph" +"circulation in detail in higher classes." +"" +"" +"" +"" +"NG" +"Evolution of the transport (circulatory) system" +"When the unicellular organisms separated themselves from the sea" +"with the formation of the limiting membrane, the problem of transportation" +"arose. The nature has found the solution, by creating a microscopic ocean" +"which has its own currents." +"LA" +"In unicellular organisms like Amoeba the protoplasm shows natural" +"movements. These movements are called Brownian movements, because" +"of which the nutrients and oxygen are distributed throughout the protoplasm" +"equally." +"TE" +"" +"This simplest intracellular transportation system, present in unicellular" +"animals has been retained in multicellular animals including humans. The" +"protoplasm of any cell in our body is mobile and protoplasmic currents" +"exist even in the nerve cells." +"The multicellular animals have to develop more complicated system" +"for transportation of materials." +"T" +"" +"" +"The parazoans like sponges, use sea water for transportation. Since" +"the natural water currents are not reliable, the sponges create their own" +"ER" +"" +"" +"" +"" +"currents by beating of flagella that are present in their body." +"The cnidarians which are better evolved than sponges (e.g. Hydra and" +"jelly fish) have developed blind sac like gastrovascular cavity, which has" +"taken up the function of digestion and transportation of nutrients to each" +"and every cell of the body." +"In platyhelmenthes (e.g. Fasciola hepatica), the digestive system is" +"SC" +"" +"" +"" +"" +"highly branched and supplies digested food to all the cells directly. In these" +"animals the excretory system collects wastes from each cell individually." +"In these organisms most of the body is occupied by digestive and excretory" +"systems." +"In animals belonging to Nemathelminthes (round worms), the" +"pseudocoelom has taken up the function of collection and distribution of" +"materials." +"Free distribution by T.S. Government 2019-20 61" +" The Annelids, the first Eucoelomate animals have developed a pulsatile" +"vessel, to move the fluid and the transporting medium is blood." +"The Arthropods have developed a pulsatile organ to pump the blood," +"" +"" +"" +"" +"A" +"the heart. The blood instead of flowing in blood vessels floods the tissues," +"directly supplying the nutrients to the tissues. Oxygen is directly supplied" +"" +"" +"" +"" +"AN" +"to the tissues directly by the respiratory system." +"Such type of transportation system which supplies nutrients to the" +"tissues directly is called open type of circulatory system.eg. Arthropods," +"many molluscs and lower chordates." +"The other type of transportation system where the blood takes the" +"" +"" +"" +"" +"NG" +"responsibility of delivering the materials, which flows in the blood vessels" +"is called closed type of circulatory system. Such type of closed circulatory" +"system is present in annelids echinoderms, cephalopod molluscs (e.g. (e.g" +"Octopus) and all the higher chordates." +"" +"Do you know?" +"LA" +"The human circulatory system can move one ml of blood from heart to a foot and" +"back which is approximately 2 meters, in about 60 seconds." +"It would take more than 60 years for the substance to move across this distance" +"TE" +"" +"by diffusion." +"Blood pressure (B.P.)" +"In class 9th we studied about blood and it’s components, blood grouping," +"etc., in the chapter animal tissues. Now we will discuss some other points" +"related to blood." +"T" +"" +"" +"Generally you have heard the word B.P. What is B.P.? To move the" +"blood through this network of vessels, a great deal of force is required." +"ER" +"" +"" +"" +"" +"The force is provided by the heart and is at its highest when the ventricles" +"contract, forcing the blood out of the heart and into the" +"arteries. Then there is a drop in the pressure as the ventricles" +"refill with blood for the next beat." +"B.P. is always measured in the upper arm artery. B.P." +"SC" +"" +"" +"" +"" +"varies throughout the body, so a standard place must be" +"used so that a person’s blood pressure can be compared" +"over a period of time. Doctors measure the blood pressure" +"(B.P.) with a device called sphygmomanometer." +"There are two pressure readings. One measures the" +"strongest pressure during the time blood is forced out of" +"fig-13: Sphygmomanometer the ventricles. This is called systolic pressure. For a healthy" +"62 X Class Transportation - The circulatory system" +" young adult it will be 120 mm of Hg. The second reading is taken during" +"the resting period, as the ventricles refill with blood. This is called diastolic" +"pressure. It will be 80 mm of Hg." +"" +"" +"" +"" +"A" +"B.P. will change according to the activity in which the person is" +"engaged, such as resting, walking and running. People who have high B.P." +"" +"" +"" +"" +"AN" +"during resting period are said to have hypertension. Discuss with your" +"teacher about low blood pressure." +"Coagulation of blood" +"Another important part in the story of blood is coagulation. Only" +"because of this character animals survive when they meet severe injuries." +"" +"" +"" +"" +"NG" +"When there is an injury blood clots in 3-6 minutes. How does the" +"blood clot? What chemistry involved in blood coagulation. You know that" +"when you cut yourself, the blood flows out of the wound for only a short" +"time. Then the cut is filled with a reddish solid material. This solid is" +"called a blood clot. If blood did not clot, anyone with even a slight wound" +"bleeds profusely." +"LA" +"When the blood flows out, the platelets release an enzyme called" +"thrombokinase." +"Thrombokinase acts on another substance present in the blood called" +"pro-thrombin converting it into thrombin." +"TE" +"" +"Thrombin acts on another substance called fibrinogen, that is present" +"in dissolved state converting it into insoluble fibrin." +"The blood cells entangle in the fibrin fibres forming the clot." +"The fibrin fibres are attached to the edges of the wound and pull them" +"together." +"T" +"" +"" +"The yellowish straw coloured fluid portion after formation of the clot" +"is serum." +"Prothrombrin Thrombrokinase" +"ER" +"" +"" +"" +"" +"Thrombin" +"Fibrinogen Thrombin Fibrin" +"Discuss with your teacher about vitamin K in relation to coagulation" +"of blood." +"SC" +"" +"" +"" +"" +"fig-14(a): Blood in the blood vessel fig-14(b): Clot formation" +"" +"Free distribution by T.S. Government 2019-20 63" +" Normally the blood that oozes from a wound clots in 3-6 minutes. But" +"in some people due to vitamin K deficiency it takes more time. Because" +"of genetic disorder the blood may not coagulate. This type of disorder is" +"" +"" +"" +"" +"A" +"called haemophilia. Haemophilia is common disorder in the children who" +"have born from marriages between very close relatives. Thalassemia an" +"" +"" +"" +"" +"AN" +"inherited disorder is also related to blood. For more details see annexure." +"" +"HOW MATERIALS TRANSPORT WITH IN THE PLANT" +"" +"There is a vast transport system in continual supply of essential" +"" +"" +"" +"" +"NG" +"nutrients and oxygen to perform metabolic activities, and to remove" +"excretory substances which are found in each cell of animal body." +"Is there anything like that in plants which corresponds to circulatory" +"system?" +"In previous classes we studied about Van Helmont’s" +"LA" +"experiments on plants, which get water that contain minerals" +"from soil through their roots. The water absorbed by roots" +"and food prepared by leaves are supplied to the remaining" +"parts of the plant by vascular bundles having xylem and phloem." +"In the root, the xylem tissue develops from periphery to" +"TE" +"" +"center, whereas in the stem it develops from center to" +"fig-15: Transportation periphery in each vascular bundle." +"How is water absorbed?" +"We know that roots absorb water with minerals from soil." +"What is the mechanism behind this?" +"T" +"" +"" +"" +"Are roots directly in contact with water?" +"How is water absorbed?" +"ER" +"" +"" +"" +"" +"Activity-5" +"Absorbing root hairs" +"To perform this activity, you need to germinate bajra or mustard seeds." +"SC" +"" +"" +"" +"" +"Examine some mustard seedlings which have been grown on wet filter" +"paper. Observe the mass of fine threads coming from the seed by hand" +"lens. These are roots. They have fine microscopic structures called root" +"hairs. These are root hairs through which water enters the plant. Gently" +"squash a portion of the root hair between slide and cover slip in a drop of" +"water and examine under a microscope. Note the thinness of the walls of" +"root hairs. It is not completely understood how the water enters the root" +"hairs and passes inwards from cell to cell until it gets into the xylem vessels," +"" +"64 X Class Transportation - The circulatory system" +" but there is no doubt that osmosis plays an important role.(IX class" +"plasmamembrane)" +"Every living cell acts as an osmotic system, the cytoplasm lining of" +"" +"" +"" +"" +"A" +"the cell wall acts as the semipermeable membrane. Observe the following" +"figure, notice how do roots penetrate into soil? You will find that the root" +"" +"" +"" +"" +"AN" +"hairs grow out into the spaces between the soil particles and that the hairs" +"are surrounded by moisture." +"" +"" +"epidermal cell" +"" +"" +"" +"" +"NG" +"soil particles" +"soil water" +"xylem vessel" +"nucleus" +"air spaces" +"" +"" +"cells of cortex cell wall of root hair" +"LA vacuole" +"cellsap" +"" +"fig-16: L.S of root showing relationship of root hair and soil water" +"" +"Note: In fig-16 Arrow marks shows the direction of flow of water." +"TE" +"" +"The soil water is an extremely dilute solution of salts. Soil water" +"concentration is more dilute than that of the cell sap in the root hair;" +"therefore water will pass into the vacuole of the root hair by osmosis." +"Recall the process of osmosis that you have learnt in the chapter “moving" +"of substances through plasma membrane” in class IX. The entry of water" +"T" +"" +"" +"dilutes the contents of the root hair vacuole so that it becomes more dilute" +"than it’s neighbouring cell." +"So, water passes into the neighbouring cell which in turn becomes" +"ER" +"" +"" +"" +"" +"diluted, finally water enters the xylem vessels. As there are vast number of" +"root hairs and root cells involved, a pressure in the xylem vessels develops" +"which forces the water upwards. This total pressure is known as root" +"pressure. Root pressure is not the main cause of movement of water in" +"xylem but it is certainly one of the factor. The other factors are also there." +"SC" +"" +"" +"" +"" +"You will learn about those reasons in higher classes in detail." +"Activity-6" +"What is root pressure" +"Take a regularly watered potted plant and cut the stem portion 1 cm" +"above the ground level. Then connect a glass tube by means of strong rubber" +"Free distribution by T.S. Government 2019-20 65" +" tubing as shown in the figure. The size of" +"clamp" +"glass tube should be equal to the size of the" +"glass tube stem. Take care while joining tube and stem" +"" +"" +"" +"" +"A" +"water level being bound tightly, so that water cannot" +"strong rubber tubing escape from the tube. Now, pour some water" +"" +"" +"" +"" +"AN" +"cut stem portion in the glass tube until water level can be seen" +"soil above the rubber tube. Mark the level of" +"water (M 1 ) in the tube. Keep your" +"arrangement aside for 2 to 3 hours. Then" +"water observe and mark the water level (M2) in the" +"" +"" +"" +"" +"NG" +"tube." +"Is there any increase in the water level?" +"fig-17: Root pressure What is the role of xylem in this action?" +"The difference between M2 and M-1 indicates the level of water raised" +"in the stem. Because of the root pressure, the water level increases in the" +"tube." +"LA" +"The mechanism of water movement in plants" +"We have seen that there is a push from below due to root pressure on" +"the columns of water in the xylem vessels, but this is seldom high and in" +"TE" +"" +"some seasons it is nil. How does the water reach 180 metres high to the" +"top of a tree like a eucalyptus?" +"Let us recall the activity that you performed in lower classes. Why" +"inner sides of cover become moist? Where do these water droplets or" +"water vapour come from?" +"T" +"" +"" +"We know that this type of evaporation of water through" +"leaves is called transpiration. Water evaporates through" +"ER" +"" +"" +"" +"" +"stomata of leaves and lenticels of stem." +"When the leaves transpire, there is a pulling effect on" +"the continuous columns of water in the xylem vessels. The" +"top ends of these vessels are surrounded by the leaf’s" +"mesophyll cells which contain cell sap, so the water is" +"SC" +"" +"" +"" +"" +"continuous from the xylem vessels to the walls of the" +"mesophyll cells from which it evaporates into the air spaces" +"causing the pull. The water column does not break because" +"of its continuous molecular attraction. This is a property of" +"water you demonstrate every time you drink through a straw." +"Now we have a picture of the water-conducting system" +"fig-18: Transpiration of a tree. Water is absorbed by osmosis from the soil by" +"66 X Class Transportation - The circulatory system" +" the root hairs. This is passed into the xylem vessels which form a continuous" +"system of tubes through root and stem into the leaves. Here the water" +"evaporates and releases into the atmosphere. The evaporation creates the" +"" +"" +"" +"" +"A" +"main pull of water above root pressure which gives a variable and minor" +"push from below. This results in a continuous column of moving water," +"" +"" +"" +"" +"AN" +"the ‘transpiration stream’." +"Is there any relation between transpiration and rain fall?" +"The amount of water passing through a plant is often considerable." +"For example, an oak tree can transpire as much as 900 liters of water per" +"day. It follows therefore that areas of forest significantly affect the degree" +"" +"" +"" +"" +"NG" +"of saturation of the air above them, so that when air currents bring air" +"which is already nearly saturated to a forest area, it becomes fully saturated" +"and comes down as rain; this is why forest areas often have a higher rainfall" +"than areas nearby. LA" +"Do you know?" +"How much water is transpired by plants? Each fully grown maize plant transpires 15" +"liters per week. One acre of maize may transpires more than 13,25,000 liters of" +"water in a hundred day growing season. A big mango tree will transpire from 750 to" +"TE" +"" +"more than 3500 liters of water per day during growing season." +"" +"Transport of mineral salts" +"You know that mineral salts are necessary for plant nutrition (micro" +"and macro nutrients) and that they are obtained from the soil solution" +"T" +"" +"" +"" +"through the root hairs. The salts are in the form of electrically charged" +"ions. Sodium chloride (NaCl) is in the form of Na+ and Cl-, and Magnesium" +"ER" +"" +"" +"" +"" +"Sulphate (MgSO4) occurs as Mg2+ and SO42-. But, they are not absorbed" +"into the root hairs by the simple process of diffusion, but it involves the" +"use of energy by the cytoplasm which will be discussed in later classes." +"Once ions are absorbed, the ions travel along with water in the xylem vessels" +"and pass to the growing points of the plants where they are used for growth" +"SC" +"" +"" +"" +"" +"purpose. They may also pass laterally from xylem to phloem. Thus, mineral" +"salts are one of the natural factors in plant growth phenomena." +"Transport of materials in plants" +"Food such as sugar is synthesised in the green parts of plants, mainly" +"the leaves, but this food has to be transported to all the living cells," +"especially to actively growing cells and the cells which stores food." +"Free distribution by T.S. Government 2019-20 67" +" The veins of a leaf consist of xylem and phloem," +"proboscis" +"and these tissues are continuous with the stem. The" +"following experiments provide evidence that food is" +"" +"" +"" +"" +"A" +"transported in the phloem cells." +"aphid" +"Phloem sieve tubes are extremely small and the" +"" +"" +"" +"" +"AN" +"analysis of their contents is not easy. Biologists" +"studied about food transportation in plants with the" +"help of aphids (greenfly). When you see aphids" +"phloem clustering round the young stems of plants as they" +"xylem" +"feed on the plant juices. To obtain this juice an aphid" +"" +"" +"" +"" +"NG" +"bark" +"pith pierces the plant tissues with its long needle like organ" +"“proboscis”. It can be shown when a feeding aphid is" +"fig-19: Aphid extracting food" +"material from plant killed and the stem carefully sectioned, the proboscis" +"only penetrates upto a phloem sieve tube. This" +"proboscis also provides a ready-made means of obtaining the juice for" +"LA" +"analysis! The experiment can be done in this way. An aphid is killed while" +"in the act of feeding and the body is then carefully cut away, leaving the" +"hollow proboscis still inserted into the phloem. It is found that because" +"the contents of the phloem sieve tubes are under slight pressure the fluid" +"slowly exudes from the cut end of the proboscis in the form of drops;" +"TE" +"" +"these drops are then collected and analysed. The fluid is found to contain" +"sugars and amino acids." +"Not surprisingly, aphids absorb so much sugar from the phloem that" +"they cannot assimilate all of it and it excretes out of the body as a sticky" +"syrup called honey dew. Leaves which have been attacked by aphids often" +"T" +"" +"" +"feel sticky as a result of honey dew." +"You may notice that sometimes barks of the" +"ER" +"" +"" +"" +"" +"tree damaged more than a half, even then the tree" +"some growth is alive. How is this possible?" +"roots Further experiments to illustrate the" +"conduction of sugars by the phloem have been" +"no growth" +"done by removing a ring of bark from a shoot to" +"SC" +"" +"" +"" +"" +"expose the wood. Remove all tissues from the" +"fig-20: Removing ring of bark center outwards, including the phloem. After a" +"(Ringing experiment) few days, when the tissues above and below the" +"ring were analyzed it was shown that food had accumulated above the ring," +"but was not present below it. If it is left for some more time, the stem" +"increases in thickness immediately above the ring, but no growth occurred" +"68 X Class Transportation - The circulatory system" +" below it. So, any damage to the phloem all around the stem will prevent the food from" +"passing down to the roots and the tree will eventually die. This is a fact of great economic" +"importance because certain mammals scratching the bark of trees to get the food stored in" +"" +"" +"" +"" +"A" +"the phloem, especially during hard winters when food is scarce. Voles (rat like rodents) do" +"this to young saplings at ground level and rabbits can do much damage to older ones." +"" +"" +"" +"" +"AN" +"Foresters find it economically worthwhile to enclose new plantations with wire netting to" +"prevent rabbits from entering." +"Foresters also encourage predators such as foxes, badgers, hawks and owls as they help" +"to keep down the population of voles and rabbits. Grey squirrels too do great damage," +"particularly Casurina crop grown at beech and seashore, and for this reason, in some parts" +"" +"" +"" +"" +"NG" +"it is impossible to grow these trees as a crop. Observe barks of trees in your surroundings" +"for evidence of bark having been gnawed off saplings and trees. Note the species of tree," +"the position of the damage, whether the damage is recent or old, and the size of tooth marks" +"if these are visible. From these observations you could find out which species had caused" +"the damage. Also look out for the effect of such damage on the tree as a whole." +"LA" +"Key words" +"Circulation, Auricles, Ventricles, Pulse, Artery, Vein, Stethoscope, Aorta, Capillary," +"Systole, Diastole, Cardiac cycle, Blood pressure, Lymph, Single circulation, Double" +"TE" +"" +"circulation, Coagulation of blood, Sphygmomanometer, Prothrombin, Thrombin," +"Fibrinogen, Fibrin, Root hair, Radical, Root pressure, Plant nutrients, Xylem, Phloem," +"Vascular bundles." +"T" +"" +"" +"" +"What we have learnt" +"ER" +"" +"" +"" +"" +"The pulse rate is equal to heart beat. We can count the heart beat without the aid of any instrument." +"Rene Laennec discovered the first stethoscope." +"The heart is covered with two pericardial membranes filled with pericardial fluid which protects it" +"from shocks." +"SC" +"" +"" +"" +"" +"Rigid blood vessels attached to the heart are called arteries. The two rigid blood vessels are" +"arteries which supplies blood to body parts and lungs." +"The less rigid vessels are veins, which brings blood from body parts." +"Heart has four chambers, two upper atria and two lower ventricles." +"Atrium and ventricle of the same side are connected by atrio ventricular aperture." +"Atria are separated from each other by interatrial septum, ventricles by interventricular septum." +"" +"Free distribution by T.S. Government 2019-20 69" +" The atrioventricular apertures are guarded by valves. There are valves in the aorta and pulmonary" +"artery also." +"" +"" +"" +"" +"A" +"The right side of heart receives blood from body and sends to lungs." +"The left side of the body receives blood from lungs and send it to body parts." +"" +"" +"" +"" +"AN" +"The arteries carry oxygenated blood except pulmonary artery. The veins carry deoxygenated blood" +"except pulmonary veins." +"One contraction and relaxation of heart is called cardiac cycle." +"If the blood goes to heart only once before it reaches all the body parts. It is called single circulation." +"If it goes twice it is called double circulation." +"" +"" +"" +"" +"NG" +"Vitamin K deficiency leads to delayed coagulation of blood." +"Plants absorb soil water through roots by the process of osmosis." +"Water travels through xylem vessels and food material travels through phloem tissues." +"There is a relation between tranportation and transpiration in plants." +"Biologists studied about phloem tubes with the help of aphids." +"LA" +"Improve your learning" +"" +"1. What is transport system? How does this help the organism?(AS1)" +"TE" +"" +"2. What is the relationship between blood and plasma?(AS1)" +"3. Which type of blood vessels carry blood away from the heart?(AS1)" +"4. What are the three main types of blood vessels in the body?(AS1)" +"5. Which is the largest artery in the body? Why is it the largest ?(AS1)" +"6. Which blood vessel carries blood for oxidation?(AS1)" +"T" +"" +"" +"" +"7. Name the structures which are present in veins and lymph ducts and absent in arteries.(AS1)" +"8. What is the use of platelets?(AS1)" +"ER" +"" +"" +"" +"" +"9. Write differences between (AS1)" +"a) systole - diastole b) veins - arteries c) xylem - phloem" +"10. Explain the way how the plants absorb water from soil ?(AS1)" +"11. What is root pressure? How it is useful to the plant?(AS1)" +"SC" +"" +"" +"" +"" +"12. Phloem is a food source for some animals. How can you justify this statement?(AS1)" +"13. Read the given para and name the parts of the heart.(AS1)" +"We have observed that the heart is divided into four chambers by muscular structure. Any" +"structure that divides two chambers is known as septum. Now let us try to name the septa present" +"in the heart." +"a) The septum that divides the two atria can be named as _____________" +"" +"70 X Class Transportation - The circulatory system" +" b) The septum that divides the two ventricles can be named as___________." +"c) The septum that divides the atrium and ventricle can be named as________." +"" +"" +"" +"" +"A" +"The holes that connect two chambers are called apertures.. Let us try to name the apertures" +"which connect the atria and ventricles." +"" +"" +"" +"" +"AN" +"d) The aperture that connects the right atrium and right ventricle can be named as_______." +"e) The aperture that connects the left atrium and left ventricle can be named ___________." +"Any structure that closes an aperture, and allows one way movement of materials is called as" +"valve.. Now let us name the valves that are present in the chambers of the heart." +"f) The valve that is present between left atrium and left ventricle can be named as____________." +"" +"" +"" +"" +"NG" +"g) The valve that is present between right atrium and right ventricle can be named as ___________." +"14. If the valves in veins of the legs fail to stop the flow of blood what could be the consequences of this" +"failure?(AS2)" +"15. What would happen if cell sap in the cells of root hair contain a high concentration of ions?(AS2)" +"16. John made a stethoscope using a paper cup and plastic tube. Write down the procedure he" +"LA" +"followed. (AS3)" +"17. How did scientists prove that the food is transported through the phloem?(AS3)" +"18. What is your inference about experiments with aphids?(AS3)" +"19. Collect information about blood pressure of your school teachers or nighbours. Prepare a report" +"TE" +"" +"on their health problems due to changes in blood pressure. (AS4)" +"20. Draw a block diagram to explain single and double circulation. Write differences between them.(AS5)" +"21. Prepare a block diagram showing water absorption by roots to transpiration by leaves . (AS5)" +"22. What can circulatory system in man be compared with? (AS6)" +"T" +"" +"" +"23. What is Haemphilia? (AS1)" +"24. Prepare a cartoon on heart beating? (AS7)" +"ER" +"" +"" +"" +"" +"25. After reading this lesson what precautions would you suggest to your elders about edima.(AS7)" +"" +"" +"Choose the correct answer" +"" +"1. The term cardiac refers to which organ in the body? ( )" +"SC" +"" +"" +"" +"" +"A) heart B) vein C) lymph D) capillary" +"2. In which chamber of the human heart the blood is low in oxygen? ( )" +"A) right atrium B) right ventricle C) left atrium D) A and B" +"3. Which structures of the heart control the flow of the blood? ( )" +"A) arteries B) veins C) valves D) capillaries" +"" +"" +"Free distribution by T.S. Government 2019-20 71" +" 4. Which of the following statement is wrong? ( )" +"A) Serum is the liquid portion formed after blood clotting." +"" +"" +"" +"" +"A" +"B) Lymph is the link between blood and tissues." +"C) The xylem and phloem transport water and food in plants." +"" +"" +"" +"" +"AN" +"D) In insects closed type of circulatory system is seen." +"5. An aphid pierces its proboscis into the ……… to get plant juices ( )" +"A) Xylem B) phloem C) cambium D) vascular bundle" +"" +"" +"Annexure-I" +"" +"" +"" +"" +"NG" +"The rhesus factor" +"There is another antigen of red blood cells which is present in 85% of the people of" +"Britain, this is known as the Rhesus factor, as it was first discovered in Rhesus monkeys." +"LA" +"People who have this are said to be Rhesus positive (Rh+). Those who do not have this" +"factor are termed Rhesus negative (Rh-). Normally they do not carry an antibody to this" +"factor in their plasma. However, if Rh+ blood is transfused into the blood of a Rh- person," +"against Rh-factors will be formed and these are capable of destroying Rh+ red cells. Under" +"TE" +"" +"certain circumstances this is a potential hazard for babies." +"If a Rh+ man marries a Rh- woman, some of the children are likely to be Rh+. At birth" +"there is always some mixing of blood between the circulation of mother and baby and this" +"may occasionally happen during pregnancy. So, if a child is Rh+ some of its blood will leak" +"T" +"" +"" +"into its mother’s circulation and cause antibodies to form in her blood. If the mother has" +"more children, not all will necessarily be Rh+, but if they are, the amount of antibodies in" +"ER" +"" +"" +"" +"" +"her blood often increases with each pregnancy, and in some instances the antibodies in her" +"blood may pass into the baby’s blood in sufficient quantities to produce very serious anaemia" +"and even death. Fortunately these cases are not frequent, and when they do occur, the baby" +"is given a complete transfusion soon after birth so that the baby’s blood is replaced by" +"SC" +"" +"" +"" +"" +"blood containing no antibodies to the rhesus factor. It is now possible for this transfusion" +"to be carrried out before birth. Another recently developed technique is for the mother to" +"be given an injection shortly after the birth of her first child which prevents the Rh+ cells" +"from stimulating the production of the harmful antibody." +"" +"" +"" +"" +"72 X Class Transportation - The circulatory system" +" Annexure-II" +"" +"" +"" +"" +"A" +"Thalassemia" +"Thalassemia is a group of inherited blood disorders characterized by mild to severe" +"" +"" +"" +"" +"AN" +"anaemia caused by haemoglobin deficiency in the red blood cells. In individuals with" +"thalassemia, the production of the oxygen carrying blood pigment haemoglobin is" +"abnormally low. There are two main types of thalassemia: alpha thalassemia and beta" +"thalassemia. In each variant a different part of the haemoglobin protein is defective." +"Individuals with mild thalassemia may have symptoms, such as anaemia, enlarged liver and" +"" +"" +"" +"" +"NG" +"spleen, increased susceptibility to infections, slow growth, thin and brittle bones, and heart" +"failure." +"Facts about Thalassemia" +"Thalassemia is a serious Inherited Blood Disorder." +"4.5% of world population (250 million) suffering with thalassemia minor." +"LA" +"There are over 35 million Indians are carriers of the abnormal Gene for Thalassemia." +"It is estimated that about 1,00,000 infants are born with major Haemoglobinopathies" +"every year in the world." +"10,000 – 12,000 Thalassemic children are born every year in our country." +"TE" +"" +"Survival depends upon repeated blood transfusion and costly medicines." +"Thalassemia can be prevented by awareness, pre marital or pre conceptual screening" +"followed by antenatal diagnosis is required." +"Treatment" +"Thalassemia major should be diagnosed as early as possible in order to prevent growth" +"T" +"" +"" +"" +"restriction, fragile bones and infections in the first year of life. The infant’s haemoglobin" +"levels and development should therefore be monitored closely. If Hb is less than 70% or" +"ER" +"" +"" +"" +"" +"the child shows signs of poor growth and development. Regular transfusion is the treatment" +"of choice. According to the WHO, the aim of this treatment is to retain a median haemoglobin" +"value of 115–120 grams per liter" +"liter. This can usually be achieved by carrying out transfusions" +"of concentrated red blood cells at intervals of every three to four weeks." +"SC" +"" +"" +"" +"" +"Today thalassemia major can be cured by stem cell transplantation. A prerequisite is" +"usually that the affected individual who has siblings with identical tissue type (HLA type) a" +"transplantation of blood stem cells referred to as a “bone marrow transplant”, can be carried" +"out." +"" +"" +"" +"" +"Free distribution by T.S. Government 2019-20 73" +" A" +"Chapter" +"" +"" +"" +"" +"AN" +"4" +"" +"" +"NG" +"Excretion - The wastage disposing system" +"LA" +"There is no factory which can manufacture a product without generating" +"any waste. This is true of our body which is a cellular factory too. And for" +"other organisms as well. Wastes are generated at regular intervals from" +"the bodies of most organisms. This raise questions like." +"Where are the wastes produced?" +"TE" +"" +"How are they produced?" +"What are the substances present in them?" +"Does the composition vary in the same organism in different" +"situations?" +"Let us understand such kind of questions." +"T" +"" +"" +"" +"Living beings need energy for their survival and to perform activities" +"either building up of body material (anabolism) or its breakdown" +"ER" +"" +"" +"" +"" +"(catabolism), collectively called metabolic activities. Organisms use" +"different substances for metabolic activities. Different products are" +"generated as a result of these metabolic activities. Can you name different" +"products generated by the following life processes?" +"Table-1" +"SC" +"" +"" +"" +"" +"Life processes Products" +"Photosynthesis" +"Respiration" +"Digestion" +"" +"74 X Class Excretion The wastage disposing system" +" What products would the organism be able to take up for other ac-" +"tivities?" +"What are the products which would cause harm to the body, if they" +"" +"" +"" +"" +"A" +"are not removed?" +"What happens if harmful products are not removed from our body" +"" +"" +"" +"" +"AN" +"every day?" +"We have already learnt that different kinds of materials are produced" +"out of various metabolic activities. Some of these may be harmful for the" +"organism are removed from their body or packed and stored in some other" +"forms. These are all the wastes produced in the body of an organism. We" +"" +"" +"" +"" +"NG" +"have already discussed how organisms get rid of gaseous wastes generated" +"during photosynthesis or respiration. Other metabolic activities generate" +"nitrogenous wastes have to be removed along with salts, excess water and" +"several other materials. Excretion is the term coined for all the biological" +"process involved in separation and removal of wastes or non useful" +"LA" +"products from the body. (In latin ex means out, crenere means shift.) Now" +"let us study how excretion takes place in human being." +"Excretion in Human Beings" +"A number of reactions take place during various metabolic activities." +"TE" +"" +"Many useful substances and energy are produced. At the same time many" +"other things happen such as, toxic wastes may be produced, water content" +"may increase, ionic balance (homeostasis) in the body may be disturbed." +"The waste products include carbon dioxide, water, nitrogenous compounds" +"like ammonia, urea, uric acid, bile pigments, excess salts etc. The most" +"T" +"" +"" +"poisonous of all waste products of metabolism is Ammonia." +"Where are these waste materials produced? How does the body manage" +"ER" +"" +"" +"" +"" +"them. Is there a way to detect their presence in our body?" +"Now let us observe the test reports of Blood and Urine of a person" +"given in table-2, 3 and find out the components present in both Blood and" +"Urine. (For 24 hours urine test urine is collected for 24 hours From that," +"100-150 ml sample will be tested.) observe the reports in the next page" +"SC" +"" +"" +"" +"" +"and answer the following questions." +"What are the substances present in blood?" +"What are the substances present in urine?" +"What are the substances present both in blood and urine?" +"Which substances are present above the normal limits both in the" +"blood and urine?" +"What do you think a reading above normal limits indicates?" +"Free distribution by T.S. Government 2019-20 75" +" Table-2: DEPARTMENT OF BIOCHEMISTRY" +"REPORT ON PLASMA/SERUM (BLOOD) ANALYSIS" +"" +"" +"" +"" +"A" +"TEST NAME RESULT UNITS RANGE" +"GLUCOSE FASTING 82 mg/dl 60-100" +"" +"" +"" +"" +"AN" +"SODIUM 137 mmoles/L 135-145" +"POTASSIUM 4.10 mmoles/L 3.5-5.0" +"CHLORIDES 101 mmoles/L 95-106" +"UREA 29 mg/dl 15-40" +"" +"" +"" +"" +"NG" +"CREATININE 2.8. mg/dl 0.6-1.5" +"URIC ACID 7.50 mg/dl 3.0-5.0" +"TOTAL CHOLESTEROL 221 mg/dl 150-200" +"TRIGLYCERIDES 167 mg/dl 60-200" +"CALCIUM 9.40 mg/dl 8.0-10.5" +"PHOSPHORUS" +"LA" +"4.50 mg/dl 3-4.5" +"BILIRUBIN (TOTAL) 0.70 mg/dl 0.1-0.8" +"TOTAL PROTEINS 7.20 g/dl 6.0-7.5" +"ALBUMIN 4.60 g/dl 3.0-5.0" +"TE" +"" +"Table-3: DEPARTMENT OF BIOCHEMISTRY" +"REPORT ON URINE ANALYSIS" +"TEST/METHOD RESULT" +"RESUL UNITS RANGE" +"24 hrs.Protein 90 mg/day <100 mg" +"T" +"" +"" +"24 hrs Creatinine 2.7 mg/day 1-2" +"24 hrs.Calcium 305 mg/day Up to 200" +"ER" +"" +"" +"" +"" +"24hrs.phosphorous 0.8 mg/day upto 1g" +"24hrs.uric Acid 800 mg/day upto 600" +"" +"ELECTROLYTES :" +"Sodium 140 mmoles/L 125-250" +"SC" +"" +"" +"" +"" +"potassium 50 mmoles/L 25-100" +"Osmolality (calculated) 180 mmoles/L 100-600" +"Glucose 65 mg/dl 50-80" +"Chlorides 128 mmoles/L 120-130" +"Urea 35 gm/day 20-30" +"m moles / L means millimoles per litre, mg/dl means milligram per deci litre." +"" +"76 X Class Excretion The wastage disposing system" +" What are the materials needed to be removed from our body?" +"From where do these materials removed?" +"What are the organs that seperate excretory materials?" +"" +"" +"" +"" +"A" +"Why do you think the body must remove waste substances?" +"Studying the structure and function of our excretory system will help" +"" +"" +"" +"" +"AN" +"us to understand this better." +"Excretory System in Human being" +"In human beings excretion mainly occurs through a urinary or" +"excretory system consisting of a pair of kidneys, a pair of ureters, urinary" +"" +"" +"" +"" +"NG" +"bladder and urethra, as shown in the fig-4. Now let us observe external and" +"internal features of a kidney in goat / sheep, which is similar to Human" +"kidney in function." +"" +"Lab Activity" +"LA" +"Aim: Studying the external and internal features of a kidney" +"Materials required: Freshly collected specimen of sheep/goat’s kidney" +"from the butcher or 3D Model of a kidney, sharp blade/scalpel, tray and a" +"jug of water." +"TE" +"" +"Procedure for observation: Before coming to the class wash the" +"kidney thoroughly so that, blood is completely drained from it. Put" +"the kidney in the tray and observe it carefully. Note your observations" +"in the observation book. With the help of sharp blade take a longitudinal" +"section here you are advised to do this activity under the guidance of" +"T" +"" +"" +"your teacher and observe the internal structure." +"Draw what you have observed and compare it with fig-1,2." +"ER" +"" +"" +"" +"" +"What is the shape of kidneys? fig-1: Kidney" +"of goat" +"What is the colour of kidney?" +"Do you find any attachments on upper portion of kidney?" +"Is the Internal structures similar to fig-2" +"What is the colour of the outer part in L.S of kidney?" +"SC" +"" +"" +"" +"" +"In L.S of kidney where do you find dark brown colour portion?" +"How many tubes are coming out from kidney fissure?" +"Don’t forget to wash your hands with antibacterial lotion after" +"completing dissection." +"Now let us know the structure of human excretory system and its fig-2: LS of" +"functions. Kidney of goat" +"" +"Free distribution by T.S. Government 2019-20 77" +" Kidneys" +"In Human beings there is a pair of bean shaped, reddish brown structures" +"" +"" +"" +"" +"A" +"in the abdominal cavity attached to dorsal body wall (fig-3) one on either" +"side of the back bone they are kidneys. The right kidney is placed slightly" +"lower than the left kidney. Think why it is so?" +"" +"" +"" +"" +"AN" +"The size of the kidney is 10 cm in length, 5-6 cm in breadth, and 4 cm" +"in thickness. Each kidney is convex on the outer side and concave on the" +"inner side. The position of the right kidney is lower than the left kidney" +"due to the presence of liver above." +"" +"" +"" +"" +"NG" +"Let us recall the last question in your lab activity. The inner side of" +"each kidney has a fissure or hilum for the entry of a renal artery" +"artery, exit of a" +"renal vein and an ureter.. Renal artery brings oxygenated blood loaded" +"with waste products and renal vein carries deoxygenated blood. The waste" +"products generated in various organs of the body are filtered and removed" +"by the kidneys." +"LA" +"posterior vena cava dorsal aorta" +"" +"" +"adrenal gland renal artery" +"TE" +"" +"left kidney" +"" +"" +"" +"renal vein" +"" +"left ureter" +"T" +"ER" +"" +"" +"" +"" +"opening of ureter" +"bladder into bladder" +"urethra" +"fig-3: Location of kidneys" +"external opening" +"fig-4: Excretory system" +"SC" +"" +"" +"" +"" +"Internal structure of the kidney:" +"Let us observe L.S of the kidney to know more about internal structure." +"It shows two distinct regions. Dark coloured outer zone called the cortex" +"and pale inner zone called medulla. Each kidney is made up of approximately" +"more than one million (1.3 to 1.8 million) microscopic and thin tubular" +"functional units called nephrons or uriniferous tubules." +"78 X Class Excretion The wastage disposing system" +" Structure of nephron" +"Each nephron has basically two parts. 1) Malpighian body and 2) Renal" +"tubule." +"" +"" +"" +"" +"A" +"Malpighian body: It consists of a blind cup shaped broader end of nephron" +"called Bowman’s capsule and bunch of fine blood capillaries called" +"" +"" +"" +"" +"AN" +"glomerulus. The Bowman’s capsule and glomerulus together called" +"malpighian capsule or renal capsule. Glomerulus develops from afferent" +"arteriole. It gives rise to an efferent arteriole." +"Think why the diameter of the efferent arteriole is less than that of" +"afferent arteriole?" +"" +"" +"" +"" +"NG" +"Because of the narrower out let (efferent arteriole) pressure exerts in" +"the glomerulus.It functions as a filtration unit. Bowmans capsule which" +"accommodates one glomerulus,is lined by a single layer of squamous" +"epithelial cells called podocyte cells. There are fine pores between" +"podocyte cells to allow passage of materials filtered out of glomerulus." +"LA afferent arteriole" +"malpighian body" +"efferent arteriole" +"" +"" +"cortex" +"glomerulus { Bowman’s capsule" +"first convoluted tubule" +"TE" +"" +"medulla" +"second convoluted" +"tubule" +"renal artery" +"renal vein" +"collecting duct" +"nephron ureter" +"loop of Henle" +"T" +"" +"" +"capillary network" +"calyces" +"pelvis" +"pelvis" +"open to pelvis" +"ER" +"" +"" +"" +"" +"fig-5: Internal structure of kidney" +"fig-6: Structure of a nephron" +"Renal tubule: It has three parts. First or proximal convoluted tubule (PCT)," +"loop of Henle, which is U shaped, second or distal convoluted tubule (DCT)." +"Distal convoluted tubules open into a collecting tube. Collecting tube" +"SC" +"" +"" +"" +"" +"form pyramids and calyces which open into the pelvis. Pelvis leads into" +"the ureter. All the parts of the renal tubule are covered by a network of" +"peritubular (around tube) capillaries formed from efferent arteriole. The" +"peritubular capillaries join to form renal venule, which joins the other" +"venules to form finally the renal vein." +"Why the nephron is considered to be the structural and functional" +"unit of the kidney?" +"Free distribution by T.S. Government 2019-20 79" +" Mechanisms of urine formation" +"Formation of urine involves four stages i. Glomerular filtration," +"" +"" +"" +"" +"A" +"ii.Tubular reabsorption, iii. Tubular secretion, iv.Concentration of urine" +"i) Glomerular filtration" +"" +"" +"" +"" +"AN" +"Blood flows from renal artery to glomerulus through afferent arteriole." +"Observe the fig-7 of glomerular filtration in nephron and try to answer the" +"following questions." +"Which arteriole has moree diameter, afferent or efferent?" +"What are the substances that are filtered into the glomerular capsule?" +"" +"" +"" +"" +"NG" +"ii) Tubular Re-absorption" +"Filtrate from glomerular is also called primary urine which almost equal" +"to blood in chemical composition except the presence of blood cells. It" +"passes into proximal convoluted tubule. Useful substances in primary urine" +"are reabsorbed into peritubular net work." +"LA" +"If you drink moree water will you pass more urine?" +"What are the substances reabsorbed into peritubular net work from" +"proximal convoluted tubule (PCT)?" +"iii) Tubular secretion" +"TE" +"" +"After reabsorption in PCT region, the urine travels through the loop" +"DCT. Here some other wastes like extra salts ions of K+ Na+" +"of Henle into DCT." +"Cl – and H+ secretes from peritubular capillaries in to DCT. It occurs mostly" +"in the distal convoluted tubule, which is also surrounded by peritubular" +"capillaries. This maintains a proper concentration and pH of the urine." +"T" +"" +"" +"Smaller amount of tubular secretion also takes place in the area of proximal" +"convoluted tubule. Observe tubular secretion in fig-7." +"ER" +"" +"" +"" +"" +"What are the substances that secretes into DCT?" +"" +"" +"Do you know?" +"After the age of 40 years the number of functioning nephrons usually decreases" +"SC" +"" +"" +"" +"" +"by about 10% in every 10 years." +"" +"iv) Formation of hypertonic Urine" +"75% of water content of nephric filtrate is reabsorbed in the region" +"of proximal convoluted tubule. 10% of water passes out of filtrate through" +"osmosis in the area of loop of Henle. Further concentration of urine takes" +"place in the area of collecting tubes in the presence of hormone called" +"80 X Class Excretion The wastage disposing system" +" i) Glomerular filtration: Blood flows inside the glomerulus ii)Tubular reabsorption:TheThe" +"under the influence of pressure due to the narrowness of peritubular capillaries around" +"efferent arteriole. As a result it undergoes pressure filtration PCT reabsorb all the useful" +"" +"" +"" +"" +"A" +"or ultra filtration. Waste molecules, nutrient molecules and components of primary urine" +"water are filtered out and enter the Bowman’s capsule. such as glucose, amino acids," +"vitamin C, Potassium, Calcium," +"" +"" +"" +"" +"AN" +"Sodium, Chlorides and 75% of" +"PCT Water." +"" +"glomerulus" +"DCT" +"" +"" +"" +"" +"NG" +"iii) Tubular secretion: It is" +"the active secretion of waste" +"products by blood capillaries" +"into the urinary tubule. It" +"ensures removal of all the" +"waste products from blood," +"viz., urea, uric acid, creatinine," +"LA salt ions like K+, Na+ and H+" +"ions. This maintance proper" +"concentration and pH of urine." +"" +"" +"fig-7: Mechanism of" +"TE" +"" +"urine formation" +"" +"" +"" +"vasopressin. The hormone is secreted only when concentrated urine is to" +"be passed out. Think why is it not secreted when a person drinks a lot of" +"water? Absence of vasopressin hormone produces dilute urine. Hormone" +"T" +"" +"" +"" +"action maintains osmotic concentration of body fluids. Deficiency of" +"vasopressin causes excessive, repeated, dilute urination called diabetes" +"ER" +"" +"" +"" +"" +"insipidus." +"Why more urine is produced in winter?" +"What happens if reabsorption of water does not takes place?" +"Now let us discuss remaining parts of excretory system." +"SC" +"" +"" +"" +"" +"2. Ureters" +"There are a pair of whitish, narrow distensible and muscular tubes of" +"30cm length. Each ureter arises from hilus of the kidney. It moves" +"downward and obliquely opens into the urinary bladder. Ureter carries urine" +"from the kidney to the urinary bladder. The movement of urine in the ureter" +"is through peristalysis." +"" +"Free distribution by T.S. Government 2019-20 81" +" 3. Urinary bladder" +"It is a median, pear shaped and distensible sac. It is situated in the" +"pelvic region on the ventral side of the rectum in the abdomen. It stores" +"" +"" +"" +"" +"A" +"urine brought by two ureters. The storage capacity of urinary bladder is" +"300 - 800ml." +"" +"" +"" +"" +"AN" +"4. Urethra" +"It is a tube that takes urine from urinary bladder to outside. The opening" +"of urinary bladder into urethra is guarded by a ring of muscles or sphincter." +"Urethra is 4 cm long in females open to vestibule and in males it is about" +"" +"" +"" +"" +"NG" +"20cm long. Its opening is separate in females but is in common with the" +"reproductive tract in males (urino-genital duct)." +"Micturition" +"The urine is temporarily stored in the bladder. There are two sets of" +"circular sphincter muscles in the bladder. When the bladder is filling up" +"LA" +"both these sets of muscles are constricted, so the exit is closed. However" +"as the pressure of the urine increases the walls of the bladder are stretched" +"and this triggers off an automatic reflex action which causes the upper" +"sphincter to relax. But the lower sphincter is under the control of brain." +"So urine can still be retained until this muscle is relaxed too. Control of" +"TE" +"" +"urination is not possessed by very young children but is gradually learned." +"Urge for micturition occurs when urinary bladder is filled with 300 -" +"400 ml of urine. The stretched bladder stimulates nerve endings to develop" +"the reflex. However, urine can be retained in the urinary bladder till it gets" +"filled up to the maximum capacity of 700 - 800ml. At this time the urge" +"T" +"" +"" +"becomes painful and leads to voluntary micturition. Total amount of urine" +"excreted per day is about 1.6-1.8 litres. It’s quantity increases with larger" +"ER" +"" +"" +"" +"" +"intake of fluids like water, fruit juices and decreases with lesser intake." +"" +"Think and discuss" +"" +"Do cells need excretion?" +"SC" +"" +"" +"" +"" +"Why we advised to take sufficient water?" +"Why do some children pass urine during sleep at night until 15 or 16 years of age?" +"Composition of urine" +"It is a transparent fluid produced by urinary system. Urine has amber" +"color due to presence of urochrome.Composition of normal urine varies" +"considerably depending on several factors for instance taking a protein" +"82 X Class Excretion The wastage disposing system" +" rich diet will result in more formation of urea in the urine. This is because" +"the proteins get de-aminated in the liver with subsequent formation of" +"urea. Even sugar can appear in a normal person after a heavy intake. If" +"" +"" +"" +"" +"A" +"other conditions are constant, a large intake of liquids or water - rich food" +"increases the volume of water in the blood, hence more urine is excreted." +"" +"" +"" +"" +"AN" +"Urine contains 96% of water 2.5% of organic substances (urea, uric" +"acid, creatine, creatinine, water soluble vitamins, hormones, and oxalates" +"etc) and 1.5% of inorganic solutes (sodium, chloride, phosphate, sulphate," +"magnesium, calcium, iodine). It is acidic (pH=6.0)in the beginning but" +"becomes alkaline on standing due to decomposition of urea to form" +"" +"" +"" +"" +"NG" +"ammonia." +"What happens if both kidneys fail completely?" +"Complete and irreversible kidney failure is called End Stage Renal" +"Disease (ESRD). If kidneys stop working completely, our body is filled" +"with extra water and waste products. This condition is called uremia. Our" +"LA" +"hands or feet may swell. You feel tired and weak because your body needs" +"clean blood to function properly. Is there any solution to this problem?" +"Let us know about artificial kidney." +"Dialysis Machine (Artificial kidney)" +"TE" +"" +"Kidneys are vital organs for survival. Several" +"factors like infections, injury, very high blood" +"pressure, very high blood sugar or restricted" +"blood flow to kidneys. This leads to accumulation" +"of poisonous wastes in the body and leads to" +"death. Dialysis machine is used to filter the blood" +"T" +"" +"" +"" +"of a person when both kidneys are damaged. The" +"process is called ‘haemodialysis’. In this process" +"ER" +"" +"" +"" +"" +"blood is taken out from the main artery, mixed fig-8: Dialysis" +"with an anticoagulant, such as heparin, and then" +"pumped into the apparatus called dialyzer. In this apparatus blood flows" +"through channels or tubes which are madeup of cellophane. These tubes" +"are embedded in the dialyzing fluid. The membrane separates the blood" +"SC" +"" +"" +"" +"" +"flowing inside the tube and dialyzing fluid (dialysis), which has the same" +"composition as that of plasma, except the nitrogenous wastes." +"As nitrogenous wastes are absent in dialyzing fluids, these substances" +"from the blood move out freely, there by cleaning the blood of its wastes." +"This process is called dialysis. This is similar to function of the kidney" +"but is different as there is no reabsorption involved .The cleaned blood is" +"pumped back to the body through a vein after adding anti-coagulant (heparin)." +"Free distribution by T.S. Government 2019-20 83" +" Each dialysis session lasts for 3 to 6 hours. This method has been using" +"for thousands of uremic / kidney failure patients all over the world." +"Is there any long term solution for kidney failure patients?" +"" +"" +"" +"" +"A" +"Do you know?" +"" +"" +"" +"" +"AN" +"The first kidney transplantation was performed between" +"identical twins in 1954 by Dr. Charles Hufnagel was a surgeon" +"at Washington, USA . In India first kidney transplantation was" +"done on 1st December 1971 at the Christian Medical college," +"Vellore, Tamilnadu." +"" +"" +"" +"" +"NG" +"Dr. Charles Hufnagel" +"" +"Kidney transplantation" +"The best long term solution for kidney failure (acute renal failure) is" +"Kidney transplantation. A functioning kidney is used in transplantation from" +"a donor preferably a close relative. The kidney that is received by a recipient" +"LA" +"must be a good match to his body, to minimize the chances of rejection of" +"transplanted kidney by the immune system of the recipient. Modern clinical" +"procedures have increased the success rate of such complicated technique." +"Where is the transplanted kidney fixed in the" +"TE" +"" +"body of a kidney failure patient?" +"What about the failed kidneys?" +"Can donor lead normal life with a single kid-" +"ney without any complications?" +"Now a days the process of organ donation helps" +"T" +"" +"" +"a lot for kidney failure patients. Organs are collected" +"fig-9: Kidney transplantation" +"from brain dead patients, then transplanted to the" +"ER" +"" +"" +"" +"" +"recepient. To know more about organ donation see in annexure." +"Other pathways of excretion ((accessory excretory organs)" +"You have learnt about kidney, chief excretory organ of our body." +"What are the other excretory organs of human body?" +"SC" +"" +"" +"" +"" +"Lungs, skin, liver have their own specific functions but carry out" +"excretion as a secondary function." +"Lungs: In respiratory process lungs remove carbon" +"dioxide and water." +"Skin: It consists of large number of sweat glands" +"richly supplied with blood capillaries, from which" +"fig-10: Lung, Skin they extract sweat and some metabolic wastes." +"84 X Class Excretion The wastage disposing system" +" Since the skin sends out plenty of water and small amount of salts, it serves" +"as an excretory organ. Sebaceous glands in skin eliminate sebum which" +"contains waxes, sterols, hydrocarbons and fatty acids." +"" +"" +"" +"" +"A" +"Collect information on sebum and prepare a news bulletin, display" +"it on bulletin board?" +"People in cold countries get very less/no sweat. What changes oc-" +"" +"" +"" +"" +"AN" +"cur in their skin and in other excretory organs?" +"Liver: It produces bile pigments (bilirubin ,biliverdin and urochrome)" +"which are metabolic wastes of haemoglobin of dead R.B.Cs. The life span" +"of RBC is 120 days. They are destroyed in the liver. Urochrome is" +"eliminated through urine. Biliverdin and bilirubin are excreted through" +"" +"" +"" +"" +"NG" +"bile along with cholesterol and derivatives of steroid hormones, extra drug," +"vitamins and alkaline salts. Liver is also involved in urea formation." +"Large intestine: Excess salts of calcium magnesium and iron are excreted" +"by epithelial cells of colon (large intestine) for elimination along with the" +"faeces." +"Small amount of nitrogenous wastes are also eliminated through saliva fig-11: Liver," +"and tears." +"LA intestine" +"Excretion in other organisms" +"Different organisms use varied strategies in excretion. Specific" +"excretory organs are absent in unicellular organisms. These organisms" +"TE" +"" +"remove waste products by simple diffusion from the body surface into the" +"surrounding water. Fresh water organisms like Amoeba, Paramoecium" +"possess osmoregulatory organelle called contractile vacuole. It collects" +"water and waste from the body, swells up, reaches the surface and bursts" +"to release its content to outside. The main excretion takes place through" +"body surface (Diffusion)." +"T" +"" +"" +"Table-4" +"Name of the phylum/ Excretory system/" +"ER" +"" +"" +"" +"" +"organism organ" +"Protozoa Simple diffusion from the body surface in to" +"the surrounding water" +"Porifera and coelenterates Water bathes almost all their cells" +"Platyhelminthes Flame cells" +"SC" +"" +"" +"" +"" +"Nematoda Renette cells" +"Annelids Nephridia" +"Arthropoda Green glands, Malpighian tubules" +"Mollusca Meta nephridia" +"Echinodermata Water vascular system" +"Reptiles, Aves and Mammals Kidneys" +"" +"Free distribution by T.S. Government 2019-20 85" +" Multicellular organisms possess different excretory organs for" +"removal of waste materials from the body. Structural and functional" +"complexity of excretory organs increases from sponges to humans." +"" +"" +"" +"" +"A" +"Sponges and coelenterates do not have specific excretory organs as water" +"bathes almost all their cells. Excretory structures appear for the first time" +"" +"" +"" +"" +"AN" +"in Flatworms (Platyhelminthes) are known as flame cells." +"Now let us see how this vital process takes place in plants" +"Excretion and release of substance in plants" +"Do plants excrete like animals?" +"" +"" +"" +"" +"NG" +"We are amazed to answer such type of questions. You are aware that a" +"variety of end products are formed during metabolism and these" +"nitrogenous wastes are important. Plants does not have specific organs to" +"excrete these wastes. Plants break down waste substances at much slower" +"rate than in animals. Hence accumulation of waste is also much slower." +"LA" +"Green plants in darkness and plants that do not possess chlorophyll produce" +"carbon dioxide and water as respiratory waste products. Oxygen itself can" +"be considered as a waste product generated during photosynthesis, that" +"exits out side through stomata of leaves and lenticels of stem." +"How do the plants manage or send out waste products from its body?" +"TE" +"" +"Plants can get rid of excess water by a process like transpiration and" +"guttation. Waste products may be stored in leaves, bark, and fruits. When" +"these dead leaves, bark, and ripe fruits fall off from the tree then waste" +"products in them are get rid off. Waste gets stored in the fruits in the form" +"of solid bodies called Raphides. However several compounds are" +"T" +"" +"" +"synthesized by the plants for their own use especially for defence. Many" +"plants synthesize chemicals and store them in roots, leaves, seeds, etc.," +"ER" +"" +"" +"" +"" +"for protection against herbivores. Most of the chemicals are unpleasant" +"to taste. Hence, herbivores usually do not prefer to eat such plants. Some" +"of the chemicals are toxic and may even kill the animal that eats them." +"" +"" +"Think and discuss" +"SC" +"" +"" +"" +"" +"Why are weeds and wild plants not affected by insects and pests?" +"" +"Some of the plants secrete chemicals when injured. These chemicals" +"seal the wound and help the plant to recover from an injury. Some of the" +"plants release attractants for other organisms which will help the plants" +"for pollination, seed dispersal or even in their nutrition. For example, plants" +"86 X Class Excretion The wastage disposing system" +" having root nodules secrete chemicals to attract rhizobia into the" +"surroundings of the roots and form a symbiotic relationship with the" +"rhizobium. These compounds are called secondary metabolites." +"" +"" +"" +"" +"A" +"Why plants shed their leaves and bark periodically?" +"The biochemical substances produced in plants are of two types," +"" +"" +"" +"" +"AN" +"primary metabolites and secondary metabolites. The materials like" +"carbohydrates, fats and proteins are primary metabolites. The materials" +"which do not require for normal growth and development are secondary" +"metabolites. e.g.: Alkaloids, Tannins, Resins, Gums, and Latex etc. Though" +"plants produce these chemical for their own use. Man found the usage of" +"" +"" +"" +"" +"NG" +"these chemicals for own benefits. They are generally coloured and fragrant." +"Alkaloids:" +"These are nitrogenous by- products and poisonous. These are stored" +"in different parts of the plants. Common alkaloids in plants and their uses" +"are given below." +"LA" +"Table-5" +"ALKALOID PLANT PART USES" +"Quinine Cinchona officinalis (Cinchona) Bark Antimalarial drug" +"TE" +"" +"Nicotine Nicotiana tobacum (Tobacco) Leaves Insecticide, stimulant" +"" +"Morphine, Cocaine Papaver somniferum (Opium) Fruit Pain killer" +"Reserpine Rauwolfia serpentina Root Medicine for" +"(Snake root) Snake bite,High BP" +"Caffeine Coffea arabica (Coffee plant) Seed Central nervous" +"T" +"" +"" +"" +"system Stimulant" +"Nimbin Azadirachta indica" +"indica(neem) Seeds, Barks, Leaves. Antiseptic" +"ER" +"" +"" +"" +"" +"Scopolamine Datura stramonium Fruit, flower Sedative" +"Pyrethroids Chrysanthemum sps Flower Insecticides" +"SC" +"" +"" +"" +"" +"Papaver Rauwolfia Coffea arabica Tobacco Datura" +"fig-12: Plants which produce Alkaloids" +"Name the alkaloids which are harmful to us?" +"Free distribution by T.S. Government 2019-20 87" +" Tannins:: Tannins are carbon compounds. These are stored in different" +"parts of the plant and are deep brown in colour. Tannins are used in tanning" +"of leather and in medicines e.g. Cassia, Acacia." +"" +"" +"" +"" +"A" +"Resin:: Occur mostly in Gymnosperms in specialized passages called resin" +"passages. These are used in varnishes- e.g.Pinus." +"" +"" +"" +"" +"AN" +"NG" +"fig-13(a): Cassia fig-13(b): Acacia fig-13(c): Pinus" +"Gums:: Plants like Neem, Acacia oozes out a sticky substance called gum" +"LA" +"when branches are cut. The gum swells by absorbing water and helps in the" +"healing of damaged parts of a plant. Gums are economically valuable and" +"used as adhesives and binding agents, in the preparation of the medicines," +"food, etc." +"TE" +"" +"Latex:: Latex is a sticky, milky white substance secreted by plants. Latex" +"is stored in latex cells or latex vessels. From the latex of Hevea" +"braziliensis (Rubber plant) rubber is prepared. Latex from Jatropa is the" +"source of bio-diesel. Do you know which part of jatropa used in production" +"of bio diesel." +"T" +"ER" +"SC" +"" +"" +"" +"" +"fig-14(a): Neem fig-14(b): Jatropa fig-14(c): Rubber plant" +"" +"Do you know?" +"Chewing gum is a type of sticky for chewing made dates back 5000 years. Modern" +"chewing gum originally made of natural latex from plants like chicle, sapota etc." +"Whenever pollen grains enter in our body they cause allergy due to the presence of" +"nitrogenous substances. These allergens cause skin allergy and asthma. Ex: Parthenium." +"" +"88 X Class Excretion The wastage disposing system" +" Do roots secrete?" +"‘Brugman’ a botanist proved from his experiments that the roots not" +"only absorb fluid from soil, but returns a portion of their peculiar secretions" +"" +"" +"" +"" +"A" +"back into it. We can see such instances in plants like apple where a single" +"apple crop for 4 or 5 years continuously in the same soil, that fail to produce" +"" +"" +"" +"" +"AN" +"fruits. It will not give proper yield even if you use lot of fertilizers." +"Do you think there is any relation between reduction in yielding" +"and root secretions?" +"Why do we get peculiar smell when you shift the potted plants?" +"" +"" +"" +"" +"NG" +"Excretion Vs Secretion" +"Excretion and secretion are the same in nature. Since both are involved" +"in passage or movement of materials. Both processes move and eliminate" +"unwanted components from the body. Excretion is the removal of materials" +"from a living being, while secretion is movement of material from one" +"LA" +"point to other point. So secretion is active while excretion is passive in" +"nature. Humans excrete materials such as tears, urine, Carbon dioxide," +"and sweat while secretion on other hand, includes enzymes, hormones," +"and saliva. In plants too we find excretion through roots into its surroundings" +"and falling off leaves and bark. Secretions occur in the plant body in form" +"TE" +"" +"of latex, resins, gums etc." +"" +"" +"Key words" +"Creatinine, tubular fluid, peritubular network, podocyte, glomerulus, PCT, DCT," +"T" +"" +"" +"afferent arteriole, efferent arteriole, calyces, micturation, urochrome, dialyser," +"heamodialysis, anticoagulant, alkoloid, biodiesel, loop of henle." +"ER" +"" +"" +"" +"" +"What we have learnt" +"" +"Due to metabolism several harmful excretory products are formed and process of removing toxic" +"waste from the body is called execretion." +"SC" +"" +"" +"" +"" +"The human excretory system comprises a pair of kidneys, a pair of ureters, urinary bladder, urethra." +"Each kidney is composed of approximately 1.3 to 1.8 millions of uriniferous tubules or nephrons," +"which are structural and functional units of kidney." +"A nephron comprises glomerulus,bowman’s capsule, proximal convoluted tubule (PCT), Henle’s" +"loop, Distal convoluted tubule (DCT) and collecting tubule." +"Formation of urine involves four stages. 1) Glomerular filteration, 2) Tubular Reabsorption," +"3) Tubular Secretion, 4) Concentration of Urine." +"Free distribution by T.S. Government 2019-20 89" +" Kidneys remove nitrogenous waste from body, maintains water balance (osmoregulation), salt" +"content, pH, and blood pressure in human body." +"Dialysis machine is an artificial kidney which filters the blood to remove the metabolic wastes out" +"" +"" +"" +"" +"A" +"side the body." +"Kidney transplantation is a permanent solution to renal failure patients." +"" +"" +"" +"" +"AN" +"Different animals have different excretory organs e.g. amoeba-contractile vacuole, platyhelminthes-" +"flame cells, annelida-nephridia, arthropoda-malpighian tubule, reptiles, birds and mammals-kidney." +"There are no special organs for excretion in plants. Plants store different waste materials in leaves," +"bark, roots, seeds which fall of from the plants." +"Plant metabolites are two types i) primary metabolites eg: proteins carbohydrates and fats." +"ii) secondary metabolites eg: alkoloids, gums, tannins, latex and resins. These are economically important" +"" +"" +"" +"" +"NG" +"to us." +"Excretion is the removal of material from living beings where as secretion is movement of materials" +"from one point to other." +"" +"Improve your learning LA" +"1. What is meant by excretion? Explain the process of formation of urine. (AS1)" +"2. How are waste products excreted in amoeba?(AS1)" +"3. Name different excretory organs in human body and excretory material generated by them?(AS1)" +"4. Deepak said that ‘Nephrons are functional and structural units of kidneys’ how will you support" +"him?(AS1)" +"TE" +"" +"5. How plants manage the waste materials?(AS1)" +"6. Why do some people need to use a dialysis machine? Explain the principle involved in it.(AS1)" +"7. What is meant by osmoregulation? How is it maintained in human body?(AS1)" +"8. Do you find any relationship between circulatory system and excretory system? What are they?(AS1)" +"9. Give reasons(AS1)" +"A.Always vasopressin is not secreted." +"T" +"" +"" +"" +"B.When urine is discharged, in beginning it is acidic in nature later it become alkaline." +"C. Diameter of afferent arteriole is bigger than efferent arteriole." +"ER" +"" +"" +"" +"" +"D.Urine is slightly thicker in summer than in winter?" +"10. Write differences(AS1)" +"A. Functions of PCT and DCT B. Kidney and artificial kidney" +"C. Excretion and secretion D. Primary metabolites and secondary metabolites" +"11. There is a pair of bean-shaped organs ‘P’ in the human body towards the back, just above the" +"waist. A waste product ‘Q’ formed by the decomposition of unused proteins in liver is brought into" +"SC" +"" +"" +"" +"" +"organ ‘P’ through blood by an artery ‘R’. The numerous tiny filters ‘S’ present in organ ‘P’ clean" +"the dirty blood goes into circulation through a vein ‘T’. The waste substance ‘Q’ and other waste" +"salts and excess water form a yellowish liquid ‘U’ which goes from organ ‘P’ into a bag like" +"structure ‘V’ through two tubes ‘W’. This liquid is then thrown out of the body through a tube" +"‘X’.(AS1)" +"(a) What is (i) organ P and (ii) waste substance Q." +"(b) Name (i) artery R and (ii) vein T" +"" +"90 X Class Excretion The wastage disposing system" +" (c) What are tiny filters S known as?" +"(d) Name (i) liquid U (ii) structure V (iii) tubes W (iv) tube X." +"12. The organ ‘A’ of a person has been damaged completely due to a poisonous waste material ‘B’" +"" +"" +"" +"" +"A" +"has started accumulation in his blood, making it dirty. In order to save this person’s life, the blood" +"from an artery in the person’s arm is made to flow into long tubes made of substance ‘E’ which are" +"kept in coiled form in a tank containing solution ‘F’. This solution contains three materials ‘G’, ‘H’" +"" +"" +"" +"" +"AN" +"and ‘I’ similar proportions to those in normal blood. As the person’s blood passes through long" +"tubes of substance ‘E’, most if the wastes present in it go into solution ‘F’. The clean blood is then" +"put back into a vein in the person for circulation. (AS1)" +"(a) What is organ A?" +"(b) Name the wastes substance B." +"" +"" +"" +"" +"NG" +"(c) What are (i) E, and (ii) F?" +"(d) What are G, H and I?" +"(e) What is the process described above known as?" +"13. Imagine what happens if waste materials are not sent out of the body from time to time?(AS2)" +"14. To keep your kidneys healthy for long period what questions will you ask a nephrologist/" +"urologist?(AS2)" +"15" +"LA" +"What are the gum yielding trees in your surroundings? What procedure you should follow to" +"collect gum from trees?(AS3)" +"16. Collect the information about uses of different kinds alkaloids, take help of Library or internet?(AS4)" +"17. Draw a neat labeled diagram of L.S of kidney?(AS5)" +"18. Describe the structure of nephron with the help of a daigram. (AS5)" +"TE" +"" +"19. Draw a block daigram showing the path way of excretory system in human beings. (AS5)" +"20. If you want to explain the process of filtration in kidney what diagram you need to draw.(AS5)" +"21. List out the things that makes you amazing in excretory system of human being.(AS6)" +"22. You read about ‘Brain dead’ in this chapter. What discussions would you like to have why you" +"think so?(AS6)" +"T" +"" +"" +"23. We people have very less awareness about organ donation, to motivate people write slogans" +"about organ donation?(AS7)" +"24. After learning this chapter what habits you would like to change or follow for proper functioning of" +"ER" +"" +"" +"" +"" +"kidneys?(AS7)" +"" +"Fill in the blanks" +"" +"1. Earthworm excretes it’s waste material through ______________." +"SC" +"" +"" +"" +"" +"2. The dark coloured outer zone of kidney is called _____________." +"3. The process of control of water balance and ion concentration with in organism is called________." +"4. Reabsorption of useful product takes place in ____________ part of nephron." +"5. Gums and resins are the __________ products of the plants." +"6. Bowman’s capsule and tubule taken together make a ___________." +"7. The alkaloid used for malaria treatment is ________________." +"" +"Free distribution by T.S. Government 2019-20 91" +" 8. The principle involved in dialysis is __________________." +"9. Rubber is produced from ______________ of Heavea braziliensis." +"10. ________________ performed first Kidney Transplantation." +"" +"" +"" +"" +"A" +"Choose the correct answer" +"" +"" +"" +"" +"AN" +"11. The structural and functional unit of human kidney is called ( )" +"(A) Neuron (B)nephron" +")nephron (C)nephridia (D)flame cell" +"(D)flame" +"12. The excretory organ in cockroch ( )" +"" +"" +"" +"" +"NG" +"(A) malpighian tubules (B) raphids (C) ureters (D) nephridia" +"13. Which of the following is the correct path taken by urine in our body? ( )" +"(i) Kidneys (ii) Ureters (iii) Urethra (iv) Urinary bladder" +"(A) i, ii, iv, iii (B) i, ii, iii, iv" +"(c) iv, iii, i, ii (D) ii, iii, i, iv" +"LA" +"14. Malpighian tubes are excretory organs in ( )" +"(A) earth worm (B) house fly (C) flat worm (D) hen" +"15. Major component of urine is ( )" +"(A) urea (B) sodium (C) water (D) creatine" +"16. Special excretory organs are absent in ( )" +"TE" +"" +"(A) birds (B) amoeba (C) sponges (D) a and b" +"17. Which of the following hormone has direct impact on urination? ( )" +"(A) adrenal (B) vasopressin (C) testosterone (D) Oestrogen" +"18. Amber colour to urine due to ( )" +"(A) urochrome ( B) bilirubin (C) biliverdin (D) chlorides" +"T" +"" +"" +"19. Sequence of urine formation in nephron is ( )" +"(A)Glomerular filtration Tubular reabsorption Tubular secretion" +"ER" +"" +"" +"" +"" +"(B)Tubular reabsorption Tubular secretion Glomerular filtration" +"(C)Tubular secretion Glomerular filtration Tubular reabsorption" +"(D)Tubular reabsorption concentration of urine Tubular secretion" +"20. Part of the nephron that exists in outer zone of kidney. ( )" +"A) Loop of the henle B) PCT C) DCT D) Bowman’s capsule" +"SC" +"" +"" +"" +"" +"21. After having lunch or dinner one can feel to pass urine, because of a ( )" +"A) stomach pressures on bladder B) solids become liquids" +"C) water content in food material D) spincter relaxation" +"" +"" +"" +"" +"92 X Class Excretion The wastage disposing system" +" We can live even after death" +"Annexure" +"Five organs of 18 year old" +"" +"" +"" +"" +"A" +"Organ donation - A gift for life youth donated" +"So many patients are waiting for suitable organ DC correspondent, Hyderabad," +"" +"" +"" +"" +"AN" +"due to failure of vital organs. In Hyderabad where there 20 June 2013" +"are kidney transplantation facilities minimum 25 Five organs of 18 year old" +"patients per hospital are waiting for kidney donors. H.S. YASWANTH KUMAR were" +"Daily 10 - 100 people met with accident in our State. donated by his father H V Shiva" +"Out of them some people get brain dead. If we collect Kumar to the organ donation wing" +"" +"" +"" +"" +"NG" +"organs from brain dead patients in time, we can save of Jeevandan scheme on Thursday." +"minimum 5 peoples’ life. But lack of awareness on Yaswanth had met an accident on" +"organ donation those who are willing to donate organs June 15 while he was travelling in" +"and those who need organs do not get proper" +"a shared autorikshaw from" +"information even facilities are there. Medical" +"Jagadgirigutta. He was rushed to" +"personnels from government and private hospitals are" +"LA" +"not informing about brain dead Patients. If they inform" +"Nizam Institute of Medical" +"in appropriate time it will be very useful to patients Sciences (NIMS).The Neuro" +"those who are waiting for organ donation. In surgeons at NIMS declared him" +"Hyderabad, organ Transplantation facility is available brain dead. Jeevandan counsellors" +"only in two government hospitals (NIMS and obtained the consent of Mr. Shiva" +"TE" +"" +"Osmonia) and in more than 10 corporate hospitals. Kumar,who agreed to donate" +"Other organs like cornea transplant organs like Yaswanth’s kidneys, two heart" +"kidney, liver, heart, lungs, pancreas, skin, bone, valves, liver. These organs were" +"intestines and eye (cornea) can transplanted from retrieved and sent to various" +"brain dead patients.The process of transplantation of hospitals for transplantaion." +"T" +"" +"" +"organs from brain dead patients to another is called Dr. Swarnalatha in-charge of" +"cadaver transplantation. IIff any person is willing to Jeevandan scheme, said in a" +"donate organs or in needy get organs. They must" +"ER" +"" +"" +"" +"" +"statement. Think how great" +"register their names in transplantation facility Yaswanth’s parents are?" +"hospitals." +"Collect information about a voluntary" +"organisation working on organ donation and make a" +"report." +"SC" +"" +"" +"" +"" +"There is very less awareness among people about" +"organ donation. Society needs much awareness in" +"organ donation, so that we can save many lives who" +"are in need of different organs from donars for their" +"survival. Instead of living in their memories, let us" +"give them a chance to live in others for one more life." +"" +"" +"Free distribution by T.S. Government 2019-20 93" +" A" +"Chapter" +"" +"" +"" +"" +"AN" +"5" +"" +"" +"NG" +"Co ordination - The linking system" +"" +"Sharpening of a pencil, grasping a door knob, walking or running," +"LA" +"driving, and a few physical actions, all involve well coordinated movements" +"made with well balanced postures. In fact, whenever we move the three" +"basic functions, such as movement, balance and coordination work together" +"to perform purposeful motions of body parts. This is actually quite a feat," +"because moving is a complex process for the body." +"TE" +"" +"Even standing upright is a difficult challenge of balancing on just two" +"feet with a narrow base. Yet, it is common for us not only to stand upright" +"easily and apparently, effortlessly, but also while keeping our balance to" +"perform many other functions." +"What other functions do you think needed in coordination and" +"T" +"" +"" +"" +"balance?" +"All our functions are carried out by an effort of several systems" +"ER" +"" +"" +"" +"" +"working together. For example, while movement, we hardly ever use just" +"the skeletal system or muscular system alone, several other systems also" +"have their own roles to play. Even within the muscular system, several" +"muscles work in a sequence or at once." +"SC" +"" +"" +"" +"" +"What triggers movement of the muscles?" +"All our body organs, tissues and cells work together systematically." +"All of them pick up signals of change from their surroundings and respond" +"to them. This process triggers different functions in our body as well as" +"by our body. For example, it is natural to move to a side of the road when" +"we hear or see a car approaching." +"How do we respond so fast according to situation?" +"94 X Class Coordination - The liking system" +" Responding to stimuli" +"What helps us to respond to such signals?" +"" +"" +"" +"" +"A" +"Why does the living body respond to such signals?" +"We can think of a response as an effect of a change in the environment" +"" +"" +"" +"" +"AN" +"of the organism or signals of change or ‘stimuli’.All living organisms" +"respond to stimuli. The cat may be running because it saw a mouse. Plants" +"grow towards the sunlight. We start sweating when it is hot and humid." +"The ability to react to particular stimulus in a particular situation must" +"be of great importance in ensuring the survival of the organism." +"" +"" +"" +"" +"NG" +"There is a sequence of events that brings about responses. They start" +"from detecting changes in environment (both external and internal) or" +"stimuli, transmission of the information, processing of the same. Finally" +"the response will detect and execute the appropriate action." +"Let us do the following activity to find more about response to stimuli." +"LA" +"Activity-1" +"Holding a falling stick" +"Take a long scale or stick at least around ½ meter. Keep your" +"TE" +"" +"fingers in holding position as shown in fig-1 . Ask your friend to" +"hold the stick / scale near the end and let the other end be" +"suspended between your fingers." +"Let there be a very small gap around a centimeter between" +"your thumb and stick/scale and the stick/scale and fore finger." +"Now let your friend allow it to fall. Try to hold it." +"T" +"" +"" +"" +"Could you hold it exactly at the point where it was" +"suspended between your fingers?" +"ER" +"" +"" +"" +"" +"fig-1: Holding stick" +"Mark the point where you caught the stick." +"How far up was this point from the end suspended between your fingers?" +"Why did this happen?" +"How fast do you think the process was?" +"SC" +"" +"" +"" +"" +"Responses are brought about by rapid changes in some muscles and" +"such changes are usually related to changing stimuli. Rapidity of response" +"indicates an efficient communication system linking those parts that pick" +"up stimuli to those that trigger a response." +"What makes this kind of communication possible?" +"" +"Free distribution by T.S. Government 2019-20 95" +" Integrating pathways - Nervous coordination" +"The Greeks believed that all functions of the body were controlled by" +"" +"" +"" +"" +"A" +"the brain since damage to that organ produced remarkable changes in" +"behaviour. They had very little idea on how such control could be exercised" +"Though Galen, a Greek physiologist (A.D. 129-200) made one notable" +"" +"" +"" +"" +"AN" +"observation. One of his patients, having suffered a blow on the neck when" +"falling from his chariot, complained loss of feeling in the arm while still" +"fig-2: Galen retaining normal muscular control of its moment. Galen concluded that" +"nerves were of two kinds – those of sensation and those of action." +"According to him the blow in the neck had damaged the nerves of sensation" +"" +"" +"" +"" +"NG" +"but had not affected it’s action." +"Why do you think Galen draw such a conclusion?" +"The functioning of nerves as integrating systems was little known till" +"late 18th century. Then, physiologists began to study the mechanism of" +"nerve functioning and found how signals were transmitted by making the" +"LA" +"connection between recent work on electricity and the propositions on" +"working of the nervous system made till then." +"Now we know more about how nerves from different sections of the" +"brain and spinal cord control responses of different areas of the body. We" +"TE" +"" +"also know the probable pathways that transmit information but we still" +"know very little about the working mechanisms of the nerve cell." +"Structure of nerve cell" +"" +"Activity-2" +"T" +"" +"" +"" +"Observe the permanent slide of nerve cell or neuron under microscope" +"draw and label its parts, compare with the following diagram." +"ER" +"" +"" +"" +"" +"dendrites Each nerve cell consists of a cell body with" +"nissl’s granules a prominent nucleus. There are fine projections" +"nucleus mainly of two types extending from the cell body" +"cell body of the nerve cell. The small projections are" +"dendrites while a long one that extends to" +"SC" +"" +"" +"" +"" +"schwann cell" +"different parts of our body is called Axon. The" +"fig-3: axon axon is surrounded by a specialized insulatory" +"Nerve cell node of ranvier sheath called myelin sheath.This sheath is" +"myelin sheath interrupted at regular intervals called nodes of" +"synaptic knob ranvier.The myelin sheath is made up of schwann" +"cells and chiefly consists of fatty material." +"axon terminal Axons not having the sheath are non-myelinated" +"96 X Class Coordination - The liking system" +" fibers. The covering also forms a partition between adjacent axons. The" +"nerve cell body lies either in our brain or spinal cord or very close to the" +"spinal cord in a region called dorsal or ventral root ganglion. In the brain" +"" +"" +"" +"" +"A" +"or spinal cord, it is difficult to make out the difference between dendrites" +"and axons on the basis of their length, often, the presence of the sheath" +"" +"" +"" +"" +"AN" +"helps us to find out but several axons here do not have the sheath." +"We know that the nerve cell is the structural and" +"functional unit of nervous system. Our nervous system" +"consists of more than100 billion of them, which" +"communicate with each other in a specific manner." +"" +"" +"" +"" +"NG" +"Synapse" +"" +"Dendrites of one nerve cell connect to the other or" +"to the axons of the other nerve cell through" +"connections called as a ‘synapse’." +"Synapse is the functional region of contact" +"between two neurons, where information from one" +"LA" +"neuron is transmitted or relayed to another neuron. fig-4: Synapse" +"Though these are regions of minute gaps and essentially neurons do not" +"have any protoplasmic connection between them yet information is passed" +"from one nerve cell to the other through these gaps either in the form of" +"TE" +"" +"chemical or electrical signals or both. These synapses are mainly found" +"on the brain, spinal cord and around the spinal cord. Beyond these areas" +"the axon carries the signals to respective areas in our body." +"Pathways: From stimulus to response" +"In the holding stick activity you observed that there is coordination" +"between eye and finger. Different pathways are taken by nerves to bring" +"T" +"" +"" +"" +"about this coordinated activity." +"On the basis of pathways followed, nerves are classified mainly into" +"ER" +"" +"" +"" +"" +"three different types. They are as follows." +"Afferent nerves or Sensory nerves :" +"(a) Afferent (or ferrying towards) which carry messages towards the" +"central nervous system (spinal cord or brain) from nerve endings on the" +"SC" +"" +"" +"" +"" +"muscles of different sense organs that sense the change in surroundings" +"are called stimulus detectors. These are also called ‘sensory’ nerves." +"" +"" +"" +"" +"fig-5: Sensory neuron" +"" +"Free distribution by T.S. Government 2019-20 97" +" (b) Efferent nerves or motor nerves :" +"Efferent (or ferrying away) which carry messages from the central" +"nervous system to parts that shall carry out the response or the effectors" +"" +"" +"" +"" +"A" +"(muscles). They are also called ‘motor’ nerves." +"" +"" +"" +"" +"AN" +"fig-6: motor neuron" +"(c) Association nerves:" +"Association nerves, which link together the afferent and efferent" +"" +"" +"" +"" +"NG" +"nerves." +"gan of your body was the detector and which the effector" +"Which organ" +"in Activity-1?" +"What do you think that the information carried on the afferent and" +"LA" +"efferent nerves?" +"Activity-1 showed a" +"Brain or" +"spinal cord response on which you had some" +"control or it was voluntary" +"(recall the use of the voluntary" +"TE" +"" +"Afferent Efferent" +"and involuntary muscles that you" +"Association" +"nerves nerves nerves studied in class 9th.). We know" +"that our body would also need to" +"respond to certain situations on" +"which we may not have a control." +"Muscles of" +"T" +"" +"" +"Sense" +"organs the organ Such responses are called" +"reflexes.A simple activity shall" +"ER" +"" +"" +"" +"" +"fig-7: Different nerve pathways help us to understand this better." +"" +"Activity-3" +"Knee jerk reflex" +"Cross the legs, in a seated position, so that the lower" +"SC" +"" +"" +"" +"" +"half of the uppermost leg hangs freely over the other. Strike" +"the area below the knee cap sharply, while firmly grasping" +"the front part of the thigh with the other hand. Note the" +"changes in shape of the thigh muscles." +"Note that although we are fully conscious, we cannot" +"prevent the thigh muscles from contracting. Such a response" +"fig-8: Knee jerk" +"98 X Class Coordination - The liking system" +" is said to be involuntary. Now the same thigh muscle can operate in a" +"voluntary manner, as when we kick a football." +"Do you think most of the functions in our body go about in an" +"" +"" +"" +"" +"A" +"involuntary manner? Why /Why not?" +"" +"" +"" +"" +"AN" +"Do you know ?" +"The existence of the knee jerk was first noted in 1875. At first it was doubted" +"whether a nervous reflex was involved at all. But it was discovered that if, in an" +"anaesthetized monkey where spinal nerves supplying the limb were cut, the knee jerk" +"reaction would not occur. Clearly a nerve pathway was involved." +"" +"" +"" +"" +"NG" +"During actions which are involuntary and have to be carried out in very" +"short intervals of time, the pathway that nerves follow is a short one; it" +"does not go up to the brain while voluntary pathways are usually longer" +"passing through the brain. Now let us see what pathways actually are." +"The reflex arc" +"LA" +"Not until the end of the inter neuron" +"nineteenth century the reflex was spinal cord" +"understood in terms of pathways." +"TE" +"" +"sensory nerve" +"Picking up information of a" +"stimulus to generate a response motor nerve" +"involves a pathway from detectors effector muscle" +"to brain or spinal cord or a set of" +"nerve cell heads near spinal cord" +"to the effectors. Such a single" +"T" +"" +"" +"" +"pathway going upto the spinal detector" +"cord from detectors and returning" +"ER" +"" +"" +"" +"" +"fig-9: Reflex arc" +"to effectors is a reflex arc." +"If you accidentally touch a very sharp surface with your feet, several" +"such arcs would operate to cause the muscles of the leg to withdraw the" +"feet. Observe the fig-9, how our leg muscle responds when we step on a" +"sharp edged object." +"SC" +"" +"" +"" +"" +"What other effectors would act under these circumstances?" +"What does this tell us about the association of nerves?" +"In fact, you must have experienced, what happens when you do things" +"consciously and otherwise. Say for example, when you are performing an" +"action such as running upstairs. If you start to think about where your feet" +"are going you often stumble. The interesting thing is that the same effectors" +"Free distribution by T.S. Government 2019-20 99" +" in the leg muscles can be made to perform very special movement under the control of the" +"conscious mind (voluntarily). Hence in a football game, the muscles of the leg operate" +"both by reflexes and voluntarily. Most actions of our body are actually controlled together" +"" +"" +"" +"" +"A" +"by voluntary and involuntary pathways." +"" +"Do you know ?" +"" +"" +"" +"" +"AN" +"Nerve transmission from stimulus to a response can occur at a maximum speed of" +"about 100 meters per second." +"Shrews (tiny rat) have the highest, brain to body mass ratio." +"Think of any action and try to make a sketch of the reflex arc." +"" +"" +"" +"" +"NG" +"The voluntary and involuntary actions in our body are controlled by nervous system as" +"a whole.We may study our nervous system on the basis of areas from which nerves originate" +"and then spread out to the whole body as mainly two divisions one is the central nervous" +"system (CNS) and the other is peripheral nervous system (PNS)" +"Central Nervous System (CNS)" +"LA" +"Central nervous system includes brain and spinal cord. It coordinates all neural functions." +"Brain" +"When compare to body weight human brain is the largest of all the animals. The brain is" +"TE" +"" +"present in the hard bony box like structure called cranium. It is covered by three layers" +"called the meninges. The meninges are continuous and cover the spinal cord as well. The" +"space between the inner layers is filled with fluid called cerebro-spinal fluid. It serves as a" +"shock-absorbing medium and protects the brain against shocks/jerks along with the meninges" +"and cranium. Mainly the nerve cell bodies together with capillaries form a mass called" +"T" +"" +"" +"grey matter while the myelinated axons or those covered by fatty sheaths form white matter." +"The grey matter is usually present on the periphery while white matter is present towards" +"ER" +"" +"" +"" +"" +"the center. This is mainly due to the fact that there is a small area from where the myelinated" +"axons leave the brain. As we have already" +"cerebrum" +"studied, the function of the brain as a" +"control center was known nearly 2000" +"Corpus collosum years back by Greek physiologists." +"SC" +"" +"" +"" +"" +"Diencephalon Brain has the following divisions –" +"pons varolii 1. Forebrain – cerebrum," +"cerebellum diencephalon" +"pituitary gland" +"2. Midbrain – optic lobes" +"spinal cord" +"medulla 3. Hindbrain – cerebellum, medulla" +"oblongata" +"fig-10: Brain oblongata." +"" +"100 X Class Coordination - The liking system" +" Table - 1 : Let us study the functions of the various parts of the brain" +"Fore brain" +"" +"" +"" +"" +"A" +"Olfactory lobes : These clubshaped widely spread bodies are visible from the ventral" +"surface only." +"Functions : These are concerned with sense of smell." +"" +"" +"" +"" +"AN" +"Cerebrum : It consists of two lobes called cerebral hemispheres. The surface of the" +"cerebrum has many folds, they appear as elevations (Gyri) and depressions (Sulci). Sulci" +"are very prominent and divide each hemisphere into four lobes." +"l ask your teacher the name of those lobes." +"" +"" +"" +"" +"NG" +"l observe the fig. 10 which part connects the two hemispheres ?" +"" +"" +"Functions : i) Seat of mental abilities, controls thinking, memory, reasoning, perception," +"emotions and speech." +"ii) Interprets sensations and responds to cold, heat, pain and pressure." +"Diencephalon : This rhomboidal shaped lobe visible from inferior surface of brain. It lies" +"LA" +"between cerebrum and mid brain. It is divided into thalamus and hypothalamus (Master" +"control centre of endocrine system). Where as Pituatory gland is called Master gland." +"Functions : i) Relay centre for sensory impulses, such as pain, temperature and light." +"ii) Reflex centre for muscular activities." +"iii) Centre for certain emotions such as anger." +"TE" +"" +"iv) Centre for water balance, blood pressure, body temperature, sleep and hunger." +"v) The hypothalamus controls the pituitary gland, which functions as the" +"master gland." +"Mid-brain : This is a small thick stalked portion. This connects forebrain with cerebellum" +"and pons of hind brain." +"T" +"" +"" +"l observe optic lobes of mid brain in the brain model in your laboratory." +"" +"l observe the fig. 10 which part connects the two hemispheres ?" +"ER" +"" +"" +"" +"" +"Functions : It relays motor impulses from the cerebral cortex to the spinal cord and relays" +"sensory impulses from the spinal cord to the thalamus, reflexes for sight and hearing." +"Hind brain : This is the last part of the brain consists of cerebellum, medulla oblongata." +"Cerebellum : It is located below the cerebrum and above medulla oblongata. It consists" +"of two large cerebellar hemispheres." +"SC" +"" +"" +"" +"" +"Functions : i) Maintains posture, equilibrium and muscle tone." +"ii) Coordinates voluntary movements initiated by cerebrum." +"Medulla oblongata : It is almost triangular shaped. Medulla oblongata extends from pons" +"to spinal cord. Ask your teacher grey and white matters of medulla oblongata" +"Functions : i) Contains centre for cardiac, respiratory and vasomotor activities." +"(Vasomotor refers to actions upon a blood vessel which alter its diameter)" +"ii) Coordinates reflexes like swallowing, coughing, sneezing and vomiting." +"Free distribution by T.S. Government 2019-20 101" +" Do you know ?" +"The brain weighs approximately 1400g. Though the brain comprises little more" +"" +"" +"" +"" +"A" +"than 2% the body’s weight, it uses 20% of the whole body energy." +"An average adult male brain weighs about 1375g and female 1275g." +"" +"" +"" +"" +"AN" +"Spinal Cord" +"Spinal cord extends from the back of the hind brain(Medulla" +"oblongata) to the back of the stomach or lumbar region, through the neural" +"canal of the vertebral column. It is almost cylindrical in shape. Unlike" +"" +"" +"" +"" +"NG" +"the brain, the white matter is towards periphery while grey matter is" +"towards the center of the spinal cord. The myelinated axons leave the" +"spinal cord from both sides of the vertebral column. See fig-11." +"The role of the spinal cord in nervous control was studied largely by" +"fig-11: Spinal" +"the experimentalists of the sixteenth and seventeenth centuries. They" +"cord" +"found that the Greeks concept of control by the brain was erroneous." +"LA" +"Animals were shown to have the ability to respond to stimuli even when" +"the brain was removed. ‘Leonardo da Vinci’ (1452-1519) and ‘Stephen" +"Hales’ (1677-1771) both recorded the survival of frogs whose brain had" +"been destroyed. The animal still produced muscular movements if its" +"TE" +"" +"skin was pinched or pricked. Both observers further recorded that the" +"animal died as soon as spinal cord was damaged by pushing a needle" +"down it." +"fig-12: Leonardo Such evidence suggested that the spinal cord was not simply a trunk" +"da vinci road for instructions from the brain, but might be a control center in its" +"own right." +"T" +"" +"" +"" +"According to you what would be the function of the spinal cord?" +"Are all functions of our body under direct control of the brain and spinal cord? Why" +"ER" +"" +"" +"" +"" +"do you think so?" +"Do you know ?" +"Scientists have been able to trace out the nerves that originate from brain called" +"cranial nerves and those that originate from spinal cord called spinal nerves. There" +"SC" +"" +"" +"" +"" +"are 12 pairs of cranial nerves which arise from the brain. There are 31 pairs of spinal" +"nerves." +"" +"Peripheral nervous system" +"Figure-13 shows you that nerves attached to the spinal cord have two" +"types of connections or roots – One to the back or dorsal side and other to" +"front or the ventral side of cord. The experimental work of two men, Charles" +"102 X Class Coordination - The liking system" +" Bell in Scotland and Francois Magendie" +"dorsal root" +"in France, in the early nineteenth dorsal root" +"dorsal horn" +"century, showed that these roots have ganglion" +"" +"" +"" +"" +"A" +"different functions. If the dorsal roots" +"of an experimental animal were cut the" +"" +"" +"" +"" +"AN" +"animal made no obvious reaction. If," +"however, the ventral roots were even" +"lightly touched, the muscles to which" +"the nerve was connected switched ventral horn spinal nerve" +"violently. The ventral root evidently ventral root" +"" +"" +"" +"" +"NG" +"T.S of spinal cord" +"controlled muscular activity, the dorsal fig-13: Peripheral nerves system" +"root did not." +"In 1822 they suggested that dorsal root carried messages of sensation" +"inwards while the ventral pathway carried outwards the instruction for" +"muscular contraction." +"LA" +"Which root according to you gets signals from afferent nerves?" +"The peripheral nervous system (PNS) is a vast system of the dorsal" +"and ventral root nerve cell heads and the network of spinal and cranial" +"TE" +"" +"nerves that are linked to the brain and the spinal cord on one end and muscles" +"on the other." +"What do you think the end of these nerves act at the muscular end?" +"Autonomous Nervous System" +"The PNS can either involuntarily control several functions of regions" +"T" +"" +"" +"" +"like our internal organs, blood vessels, smooth and cardiac muscles.So it" +"is called autonomous nervous system. It has voluntary control of muscles" +"ER" +"" +"" +"" +"" +"of some areas of skin and the skeletal muscle." +"We can take up an example to see how certain involuntary function" +"controlled by autonmous nervous system takes place in our body. A very" +"evident observation is the reduction and expansion of the pupil of our eye." +"SC" +"" +"" +"" +"" +"When we enter a dark room we cannot see anything immediately. Slowly" +"we are able to see the things around us in the room. This is because of" +"increase in diameter of pupil, which allows more light in. When we come" +"out of the dark room into broad day light the diameter of the pupil decreases" +"allowing less light to enter into the eyes. Both these functions occur under" +"the influence of the autonomous nervous system." +"Free distribution by T.S. Government 2019-20 103" +" Do you know ?" +"Research in the past two decades has brought out an interesting fact. Other" +"" +"" +"" +"" +"A" +"than central nervous system and peripheral nervous system, there is a system of" +"neurons present in our digestive tract that can function even independently of" +"" +"" +"" +"" +"AN" +"either CNS or PNS. It has been nick named as a second brain and the system is" +"called as enteric nervous system (ENS)." +"" +"" +"You know that medulla oblongata is the region that regulates heartbeat," +"breathing etc. the system that helps to bring about such activities of internal" +"" +"" +"" +"" +"NG" +"organs is called autonomous nervous system. Normally such involuntary" +"activities take place by the coordinated efforts of the medulla oblongata" +"and autonomous nervous system." +"Sympathetic Para sympathetic" +"" +"Dilates pupil Constricts pupil" +"LA" +"Inhibit salivation Stimulates salivation" +"" +"" +"Relaxes bronchi Constrict bronchi" +"TE" +"" +"Accelerates heart beat Inhibits heart beat" +"" +"Increase blood pressure Decrease blood pressure" +"" +"Inhibit pancreas activity Stimulates pancreas activity" +"T" +"" +"" +"Decreases secretion of Increases secretion of" +"digestive juices digestive juices" +"ER" +"" +"" +"" +"" +"Relaxes urinary bladder Contract urinary bladder" +"" +"Inhibit sex structures Stimulates sex structures" +"" +"" +"" +"fig-14: Autonomous nervous system" +"SC" +"" +"" +"" +"" +"Now let us see how the autonomous nervous system influences the" +"life activities. Observe the fig-14 and record your observations." +"To which organs of the body do the nerves go from the ganglions" +"near the vertebral column?" +"What are the organs that receives nerves starting from the brain?" +"Which are the organs whose activities are influenced by the" +"sympathetic system?" +"104 X Class Coordination - The liking system" +" Which are the organs whose activities are influenced by the" +"para sympathetic system?" +"What do you understand about the functions of para sympathetic" +"" +"" +"" +"" +"A" +"system?" +"What do you understand about the functions of sympathetic system?" +"" +"" +"" +"" +"AN" +"Ganglia near the vertebral column are connected to the spinal cord by" +"nerves. The sympathetic system is formed by the chain of ganglia on either" +"sides of the vertebral column and the associated nerves. The para" +"sympathetic system is formed by the nerves arising from the ganglia of" +"the brain and the posterior part of the spinal cord. These together constitute" +"the autonomous nervous system. It is the part of the peripheral nervous" +"" +"" +"" +"" +"NG" +"system consisting of twelve pairs of cranial nerves and thirty one pairs of" +"spinal nerves." +"Several functions in our body are controlled by nerves while many of" +"them and others are controlled by other ways as well. You might have heard" +"about people having diabetes and know that they have to take tablets or" +"insulin injections when the level of sugar in their blood rises.Let’s find" +"LA" +"out what insulin is and how we came to know about it. This would also give" +"us an idea of controls other than nerves in our body." +"Coordination without nerves" +"The Story of insulin" +"TE" +"" +"In 1868 Paul Langerhans, Professor of Pathology at the University of" +"Freiburg in Germany, working on the structure of the pancreas, noted certain" +"patches of cells quite different in appearance from the normal tissue cells" +"of the organ and richly supplied with blood vessels. They are known Islets" +"of Langerhans (Islets stands for islands), but their function remained" +"unknown. Many others interested in the function of pancreas and found" +"T" +"" +"" +"that its removal from the body of an experimental animal would lead to" +"the development of diseases similar to a well-known human ailment ‘sugar" +"ER" +"" +"" +"" +"" +"diabetes’. This is a condition in which the amount of free sugar in the" +"blood and in the urine is abnormally high. It’s a cause in man was unknown" +"but evidence pointed to the pancreas as a possible role." +"SC" +"" +"" +"" +"" +"fig-15: Pancreas fig-16: Paul Langerhans" +"Free distribution by T.S. Government 2019-20 105" +" The next stage was reached when it was found that tying up the" +"pancreatic duct that emerged from the duodenum( a part of the small" +"intestine) would cause the pancreas to degenerate but the Islets of" +"" +"" +"" +"" +"A" +"Langerhans would remain normal. Moreover, an animal so treated would" +"not develop diabetes. This was really a strong evidence that the level of" +"" +"" +"" +"" +"AN" +"blood sugar is linked with the islet cells. By 1912, workers were convinced" +"that the islets produced a secretion which directly liberated into the" +"blood. In Latin ‘insula’ means an island. The name insulin was coined" +"for the secretion, even though it had not been isolated." +"Ten years later in Toronto, Banting, Best, and Macleod finally" +"" +"" +"" +"" +"NG" +"succeeded in extracting insulin from degenerate animal pancrease whose" +"ducts to the intestine had been tied. When given by intravenous injection" +"to a dog with no pancreas, this substance kept it alive and healthy with a" +"low level of blood sugar. Insulin is now produced in large quantities for" +"the treatment of human sufferers from sugar diabetes, to whom it is" +"administered by injection into the skin." +"LA" +"Insulin thus is a chemical that acts as it reaches blood from the cells" +"that produce it." +"Other chemical co-ordinators" +"TE" +"" +"The evidence that events occurring in one part of the body could be" +"affected and indeed controlled by substances circulating in the blood was" +"now overwhelming. In 1905 the English physiologist Starling had coined" +"the term hormone (Greek, hormao – to impel) for such secretions. The" +"glands secreting hormones were termed ductless glands, since they have" +"no tube or duct to carry away their products, which pass straight into the" +"T" +"" +"" +"blood. In this way they differ from glands such as the liver and pancreas," +"whose secretions pass down ducts which are connected to other organs." +"ER" +"" +"" +"" +"" +"The human body contains many other ductless glands (endocrine" +"glands).Glands do not produce their hormones at a steady rate. The adrenal" +"gland, for example, normally has a low output." +"What will you do if a dog is after you? What" +"will be your first reaction? Have you ever observed" +"SC" +"" +"" +"" +"" +"any change in your body when you are afraid?" +"Nobody wants to fight with a dog. The first thing" +"we do is running away from the place." +"Try to note the body language of humans / animals" +"when they are fighting / scared." +"If we observe our body, when we are afraid, the" +"fig-17: Cock fight rate of heart beat increases; the breath rate will be" +"106 X Class Coordination - The liking system" +" faster; blood pressure increases; the hair on the body becomes erect and" +"we get goose bumps. The other things we might not observe are pupil" +"dilation, skin becomes more sensitive, and rarely the bladder and the rectum" +"" +"" +"" +"" +"A" +"may be emptied. We come to normal state only after we reach a safe spot." +"We have already studied about nerve co-ordination, where nerves carry" +"" +"" +"" +"" +"AN" +"stimuli from sense organs to central nervous system and orders to effectors" +"organs-the muscles. But, in the above situation the action of the nervous" +"system is limited. All the changes in the body are carried out under the" +"influence of a chemical called ‘Adrenalin’ hormone, released by Adrenal" +"gland which is an endocrine gland. The various actions of the body are" +"" +"" +"" +"" +"NG" +"controlled by hormones and co-ordinated by nervous system. So in this" +"type of conditions nervous system and endocrine system work together to" +"bring about control and co-ordination." +"Ask your teacher why Adrenalin hormone is also called fight or flight" +"hormone." +"The whole system of ductless glands is called the endocrine system." +"LA" +"Information about a few of the endocrine glands is given in the next page" +"accompanying table." +"Try to make a list of functions that you think are controlled both by" +"the nervous and the endocrine system." +"TE" +"" +"Feedback mechanism" +"Recall the fight or flight behavior of cat and dog. The amount of" +"adrenalin hormone increases in the blood sharply in a frightening situation," +"getting anger or excited." +"Have ever observed the duration of anger?" +"T" +"" +"" +"Why does anger come down?" +"What may happen if anger persists for a longer period?" +"ER" +"" +"" +"" +"" +"Anger is always short lived factor. You know that increased levels of" +"adrenalin are responsible for anxiety. When the levels of adrenalin in the" +"blood come down slowly we come to normal state. If the adrenalin levels" +"persist for a longer period of time, regular metabolic activities are" +"disturbed." +"SC" +"" +"" +"" +"" +"Increase in adrenalin levels leads to anger, decrease in adrenalin levels" +"leads to normal position." +"What will happen if it is continued for longer periods of time?" +"Similarly the sugar levels in the blood rise than normal level, they are" +"detected by the cells of pancreas, which respond by producing more insulin" +"into the blood. If the sugar levels come back to normal level secretion of" +"insulin is automatically reduced." +"Free distribution by T.S. Government 2019-20 107" +" Table-2: Endocrine glands" +"" +"" +"" +"" +"108" +"Name of the endocrine gland Location Hormone secreted Response of body to hormone" +"SC" +"Pituitary Floor of brain 1. Somatotropin Growth of bones" +"" +"" +"" +"" +"X Class" +"2. Thyrotropin Activity of thyroid gland" +"3. Gonadotropin Activity of ovary and testis" +"4. Adreno cortico trophic hormone Stimulates secretion from adrenal cortex" +"ER" +"5" +"5. Luteinising hormone In males - secretion of testosterone." +"In female - Ovulation, development of corpus luteum" +"and secretion of progesterone." +"T" +"6. Follicle stimulating hormone In male - spermatogenesis" +"In female - growth of graafian follicles, estrogen" +"secretion, milk production and secretion." +"7. Vasopressin Regulate absorption of water from the kidney tubules" +"TE" +"Thyroid Neck Thyroxine General growth rate and metabolic activity" +"Ovary Lower abdomen Estrogen Growth of the uterus and skeleton of the pelvis" +"Control of the 28 days menstrual cycle in females." +"Progesteron Development of uterus, implantation, development" +"LA" +"of mammary glands." +"Testes Scrotal sac Testosterone Growth of hair on face, muscular development," +"deepening of voice, normal sexual behavior and" +"development of male sex organs." +"NG" +"Adrenal Attached to Adrenalin Increase in heart-beat rate. Rise in blood sugar." +"kidneys Dilation of the coronary artery. Dilation of the pupil" +"of the eye. ." +"Pancreas Near duodenum 1. Insulin Decrease glucose percentage in blood" +"" +"" +"" +"" +"Coordination - The liking system" +"2. Glucagon Increase glucose percentage in blood" +"AN" +"A" +" So it is necessary that the hormones are secreted by the glands in our" +"body in precise quantities which are required for the normal functioning" +"of the body. This means that there should be some mechanism to regulate" +"" +"" +"" +"" +"A" +"the production and release of hormones in the body." +"The timing and amount of hormones released by endocrine glands is" +"" +"" +"" +"" +"AN" +"controlled by the feedback mechanism, which is inbuilt in our body. None" +"of the systems, whether nervous or chemical are totally exclusive of each" +"other." +"Control mechanisms in plants" +"" +"" +"" +"" +"NG" +"How do plants respond to stimuli?" +"So far we have studied how control mechanisms work in our body. Do" +"plants also have control systems? Let us find out by doing a small activity." +"Activity-4" +"LA" +"Touch the leaves of Mimosa pudica (athipathi, touch me not) plant and" +"observe the response of leaves. Are they folding? If so in which direction?" +"Try to give examples of situations where you may see plants responding" +"to a certain stimulus." +"TE" +"T" +"ER" +"" +"" +"" +"" +"fig-18: Mimosa pudica" +"" +"Do you know ?" +"Mimosa pudica leaves have pad like swellings at the base. They are called" +"SC" +"" +"" +"" +"" +"pulvini. Here cells contain lot of water and large intercellular spaces. Due to water" +"pressure pulvini hold the leaf erect. Touch me not plant shows nastic movement by" +"touch. This is called thigmonasty. When we touch the leaves, an electrical impulse" +"is generated. This impulse acts on plant hormone. Because of this hormone water in" +"the pulvini cells which are closer to the leaf vein migrate to other side of the cells.Then" +"pulvini loss its firmness hence leaves become fold. After 20 to 30 minutes water" +"comes back pulvini attains firmness and leaves become erect." +"Free distribution by T.S. Government 2019-20 109" +" You might have observed the tendrils of plants growing towards a" +"support. Can you imagine how is it happening? Would you think it is" +"responding to a stimulus?" +"" +"" +"" +"" +"A" +"Both plants and animals react to various stimuli around them. But the" +"method of responding to stimuli is not similar in plants and animals. Higher" +"" +"" +"" +"" +"AN" +"animals respond to stimuli because they have a nervous system and an" +"endocrine system. Plants do not have a well-defined nervous or endocrine" +"system. They do have some mechanism of control by means of some" +"chemicals or hormones." +"Plants can sense the presence of stimuli like light, heat, water, touch," +"" +"" +"" +"" +"NG" +"pressure, chemicals, gravity etc. The hormones present in the plants called" +"phytohormones (phyto means plant) control responses towards the stimuli" +"mentioned above. Phytohormones coordinate the activities of the plant" +"usually by controlling one or the other aspect of the growth of the plant." +"So plant hormones are also called growth substances. Some major plant" +"LA" +"hormones and their action are given in the following table." +"Table-3: Major plant hormones and their action" +"Hormones Uses" +"Auxins cell elongation and differentiation of shoots and roots" +"TE" +"" +"Cytokinins promote cell division, promotion of sprouting of lateral buds, delaying" +"the ageing in leaves, opening of stomata." +"Gibberellins germination of seeds and sprouting of buds; elongation of stems;" +"stimulation of flowering; development of seedless fruits, breaking the" +"dormancy in seeds and buds." +"T" +"" +"" +"" +"Abscisic acid closing of stomata; seed dormancy, promoting aging of leaves." +"Ethylene ripening of fruit" +"ER" +"" +"" +"" +"" +"Discuss with your teacher about seed dormancy." +"Activity-5" +"Take a glass jar and fill with soil. Sow a bean seed near the wall of" +"SC" +"" +"" +"" +"" +"the jar. This helps you to observe how root and shoot are growing. After" +"4 - 5 days you will notice seed germination. Keep the jar under the sun." +"Observe how root and shoot grows. Then tilt the glass jar and keep the" +"plant horizontally. Observe the direction of root and shoot growth for" +"more than a week." +"Does the shoot take a horizontal tilt after a week?" +"" +"" +"110 X Class Coordination - The liking system" +" Which side of the shoot may have grown more and which" +"side less to bring about this effect?" +"Observe the plant growing towards light think how auxins" +"" +"" +"" +"" +"A" +"act on bending of stem to show a response to the sunlight." +"More auxin collects on the shaded side of the stem. So cells" +"" +"" +"" +"" +"AN" +"on that side grow faster. On opposite side cells grow slow to" +"make the stem bend." +"Collect bending and straight portions of tender stem. Take" +"transverse sections of both stems, observe them under" +"microscope. fig-19: Bending" +"" +"" +"" +"" +"NG" +"towards sun" +"Do you find any difference in the shape of epidermal cells?" +"Charles Darwin and his son Francis Darwin performed" +"Light" +"some experiments on phototropism. They covered the Shaded side" +"terminal portion of the tip of stem(coleoptile) with a" +"cylinder of metal foil. Exposed the plant to light coming" +"LA" +"from the side. The characteristic bending of the seedling" +"did not occur. When, light was permitted to penetrate the" +"cylinder bending occurred normally. They stated that when Lighted side" +"seedlings are freely exposed to a lateral light some" +"‘influence’ is transmitted from upper to the lower part" +"TE" +"" +"causing the material to bend." +"In 1926, the Dutch plant physiologist F.W. Went" +"fig-20: Elongation of cells" +"succeeded in separating this ‘influence’ from the plant" +"that produced it. Went cut off coleoptile tips from oat seedlings. He placed" +"the tips on a slice of agar and left them for about an hour. He then cut the" +"agar into small blocks and placed a block on one side each stump of the" +"decapitated plants. They were kept in the dark during the entire experiment." +"T" +"" +"" +"" +"Within one hour he observed a distinct bending away from the side on" +"which the agar block was placed." +"ER" +"" +"" +"" +"" +"Agar block that had not been in contact with coleoptile" +"tip produced either no bending or only a slight bending" +"toward the side on which the block had been placed." +"Went interpreted these experiments as showing that fig-21: Went experiment" +"the coleoptile tip exerted its effect by means of chemical stimulus rather" +"SC" +"" +"" +"" +"" +"than a physical stimulus such as an electrical impulse. This chemical" +"stimulus came to be known as auxin. In this way the first plant hormone" +"auxin (greek word auxin means to increase) was discovered by Went." +"Tropic and nastic movements in plants" +"The above experiments show that movement of individual parts of plants" +"is possible when they are subjected to external stimuli. This type of" +"Free distribution by T.S. Government 2019-20 111" +" response is called tropism or tropic movement. Sometimes the direction" +"of stimuli determines direction of movement, sometimes the direction of" +"movement may not be determined by direction of stimuli. This type of" +"" +"" +"" +"" +"A" +"response is called nastic movement." +"Let us observe the growth of a creeper plant near window. The shoots" +"" +"" +"" +"" +"AN" +"of creeper bend towards sunlight. Such type of response of a plant to light" +"is called photo tropism (photo means light, tropism means movement)." +"We know that roots always grow downwards. This means that plant" +"respond positively for gravitational force. This is called geotropism." +"If we observe plant which grow near a rock or wall side. You notice" +"" +"" +"" +"" +"NG" +"that all roots are growing in one direction, away from the rock or wall" +"where water is available in the soil. This type of response to water is called" +"hydrotropism." +"A very interesting thing in plants is movement of tendrils. All plants" +"show positive response to phototropism. But in creepers like cucumber," +"LA" +"bitter gourd, the stem is weak and thin. Hence plant cannot grow erect." +"Tendrils play a vital role to make the plant erect. Tendrils are thin thread" +"like growths on the leaves or stems of climbing plant. They grow towards" +"support and wind around them. This type of response to make contact or" +"TE" +"" +"touch is called thigmo tropism." +"If you taste the carpel of a flower it is sweet. Let us" +"recall butterflies fluttering on flowers for this nectar." +"Ripen stigma secretes sugary substance. This chemical" +"substance stimulates the pollen grain which falls on the" +"T" +"" +"" +"stigma. Pollen grain responds to this stimulus as pollen" +"fig-22: Tendrils tubes grow to reach the ovule for fertilization. This type" +"ER" +"" +"" +"" +"" +"of response to chemicals is called chemo tropism. Unequal distribution" +"of auxins affects the root and the stem growth. High concentration of auxin" +"stimulates stem growth and inhibit root growth." +"" +"" +"Key words" +"SC" +"" +"" +"" +"" +"Response, stimuli, neuron, schwann cell, axon, synapse, afferent or sensory nerves," +"efferent or motor nerves, association nerves, central nervous system, brain, spinal cord," +"cerebrospinal fluid, peripheral nervous system, insulin, endocrine glands, hormones," +"feedback mechanism, plant hormones, tropic movements, nastic movements." +"" +"" +"" +"112 X Class Coordination - The liking system" +" What we have learnt" +"" +"" +"" +"" +"A" +"Nervous system and endocrine system are the two systems that control and coordinate various" +"functions in the body." +"The responses of the nervous system can be classified as reflex, voluntary and involuntary actions." +"" +"" +"" +"" +"AN" +"The human nervous system is studied under two divisions: The central nervous system and the" +"peripheral nervous system." +"The central nervous system consists of brain and the spinal cord while the peripheral nervous" +"system is further divided into somatic nervous system and autonomous nervous system." +"The autonomus nervous system has two parts – sympathetic and parasympathetic, which cause" +"" +"" +"" +"" +"NG" +"physical reactions opposite to each other." +"Nerve cell is the structural and functional unit of nervous system." +"Synapse is a gap across where signals are transmitted from one neuron to the other." +"Hormones produced in one part of the body would move to another part to achieve the desired" +"effect." +"A feedback mechanism regulates the action of the hormones." +"LA" +"Directional movements in plants in response to specific stimuli like light, chemicals etc. are called" +"tropic movements." +"Plant hormones are usually growth promoters or inhibitors. Some growth promoters are auxins" +"and gibberellins, while growth inhibitors are abscisic acid and ethylene." +"" +"Improve your learning" +"TE" +"" +"1. Fill in the missing sections in the following flow chart.(AS1)" +"Step on a sharp Spinal cord analyse" +"edged object information and" +"send commands" +"T" +"" +"" +"" +"2. Do you think body’s team work maintains functioning of our body? Justify your answer with an" +"example.(AS1)" +"ER" +"" +"" +"" +"" +"3. Give an example of coordination in your body where both hormonal and nervous controls function" +"together.(AS1)" +"4. Consider that you are passing by a garbage disposal area and you immediately cover your nose." +"Arrange the events below in a logical order by marking them from 1 to 5 to trace the events that" +"happen in the nervous system from detection of foul smell (stimulus generation) to covering your" +"nose (response).(AS1)" +"SC" +"" +"" +"" +"" +"(i) At the end of the axon, electrical impulse releases chemicals" +"(ii) Stimulus received by the dendrites of a neuron sets off chemical reaction that creates an" +"electrical impulse" +"(iii) Electrical impulse transmitted through cell body and axon" +"(iv) The chemicals cross the synapse and reach the next neuron. Similarly, the electrical impulse" +"crosses several neurons" +"(v) Finally, the impulse is delivered from neuron to the gland that helps in recognition of the foul" +"smell and muscle cells that help in covering the nose" +"Free distribution by T.S. Government 2019-20 113" +" 5. What is a synapse? How is it useful in transfer of information?(AS1)" +"6. Distinguish between(AS1)" +"a) Stimulus and Response b) Afferent and Efferent nerves" +"" +"" +"" +"" +"A" +"c) Central nervous system and peripheral nervous system d) Receptor and effector" +"7. How does Phototropism occur in plants?(AS1)" +"8. Give an example and explain how plants may immediately respond to a stimulus.(AS1)" +"" +"" +"" +"" +"AN" +"9. Suggest an experiment to show how roots grow away from light in most plants.(AS1)" +"10. Give an example to show how hormones can influence visible changes in your body.(AS1)" +"11. How does a neuron differ from an ordinary cell in structure? Write notes.(AS1)" +"12. Is the structure of neuron suitable for transmission of impuleses? Analyse.(AS1)" +"13. Man is the most intelligent animal. What could be the fact that helped us to reach such a" +"" +"" +"" +"" +"NG" +"conclusion?(AS1)" +"14. The axon of nerve cell in hand is shorter than the axon of nerve cell in leg. Do you support this" +"statement? Why?(AS1)" +"15. Organs respond to the external stimulus by a fraction of second. How do you feel about such" +"controlling mechanism of human body?(AS1)" +"16. State whether the following actions are voluntary action, reflex action or conditioned reflex.(AS1)" +"i) Blinking" +"LA" +"ii) Cleaning the table iii) Playing on the key board" +"iv) Salivating when food is put in the mouth. v) We close our ears when we hear un bearble sound" +"17. What will happen to the potted plant kept near window in the room?(AS2)" +"18. What happens if all functions of the human body is controlled only by brain?(AS2)" +"19. If you visit a doctor what doubts you would like to clarify about pancreas?(AS2)" +"TE" +"" +"20. Take a small potted plant. Cover base portion of the plant tightly and hang the part upside down." +"Observe the plant for a week. Based on your observation how can you support phototropism.(AS3)" +"21. Take a cock feather touch smoothly at different parts of your body. Findout which portion of the" +"body has high sensation. Is this similar during sleeping? Prepare a report on it. (AS3)" +"22. What procedure do you follow to understand the effect of plant growth hormones (in agar medium)" +"in the terminal portion of the tip of stem (coleoptile)?(AS3)" +"T" +"" +"" +"" +"23. Collect information on the actions controlled by spinal cord by using reference books from your" +"school library.(AS4)" +"ER" +"" +"" +"" +"" +"24. Read the following sentences and compare with endocrine glands.(AS4)" +"(a) Pheromones are chemical substances secreted by organisms. (b) These act as chemical signals" +"secreted by exocrine glands. (c) Pheromones are used as signals by the members of same species." +"(d) Honey bee secretes pheromones that attract other bees to the location of food." +"25. Collect the information about cranial nerves. Spinal nerves from internet or from your school" +"library.(AS4)" +"SC" +"" +"" +"" +"" +"26. Draw a picture representing connection between dendrite-dendrite, axon-dendrite. Why do they" +"connect like that?(AS5)" +"27. Draw a neatly labelled diagram of Brain and write few points how it is protected.(AS5)" +"28. You are walking in the traffic suddenlyyou heard a loud sound. How coordination takes place in" +"this situation among respected organs? Draw a block diagram to explain this situation.(AS5)" +"29. Make a model of neuron using suitable materials.(AS5)" +"" +"" +"114 X Class Coordination - The liking system" +" 30. Observe different actions performed by your classmate for a period of 45 minutes. Out of" +"those actions which are controlled by voluntary and involuntary pathways.(AS5)" +"31. Its very interesting to watch a creeper entwining its tendril to the support. How do you" +"" +"" +"" +"" +"A" +"appreciate it? (AS6)" +"32. Hormones are released at a speicific place, specific time for a specific function. Prepare a" +"cartoon on hormones with a nice caption.(AS7)" +"" +"" +"" +"" +"AN" +"Fill in the blanks" +"" +"1. The largest region of the brain is ___________" +"" +"" +"" +"" +"NG" +"2. A point of contact between two neurons is ____________" +"3. _____ phytohormon is resposible for cell elongation and differentiation of shoot tips and root tips." +"4. Thryoxin is resposible for ______________" +"5. Gibberellins and auxins promote growth in plants while abscisic acid arrests the same. Some situations" +"are discussed here, State which hormones would be needed and why?" +"A) To grow a large Dahlia plant a gardener should use nutirients along with ________ hormone." +"LA" +"B) To grow long branches in dwarf plants, one would use ___________ hormone." +"C) Seeds are to be stored for a long time _____________ hormone can help." +"D) When the apex / stem tip is cut off, to ensure growth of several lateral buds ____________" +"hormone has to be used." +"TE" +"" +"Choose the correct answer" +"" +"6. A person has loss of control on emotions, which part of brain stops it’s function. ( )" +"A. cerebrum B. diencephalon C. mid brain D. cerebellum" +"T" +"" +"" +"" +"7. Leaf movement in mimosa helps to ( )" +"A. reduce photosysthesis B. protect from grazers" +"ER" +"" +"" +"" +"" +"C. releasing phytohormones D. regulate it’s growth" +"8. Diabetes is related to this gland. ( )" +"A. Thyroid B. pancreas C. adrenal D. pituitary" +"SC" +"" +"" +"" +"" +"Free distribution by T.S. Government 2019-20 115" +" A" +"Chapter" +"" +"" +"" +"" +"AN" +"6" +"" +"" +"NG" +"Reproduction - The generating system" +"LA" +"1. In plants and animals reproduction is a necessary life process for" +"continuation of life by producing of offsprings ." +"Do you think reproduction occurs only for continuation of life?" +"How does an organism grow? How does repair of worn out parts take" +"place? Is there any other form of reproduction involved in the process?" +"TE" +"" +"2. Organisms are capable of giving rise to offsprings by the process of" +"reproduction. Some organisms may reproduce differently in different" +"situations. For example, under favourable conditions paramoecium give" +"rise to more of its kind from a single parent by simply splitting into two." +"This happens rapidly and several of them are formed. During unfavourable" +"T" +"" +"" +"conditions two paramoecia come in contact and exchange certain materials" +"of their bodies and produce forms that are more tolerant (conjugation)." +"ER" +"" +"" +"" +"" +"The time required to reproduce also varies from organism to organism." +"Even within the organism there could be certain environmental conditions" +"that would make faster the process of reproduction." +"Let us do an activity to find out how fast an organism might be reproducing" +"SC" +"" +"" +"" +"" +"Acitivity-1" +"Formation of bacterial colony in milk" +"We are aware that, Lactobacillus bacteria is responsible for formation" +"of curd. Take a tea spoon ful of curd and mix it thoroughly with around 30" +"tea spoon ful of (half of the glass) luke warm milk in a bowl. Take another" +"tea spoon ful of curd and mix it with 30 tea spoon ful of cold milk in" +"" +"116 X Class Reproduction - The generating system" +" another bowl. Cover both the bowls with lids and note down the initial" +"time. Keep on observing the two bowls every hour to see whether curd" +"has been formed or not. Curdling indicates that, there is an increase in" +"" +"" +"" +"" +"A" +"number of bacteria." +"Note the time taken for formation of curd in both the bowls." +"" +"" +"" +"" +"AN" +"Did it take the same time to form curd in both the bowls?" +"What was the time taken to form 30 times the size of the bacterial" +"colony? What did it indicate?" +"Think, how fast they are growing. During rainy season you may have" +"wondered to see how swarms of insects suddenly appear. Most insects" +"have life cycles spanning a few days to a few months. You will find great" +"" +"" +"" +"" +"NG" +"variations in the periods of reproduction viz. yeasts, bacteria, rat, cow," +"elephant and man." +"Asexual mode of reproduction" +"Let us study the different modes of reproduction involving a single" +"parent, without involving gametes. This type of reproduction is known as" +"LA" +"asexual reproduction." +"Organisms can reproduce asexually in many ways. Some of them are" +"discussed below :" +"Fission" +"TE" +"" +"Single celled organisms, such as Paramoecium and" +"bacteria, reproduce by splitting into two or more offsprings." +"This usually occurs in a symmetrical manner. They split into" +"two by transvers binary fission. When more cells are formed fig-1:" +"it is called multiple fission. This is often the only mode of Fission in paramoecium" +"reproduction in these organisms." +"T" +"" +"" +"" +"How do you think bacteria were dividing to form curd?" +"Budding" +"ER" +"" +"" +"" +"" +"A growth on the body as a bud that grows to form nearly" +"identical copy of parent. When the bud totally grows then it" +"separates from the parent and survives independently. Eg:" +"Yeast." +"fig-2: Budding in yeast" +"Fragmentation" +"SC" +"" +"" +"" +"" +"Some of the organisms can grow from a single piece of" +"the parent organism. This can be from any part of the body." +"Fragmentation occurs only in the simplest, such as some" +"flatworms, molds, lichens, Spirogyra etc. These may also" +"reproduce sexually. Fragmentation is a common mode of" +"reproduction in algae, fungi and many land plants. fig-3: Fragmentation in" +"spirogyra" +"Free distribution by T.S. Government 2019-20 117" +" Parthenogenesis" +"In general sexual reproduction takes place by the fusion of haploid" +"gametes forming a diploid zygote. Do you know, in certain cases the" +"" +"" +"" +"" +"A" +"organisms develop directly from unfertilized gametes." +"Let us see, how this process occurs?" +"" +"" +"" +"" +"AN" +"This process occurs commonly in lower organisms such" +"as algae and fungi eg: Spirogyra. The process of development" +"of young ones from unfertilized gametes is called" +"parthenogenesis. (In greek partheno means virgin; genesis" +"means production)" +"What about animals?" +"" +"" +"" +"" +"NG" +"This strange kind of reproduction occurs in animals like" +"fig-4: Seedless fruit some species of ants, bees and wasps the fertilized ovum" +"(zygote) develops into female and unfertilized ovum develops into male." +"In this process the sperms develop by mitotic division in male where as" +"ova develop by meiotic division in female." +"Parthenocarpy: Now a days we are able to develop seedless fruits like" +"LA" +"watermelon, grapes etc. Naturally in some plants like banana ovary directly" +"develops into fruit without the process of fertilization this phenomenon" +"is called as “Parthenocarpy”." +"“Parthenocarpy”. These fruits are seedless. In many crops" +"like pomegranate, papaya, tomatoes etc, parthenocarpy is" +"induced. Recall the phyto hormone that induces parthenocarpy" +"parthenocarpy." +"TE" +"" +"Did you realise that pathenogenesis is asexual" +"reproduction." +"Discuss with your teacher about plants and animals that" +"show parthenocarpy, parthenogenesis. Prepare a bulletin." +"Regeneration" +"Many organisms have the ability to give rise to new" +"individual organisms from their body parts. That is, if the" +"T" +"" +"" +"fig-5:" +"individual is somehow cut or broken up into many pieces," +"Regeneration in" +"these pieces grow into separate individuals. This is similar to" +"planaria" +"ER" +"" +"" +"" +"" +"fragmentation." +"Is Regeneration can also be known as a type of fragmentation? Do" +"you agree? Why? Why not?" +"Which type of fission would produce larger colonies in less period" +"of time. Why?" +"Which mode of asexual reproduction provides maximum scope of" +"SC" +"" +"" +"" +"" +"choice of desirable characters?" +"Vegetative propagation" +"In higher plants vegetative propagation. may be natural or artificial." +"Natural propagation" +"Leaves: In Bryophyllum small plants grow at the edge of leaves." +"Stems: Aerial weak stems like runners and stolons, when they touch the" +"fig-6: ground, give off adventitious roots. When the connection with the parent" +"Bryophyllum plant is broken, the stem portion with the adventitious roots develops into" +"" +"118 X Class Reproduction - The generating system" +" an independent plant. Some examples for propagation by stem are from" +"stolons, bulbs, corms, tuber, etc." +"Stolons - Jasmin, strawberry, Bulbs - Onion (Allium Cepa), Corms -" +"" +"" +"" +"" +"A" +"Colacasia, Rhizome - ginger Tuber - potato, Root - Roots of Murraya," +"Guava, Millingtonia (radical buds) etc., grow as new plants." +"" +"" +"" +"" +"AN" +"NG" +"Tuber Stolon Root buds in" +"Bulb Corms" +"fig-7 Millingtonia" +"Artificial propagation" +"Cutting:" +"Some plants can grow individually when a" +"piece of the parent plant having bud is cut off" +"LA" +"from the existing plant. The lower part of this" +"cutting is buried in moist soil. After few days," +"the cut parts having buds grows as an individual" +"plant after developing roots. Eg: Rose, Hibiscus fig-8: Cutting" +"TE" +"" +"Layering:" +"A branch of the plant with at least one node is bent" +"towards the ground and a part of it is covered with moist weak branch" +"soil leaving the tip of the branch exposed above the" +"ground. After a few days, new roots develop from the" +"T" +"" +"" +"part of the branch buried in the soil. The buried branch is" +"then cut off from the parent plant. The part which has" +"ER" +"" +"" +"" +"" +"developed roots grows to become a new plant. Eg:" +"fig-9: Layering" +"Nerium, Jasmine." +"Grafting:" +"Two plants are joined together in such a way that two scion" +"stems join and grow as a single plant. One which is" +"SC" +"" +"" +"" +"" +"attached to soil is called stock and the cut stem of another" +"plant without roots is called scion. Both stock and scion" +"are tied with the help of a twine thread and covered by a stock" +"cover. Grafting is used to obtain a plant with" +"polythene cover" +"desirable characters. This techqnique is very useful in" +"propagating improved varieties of plants with various" +"flowers and fruits (eg: Mango, citrus, apple, rose). fig-10: Grafting" +"" +"Free distribution by T.S. Government 2019-20 119" +" By grafting a very young scion (shoot part of a plant) can be made to" +"flowers and produce fruits the earlist." +"If you have two varieties of fruit yielding trees in your garden. One" +"" +"" +"" +"" +"A" +"tree has the character of giving big sized fruits but less in number. The" +"taste of the fruit is pretty good. The other one produce more number of" +"" +"" +"" +"" +"AN" +"fruits but they are neither big in size nor tasty." +"What are the characters would you like to select?" +"What mode of propagation would help you to produce the plants" +"with desirable characters?" +"Whether they reproduce by budding or fission or fragmentation?" +"And organisms formed the exact are copies of their parents. Is it" +"" +"" +"" +"" +"NG" +"true? Why?" +"Cutting, layering and grafting are the traditional methods of" +"artificial propagation in plants. Examples of plants produced in this" +"manner are Banana, Pineapple, Orange, Grape, Rose, etc." +"Do you know?" +"LA" +"For commercial purposes; they are being replaced" +"by the modern technology of artificial propagation of" +"plants involving tissue culture. In tissue culture, few plant" +"cells or plant tissue are placed in a growth medium with" +"TE" +"" +"plant hormones in it and it grows into new" +"plants.Thousands of plants can be grown in very short" +"interval of time." +"Collect information from your school library or internet about" +"advantages and disadvantages of artificial vegetative propagation and discuss" +"T" +"" +"" +"it in your class room with your teacher and classmates." +"Spore formation:" +"ER" +"" +"" +"" +"" +"Generally we may notice whitish thread like structures and blackish" +"powdery like substance on rotten fruits, bread slices and other food" +"materials. When you touch it, the blackish powder sticks on your fingers." +"These are the reproductive spores produced by fungi. Ex: Rhizopus. You" +"have already learnt about this in the chapter ‘The story of micro organisms’" +"in class VIII." +"SC" +"" +"" +"" +"" +"Rhizopus produces hundreds of microscopic reproductive units called" +"spores. When the spore case (also called sporangium) bursts, the spores" +"spread into air. These air-borne spores when fall on food or soil, under" +"favourable conditions like damp and warm conditions, they germinate and" +"produce new individuals. Fungi like Rhizopus, Mucor a few Bacteria and" +"some non-flowering plants such as ferns and mosses reproduce by this" +"method of spore formation." +"120 X Class Reproduction - The generating system" +" Lab Activity" +"" +"" +"" +"" +"A" +"To examine Rhizopus or common mold under the microscope, it is" +"best to grow on your own in a controlled environment. Use a soft bread" +"that is preservative free or a roti, fruits or vegetables such as potatoes or" +"" +"" +"" +"" +"AN" +"oranges. A good sample of mold may require 4-10 days to form spores so" +"be sure to plan ahead for this project. (Please note: this should not be" +"done by those with allergies to mold or with severe asthma.) Sporangium" +"Spore" +"Hyphae" +"" +"" +"" +"" +"NG" +"Hyphae" +"" +"" +"Bread" +"" +"Rhizopus growing on bread" +"LA Rhizopus mycelium seen under Rhizopus sporongium" +"microscope" +"fig-11" +"Leave the bread in the open air for about an hour, so it is exposed to" +"contaminants in the air. Place the bread in a plastic bag, sprinkle water" +"TE" +"" +"over it to have dampness, then seal the bag, leaving some air inside. Place" +"the bag in a dark, warm place. A kitchen cup board close to the stove may" +"be one option. Or you could place it next to a window, with a bowl or lid" +"covering it from the light. Mold will grow best in a moist environment." +"Mold would start growing in 2-3 days, but will take a week or more to" +"form spores depending upon the weather conditions." +"T" +"" +"" +"" +"Check the piece of bread every few days, and add some water if it is" +"drying. Avoid opening the plastic bag as much as you can. If you touch the" +"ER" +"" +"" +"" +"" +"bread, be sure to thoroughly wash your hands afterwards. When sufficient" +"mold has formed, you can prepare a slide and examine it under the" +"microscope. You would find whitish thread like growth with masses of" +"black, grey and green fine dotted structures (See fig-11). The black dotted" +"structure is that of bread mold. Take a part of the bread or roti to school in" +"a matchbox and ask your teacher to help you to make a slide and observe" +"SC" +"" +"" +"" +"" +"under the microscope." +"Aim: To prepare temporary slide of Rhizopus." +"Material required: Mold sample, plain glass slide, coverslip, water," +"disposable gloves." +"Procedure:" +"1. Place a drop of water in the centre of the slide." +"" +"Free distribution by T.S. Government 2019-20 121" +" 2. Using a toothpick, scrap very little of the mold and place it on the" +"drop of water." +"3. Take the cover slip and set it at an angle to the slide so that one edge of" +"" +"" +"" +"" +"A" +"it touches the water drop, then carefully lower it over the drop so that" +"the cover slip covers the specimen without trapping air bubbles" +"" +"" +"" +"" +"AN" +"underneath." +"4. Use the corner of a tissue paper or blotting paper to blot up any excess" +"water at the edges of the cover slip." +"5. View the slide with a compound microscope first observe under low" +"power." +"" +"" +"" +"" +"NG" +"The common bread mold consists of fine thread like projections called" +"hyphae and thin knob like structures called Sporangia (sporangium in" +"singular). Each sporangium contains hundreds of minute spores. When" +"the sporangium bursts, the tiny spores are dispersed in air." +"Try to give some more examples of organisms which reproduce through" +"spore formation." +"LA" +"Sporophyll:" +"Ferns also produce spores. Collect a fern leaf which is called" +"sporophyll. Observe the leaf carefully." +"carefully On the lower surface of the leaf" +"TE" +"" +"you find clusters of dot like structures called sorus. These" +"contain sporangia. Gently rupture the sorus with a needle" +"and observe spores by using magnifying lens." +"Do you find any similarities between rhizopus and" +"fern spores and sporongia?" +"What about mushrooms, how do they grow? Discuss" +"T" +"" +"" +"" +"fig-12: Fern sporophyll in your class." +"Sexual reproduction" +"ER" +"" +"" +"" +"" +"As you have studied earlier, sexual reproduction is a method of" +"reproduction where fusion of gametes takes place, by a process called" +"fertilisation. Fertilisation may occur either outside the body of the female" +"organism (external fertilisation) or inside the female’s body (internal" +"fertilisation). As a matter of fact, the eggs of land animals are fertilised" +"SC" +"" +"" +"" +"" +"inside the body of the female organism. The fertilized egg (the zygote)" +"start dividing and grow into the embryo." +"External fertilisation is a common in aquatic animals like most of the" +"fishes and amphibians. The female lays a vast number of eggs in water and" +"male animal release some millions of sperms on them. As the chance of" +"fertilisation is controlled by nature which occurs externally, hence it is" +"inevitable to produce a vast number of eggs and sperms." +"122 X Class Reproduction - The generating system" +" Reproduction in placental mammals - Human beings" +"While talking about placental mammals especially human beings" +"special reproductive organs have been developed in males and females to" +"" +"" +"" +"" +"A" +"carry out reproduction. Let us study them in detail." +"Male reproductive system" +"" +"" +"" +"" +"AN" +"Ureters" +"Observe the fig-13(a) of male reproductive Urinary bladder" +"system and findout the parts. (1) a pair of testes, Vasdeferens" +"(2) vasa efferentia, (3) a pair of epididymis, (4) seminal ducts" +"a pair of vasa deferentia, (5) a pair of seminal seminal vesicle" +"vesicles, (6) ejaculatory duct, (7) prostate gland, prostate gland" +"" +"" +"" +"" +"NG" +"(8) a pair of cowper’s gland, (9) urethra." +"Testes : The testes are located outside the" +"abdominal cavity within a pouch called scrotum. penis" +"In each testis highly coiled seminiferous tubules urethra" +"epididymis" +"are present. The sperms are produced in these" +"tubules by meiosis in very large numbers" +"LA testis" +"(hundreds of millions). Male sex hormone scrotum" +"testosterone is also produced in testis. fig-13(a): Male reproductive system" +"Think why testis are located outside the" +"abdominal cavity?" +"TE" +"" +"The scrotum helps in maintaining low temperature of the testis" +"(2-2.5 C lower than the body temperature) necessary for sperm formation." +"o" +"" +"Vasa efferentia : The seminiferous tubules open into vasa efferentia." +"They carry sperms into the epididymis." +"Epididymis : One in each side, the vasa efferentia open into epididymis" +"which is a highly coiled tube located along the posterior side of testis." +"T" +"" +"" +"" +"Sperms are stored in them." +"Vasa deferentia : From each epididymis arises vas deferens which ascends" +"ER" +"" +"" +"" +"" +"into the abdominal cavity looping around the ureter." +"Seminal vesicles : They open into the vas deferens. They produce seminal" +"fluid. It is the source of energy for sperms when they are outside the body." +"Prostrate gland: The main function of the prostrate gland is to secrete" +"prostrate fluid which is one of the component of semen it activity and" +"SC" +"" +"" +"" +"" +"supplies nutrients to the sperm." +"Cowper’s gland : Secretions of these glands help to neutralise the acidity" +"in the walls of urethra and the free flow of the sperm cells" +"Ejaculatory duct : A duct from seminal vesicles joins the vas deferens and" +"continuous as ejaculatory duct. Two ejaculatory duct join at the centre urethra." +"Urethra : In male it transports not only urine but also sperms. It is also" +"called as urino-genital duct." +"Free distribution by T.S. Government 2019-20 123" +" The passage of spermetozoa :" +"Seminiferous tubules - vasa efferentia - epididymis - vasa deferentia -" +"ejaculatory duct - urethra." +"" +"" +"" +"" +"A" +"Acrosome The sperm :" +"Head Observe the figure 13(b). The sperm has a head which bears" +"" +"" +"" +"" +"AN" +"Nucleus acrosome. It helps the sperm in penetrating into ovum in the middle" +"Neck" +"Mitochondria of the head male nucleus is present. It fuses with the female nucleus." +"Middle piece Head and middle piece are attached by neck. Mitochondria of middle" +"piece produce energy for the movement of the sperm. The tail propels" +"Tail the sperm. The fluids secreted from seminal vesicles, prostate gland" +"" +"" +"" +"" +"NG" +"and cowper’s gland collectively called seminal plasma. The seminal" +"plasma along with sperm is called semen." +"The sending out of semen from male’s body is called ejaculation." +"From normal fertility 60% of sperm should have normal shape and" +"size. And 40% of them must have vigorous motility." +"LA" +"Men produce sperm, from the age of about 13 or 14 years, and" +"fig-13(b): can go on doing so most of their lives, although their power to do so" +"Sperm cell decreases as they grow older." +"Female reproductive system" +"TE" +"" +"Observe the fig-14. The important parts of the female reproductive" +"system are (1) a pair of ovaries, (2) a pair of fallopian tubes, (3) uterus," +"(4) vagina. (The functional mammary glands also integrate with female" +"reproductive system)" +"Ovaries : The ovaries are located in the abdominal cavity. The ova develop" +"T" +"" +"" +"in tiny cellular structures called follicles" +"follicles, which at first look like cellular" +"bubbles in the ovary. They are called graafian follicles. As a follicle grows," +"ER" +"" +"" +"" +"" +"it develops a cavity filled with fluid. Each follicle contains a single ovum" +"which is formed after the process of cell division (meiosis). When an" +"ovum is mature, the follicle ruptures at the surface of the ovary and the" +"fallopian tube tiny ovum is flushed out. This release of" +"the egg or ovum is called ovulation." +"Fallopian tubes : Generally the ovum" +"SC" +"" +"" +"" +"" +"funnel enters the widened funnel of an oviduct" +"(fallopian tube), a tube that extends from" +"ovary the neighbourhood of an ovary to the" +"uterus" +"muscular, thick-walled uterus." +"cervix" +"Fertilization occurs as the ovum passes" +"vagina" +"through the fallopian tubes thus begins a" +"fig-14: Female reproductive system new life. The second phase of meiosis" +"124 X Class Reproduction - The generating system" +" of ovum is carried out after the entry of sperm before fusing of both nuclei." +"After fusion of both nuclei the ovum transforms into zygote." +"The zygote under goes mitotic division while travelling down in the" +"" +"" +"" +"" +"A" +"fallopian tubes. By the time it reaches the uterus and transforms into a" +"solid ball of cells." +"" +"" +"" +"" +"AN" +"Uterus : It is inverted pear shaped structure. The inner layer of uterus is" +"called endometrium. The thickness of these layers increases gradually soon" +"after menstruation. It will be ready to receive the embryo. If there is no" +"fertilization the endometrium disintegrates and flows out as menstrual" +"fluid. If there is fertilization the thickness of endometrium continues and" +"" +"" +"" +"" +"NG" +"ready to receive the embryo. It provides nourishment and" +"chorion" +"disposes of wastes of the developing embryo." +"The fertilized ovum undergoes mitotic divisions, while umbilicalcord" +"it moves down the oviduct and finally attaches to the soft" +"amnion" +"tissues of the uterus. Once attached, the embryo sinks into" +"placenta" +"LA" +"the soft inner uterine wall. This is called as implantation of" +"embryo. Then certain cells of the embryo develop into fig-15: Human embryo" +"membranous structures that help to nourish, protect, and support the" +"fig-16:" +"developing embryo. They are chorion, amnion, allantois, yolk sac." +"Developmental" +"TE" +"" +"Chorion: During the development of the embryo, tiny finger like stages of human" +"projections grow from the surface of the outer membrane called chorion embryo" +"into the soft tissues of the uterus. Gradually, small pools of rapidly moving" +"1" +"blood around these finger like projections in the uterine wall. These tissues" +"of the chorion and the adjacent part of the uterine tissue make up the placenta." +"Placenta is a tissue formed by the cells from the embryo and the mother." +"T" +"" +"" +"" +"It is formed at around 12 weeks of pregnancy and becomes an important 2" +"structure for nourishment of the embryo. Under normal conditions there" +"ER" +"" +"" +"" +"" +"is no direct flow of blood from mother to the young. The blood systems" +"of the two are separated by thin membranes made up of cells that allow an" +"exchange mainly by diffusion, of oxygen, carbon dioxide, nutrients, and 3" +"waste materials." +"Amnion: Another embryonic membrane, the amnion amnion, grows around the" +"SC" +"" +"" +"" +"" +"embryo itself. The cavity within the amnion becomes filled with fluid called" +"amniotic fluid. The embryo develops in this fluid-filled cavity, which keeps" +"it moist and protects it from minor mechanical injury. Yolksacs edged 4" +"folding of amnion unite at allontois and forms a long tube like structure" +"which connects the embryo with placanta." +"Allantois: Another membrane of the embryo called allantois. This long" +"tubular structure called umbilical cord. It contains the very important blood" +"Free distribution by T.S. Government 2019-20 125" +" 5 vessels that connect the embryo with the placenta. It plays an important" +"role in supplying the food materials from mother to child." +"" +"" +"" +"" +"A" +"Yolk Sac: Yolk sacs encloses a fluid filled cavity. It has no specific functions" +"in placental mammals." +"Thus the embryo develops until it is ready to be born. From the third" +"" +"" +"" +"" +"AN" +"month of pregnancy the embryo is called foetus. Pregnancy lasts, on an" +"average, 9 months, or 280 days. This period is called gestation period." +"Child birth" +"6" +"As pregnancy progresses, the foetus (of an embryo) with additional" +"certain characters grow and the uterus increases in diameter. Usually at" +"" +"" +"" +"" +"NG" +"about the ninth month the head of the foetus is turned down towards the" +"opening of the uterus. During birth, the head usually comes out first." +"Sometimes the feet come first; this makes the delivery more difficult." +"We still do not know much about the mechanism of child birth and how it" +"7 is triggered." +"LA" +"Childbirth begins when the muscle layers of the uterus starts to" +"contract and relax rhythemically these actions are felt as labor pains. At" +"first, muscular activity of the uterus is just strong enough to move the" +"baby slowly toward the vagina, the outer canal of the female reproductive" +"tract. Generally at this stage, the sac (amnion) around the baby breaks, and" +"TE" +"" +"8 its fluid contents are released. This is a good sign that labour is well on its" +"way. Then the contractions of the muscles become stronger and more" +"frequent, and the baby is pushed out of the body through the vagina. Now" +"the baby comes to this world." +"The umbilical cord leading the baby to placenta, is tied off and cut by" +"the doctor. (The small piece of cord remaining attached to the baby shrivels" +"T" +"" +"" +"" +"9 and falls off within a few days. The navel marks the place where it once" +"entered the body.) After the birth of the baby, the" +"ER" +"" +"" +"" +"" +"muscular contractions of the uterus continue until" +"amniotic fluid they push out the tissues of the placenta, which are" +"placenta commonly called the “afterbirth.” During the end" +"amnion of pregnancy, a watery yellowish lymph like fluid" +"umbilical cord called ‘colostrum’ accumulates in the mammary" +"SC" +"" +"" +"" +"" +"glands, which have gradually been enlarging and" +"undergo transformation. For the first few days after" +"the baby is born, the mammary glands secrete only" +"baby colostrum. It is very important to feed this to the" +"new born baby. It helps in developing the immune" +"cervix system of the child. After this milk will be screted." +"fig-17: Shortly before After child birth when production of milk stops" +"birth menstural cycle will be started." +"126 X Class Reproduction - The generating system" +" Do you know?" +"Need for sexual reproduction" +"" +"" +"" +"" +"A" +"Asexual reproduction as we have studied produce organisms which are normally copies" +"of the single parent. Sexual reproduction would require two parents and organism thus" +"" +"" +"" +"" +"AN" +"produced would have a combination of characters of both parents. Asexual reproduction" +"appears to be more efficient as only a single parent is required and no time or energy is" +"spent in finding a mate. But sexual reproduction helps organisms to develop characters" +"that would be of help to them to adapt better their to surroundings. Think of the paramoecium" +"asexual and sexual reproductions mentioned in the begining of the chapter." +"" +"" +"" +"" +"NG" +"When compared with animals sexual reproduction is less complex in" +"most flowering plants. Let us study how does it happen in them." +"Sexual reproduction in flowering plants" +"So far we know about nearly 275,000 species of flowering plants." +"LA" +"With a few exceptions, all of them give rise to seeds enclosed in fruits." +"Most of the plants you are familiar with are mostly flowering plants. Their" +"characters are quite remarkable. The plant size range from trees weighing" +"many tons to tiny water plants about the size of a rice grain. A sal tree" +"growing in the Himalayan moutains, a giant cactus in the Sahara desert, an" +"TE" +"" +"orchid plant on the branch of a jungle tree-all are flowering plants. Now" +"let us examine the sexual reproduction in flowering plants." +"Flower - The reproductive part" +"The reproductive parts of flowering" +"T" +"" +"" +"plants are located in the flower. You have" +"already studied the different parts of the" +"flower- sepals, petals, stamens and carpels." +"ER" +"" +"" +"" +"" +"The reproductive parts of the flower which" +"possess the sex cells or germ cells called" +"stamens and carpels." +"What function do you think is served" +"SC" +"" +"" +"" +"" +"by petals and sepals?" +"Draw the diagram of the flower that" +"you collect and label the parts shown" +"and write their functions." +"Flowers having either stamens or" +"carpels are called unisexual like that of" +"fig-18: Observe structure of" +"bottle gourd and papaya. Flowers having flower and label its parts" +"Free distribution by T.S. Government 2019-20 127" +" both the stamen and carpel are bisexual like Datura. Stamens (male" +"portion called androecium) produce male sex cells in the pollen grain." +"Carpels (female portion, called Gynoecium) produce female sex cells" +"" +"" +"" +"" +"A" +"in ovules inside ovaries. Carpels have three main parts, one to receive" +"the pollen called as stigma, one for passage of compatible male sex" +"" +"" +"" +"" +"AN" +"cells called the style and the other part where fusion of male and" +"female sex cells occur to form zygote, is the ovary." +"fig-18(a):" +"Unisexual Transfer of pollen grains from anther to stigma of the same flower" +"flower is called self-pollination.. Ex: Pea plant. We can see this type of" +"pollination in plants like those of the pea family." +"" +"" +"" +"" +"NG" +"Try to find out some other plants that are self-pollinating types." +"Are there any observable characters that help you to find out" +"whether a plant is self-pollinating type or not? The illustrations given" +"here will help you. If anthers are present below the stigma of the carpel." +"How does the male reproductive cells reach the female" +"LA" +"reproductive cells in flowers of such plants?" +"fig-18(b):" +"Bisexual flower You have studied in earlier classes that how birds and insects help" +"plants as agents of pollination." +"What happens in plants that carry the female reproductive structure or" +"TE" +"" +"the male reproductive structure borne in separate flowers? Remember the" +"flowers of bottle gourd you studied in earlier classes." +"" +"Do you know?" +"Darwin in1876 showed that plants when isolated had the greatest tendency to" +"T" +"" +"" +"" +"self-fertilize while when surrounded by varieties of the same flower, they readily" +"cross fertilize." +"ER" +"" +"" +"" +"" +"When pollen grains of a flower are transferred to the stigma of different" +"flower on the same plant or different plant of the same species, this type" +"of pollination is called cross pollination. Ex: Bottle gourd, Ridged gourd," +"Maize" +"SC" +"" +"" +"" +"" +"Do you know what is self-pollination?" +"Let us now observe some smaller parts that are involved in the process" +"of reproduction in plants. The male reproductive part or the stamen consists" +"of some sac like structures at its head bearing small ball like structures." +"We can easily observe these structures called pollen with the help of hand" +"lens. The pollen grain reach the female reproductive part and fertilize the" +"egg to form a zygote." +"" +"128 X Class Reproduction - The generating system" +" Activity-2" +"Observation of pollen grain" +"" +"" +"" +"" +"A" +"Take a slide and put a few drops of water on it. Now take any flower" +"like hibiscus, tridax, marigold, etc. Tap the anther over the drop of water." +"" +"" +"" +"" +"AN" +"You will see small dot like structures floating on water. These are pollen" +"grains. Observe these first under a hand lens then under a compound" +"microscope." +"You may also see a permanent slide of pollen grain from your lab." +"Observe it under microscope. Make a drawing of what you observed and" +"" +"" +"" +"" +"NG" +"pollen grain" +"compare with the given diagram (fig-19)." +"How many nuclei are present in the pollen grain?" +"pollen tube" +"The given diagram shows two nuclei. Do you think they" +"may have formed if we assume that pollen grain may have" +"started as a single cell stage? The pollen grain germinates nuclei" +"only on the stigma." +"LA fig-19: Pollen grain" +"What happens then? Inorder to find out the remaining" +"process we must look into the structure of the ovule." +"Structure of the ovule stigma" +"An ovule is an egg-shaped structure attached by" +"TE" +"" +"style" +"a stalk to the inner side of the ovary. Depending upon" +"the species of plant involved, an ovary may have one," +"two, several, or even hundreds of ovules. At the center ovary" +"of each ovule there is a microscopic embryo sac ovule" +"filled with food and water. The embryo sac is gametophyte cells" +"composed of gametophyte cells." +"T" +"" +"" +"The majority of flowering plants have an embryo embryo sac" +"sac consisting of seven cells and eight nuclei. At first" +"female gametocyte undergoes series of 3 mitotic" +"ER" +"" +"" +"" +"" +"cell divisions to form eight nucleate stage of fig-20: Structure of gynoecium" +"embryosac. Among these one large central cell" +"contains two nuclei, called polar nuclei. Three cells move towards top end" +"and are called antipodals. Three cells are grouped at micropylar end (place" +"where pollen tube enters) of which two cells of this are called synergids" +"SC" +"" +"" +"" +"" +"and central one is egg cell. Cells on the surface of the stigma secretes a" +"sticky nutrient fluid contains sugars and other substances. This will help" +"the pollengrain to germinate. Then it forms pollen tube. It bears two nuclei." +"Soon after the tip of the pollen tube enters the embryo sac, the end of the" +"tube ruptures and releases the two nuclei into the embryo sac." +"One of the two nuclei fuses with the egg to form a zygote. It is called" +"fertilization. By the time the egg cell has been fertilized, the two polar" +"nuclei combine to form a single fusion nucleus. Now the second male" +"Free distribution by T.S. Government 2019-20 129" +" nucleus deposited in the embryo sac by the pollen tube moves to the center" +"and unites with the fusion nucleus. The zygote will develop into an" +"embryonic plant within the ovule. Union of the fusion nucleus with the" +"" +"" +"" +"" +"A" +"second male nucleus stimulates the formation of a new tissue the" +"endosperm. In which, food materials are stored as development of the" +"" +"" +"" +"" +"AN" +"ovule proceeds." +"" +"stigma" +"" +"pollen tube" +"" +"" +"" +"" +"NG" +"style" +"antipodals" +"" +"" +"" +"ovary polar nuclei" +"integuments" +"LA" +"ovule synergids" +"gametophyte cells egg cell" +"central cell" +"" +"embryo sac fig-22: Female gametophyte" +"TE" +"" +"fig-21: Fertilisation" +"" +"Union of one nucleus with the egg, and the second nucleus with the" +"fusion nucleus is called double fertilization. As far as we know, double" +"fertilization occurs only in flowering plants. After double fertilization," +"the ovule increases in size rapidly as a result of the formation of endosperm" +"T" +"" +"" +"" +"tissue by mitosis and the development of the new embryo. The embryo" +"consists of one or more cotyledons." +"ER" +"" +"" +"" +"" +"The cotyledons develops by utilizing the food stored in endosperm." +"The cotyledons of some flowering plants, beans for example, digest," +"absorb, and store the foods from the endosperm as the ovule is maturing" +"into a seed. As a consequence, the cotyledons become greatly enlarged" +"because of stored food and the endosperm disappears more or less" +"SC" +"" +"" +"" +"" +"completely. Many other flowering plants (such as corn or castor), the" +"endosperm tissue continues to grow as the ovule matures into a seed." +"After fertilisation, the zygote divides several times to form an embryo" +"within the ovule. The ovule develops a tough coat and is generally converted" +"into a seed. The ovary grows rapidly and ripens to form the fruit. Meanwhile" +"the other floral parts may shrivel and fall off." +"" +"130 X Class Reproduction - The generating system" +" Which floral parts may be seen in a fruit?" +"The seed produced after fertilisation contains the future plant or" +"embryo that develops into a seedling under appropriate conditions. The" +"" +"" +"" +"" +"A" +"process is called germination." +"Activity-3" +"" +"" +"" +"" +"AN" +"Seed germination" +"Soak few groundnut or bengal gram (chana) seeds" +"overnight." +"Drain the excess water and cover the seeds with wet cloth." +"" +"" +"" +"" +"NG" +"cotyledon" +"Leave them for a day. Keep sprinkling water at regular intervals plumule" +"so that they do not dry up. Open the seeds carefully and radicle" +"observe the parts, compare with fig-23 to identify the parts." +"How cotyledons are usefull for the plant? Fig-23: Seed germination" +"" +"Observe the life cycle of plant as a whole in the following diagram." +"LA" +"TE" +"" +"fertiliza" +"tion" +"" +"mature plant zygote" +"" +"" +"pollination" +"T" +"" +"" +"embryo" +"ER" +"" +"" +"" +"" +"simple fruit" +"seed" +"seedling germination" +"" +"fig-24: Life cycle of flowering plant" +"SC" +"" +"" +"" +"" +"Do you know?" +"In sexually reproducing organisms usually single fertilization gives rise to zygote." +"In plants there occurs a second fertilization giving rise to a nutritive tissue that provides" +"nutrition to the baby plant which develops from the zygote. The pollen grain has two" +"cells. In one of its cells called a tube cell, there are two nuclei. They travel down" +"" +"Free distribution by T.S. Government 2019-20 131" +" through the stigma and style to the ovary. One of the nuclei fertilizes the egg to form" +"zygote and the other nucleus fertilizes fusion nucleus to form an endosperm which" +"provides food to the baby plant. This is called double fertilization." +"" +"" +"" +"" +"A" +"Cell division and continuation of life" +"" +"" +"" +"" +"AN" +"Continuation of life starts from cells either those of the general body" +"or the sex cells (gametes)." +"Virchow (1821–1902) a proponent of cell theory is given the credit" +"for the phrase Omnis cellula de cellula, or cells arise from pre-existing" +"" +"" +"" +"" +"NG" +"cells, indicates the importance of cell division in the creation of new cells." +"In 1852 a German scientist, Robert Remak, published his" +"observations on cell division, based on his observations of embryos." +"This was one of the first attempts to understand the mechanism of" +"cell division. He stated that binary fission of cells was the means of" +"reproduction of animal cells. What happens during cell division" +"LA" +"could only be understood better when scientists came to know what" +"is present inside the nucleus of the cell." +"In 1879 Walther Flemming (1843–1905) examined many kinds" +"fig-25: of animal and plant cells and selected those that showed division." +"TE" +"" +"Walther Flemming" +"He reported from his observations of such cells that there were" +"string like structures in the nucleus which split longitudinally during cell" +"division. He named such a process of division as mitosis (mitos- means" +"fine threads) as the dividing structures resembled threads. He made a" +"meticulous observation and made sketches and observed that there were a" +"T" +"" +"" +"sequence of events in the process of division. A decade later these thread" +"like structures were named as chromosomes (coloured bodies) as" +"repeatedly in efforts to see them scientists were trying to use dyes to" +"ER" +"" +"" +"" +"" +"stain the nucleus and found that these structures were stained most often." +"His most important discovery was chromosomes appear double in nature." +"Wilhelm Roux (1850-1924) proposed that chromosomes carried a" +"different set of heritable elements and longitudinal splitting observed by" +"SC" +"" +"" +"" +"" +"Flemming, ensured the equal division of these elements. Combined with" +"the rediscovery of Gregor Mendel’s 1866 paper on heritable elements in" +"peas, these results highlighted the central role of the chromosomes in" +"carrying heritable material (or genetic material). In cell division the cell" +"divides into two halves with equal number of chromosomes which are" +"similar to parent cell and are diploid in nature." +"But the chromosomes number always remained the same. Biologists" +"132 X Class Reproduction - The generating system" +" also began to wonder about this. When cells divide, the daughter always" +"have the same number of chromosomes as the parent cell. Let us assume" +"that cell division is always preceded by mitosis. In case of man egg cells" +"" +"" +"" +"" +"A" +"and sperm cells like other cells, must contain 46 chromosomes. But if" +"this were so, then the union of egg nucleus and sperm nucleus , which" +"" +"" +"" +"" +"AN" +"takes place during fertilization would produce a total of 92" +"chromosomes in zygote. If it continues this would be 184, 368 and" +"so on. But the situation is not like that." +"August Weismann (1834-1914) a biologist hypothesised that" +"1. In successive generations, individuals of the same species have" +"" +"" +"" +"" +"NG" +"the same number of chromosomes." +"2. In successive cell division the number of chromosomes always fig-26:" +"August Weismann" +"remain constant." +"" +"Do you know?" +"LA" +"August Weismann was a scientist with poor eye sight, it was difficult for him to" +"use a microscope to study cells. But there were other things that he could do." +"Advancement of science is not only possible by mere collection of data. Someone" +"must think, analyse and interpret the data. August Weismann’s poor eyesight forced" +"TE" +"" +"him to spend time thinking. Think how great he was!" +"" +"The scheme of mitotic division was confirmed in 1904 by Theodor" +"Boveri (1862–1915). The chemical nature of the genetic material was" +"determined after a series of experiments over the next fifty years," +"T" +"" +"" +"" +"bone Two kinds of cell division in the life of" +"muscle an individual. The chromosome" +"numbers 2n and n are respectively the" +"ER" +"" +"" +"" +"" +"skin" +"number of chromosomes following" +"nerve mitosis (2n) and half the number (n)" +"gland following meiosis - the type of" +"division predicted by Weismann." +"blood" +"mitosis" +"other cells" +"SC" +"" +"" +"" +"" +"meiosis" +"sperm sperm" +"" +"" +"egg fertilised immature" +"egg reproductive cell egg" +"" +"" +"fig-27: Cell division" +"" +"Free distribution by T.S. Government 2019-20 133" +" culminating in the determination of its structure the deoxy ribonucleic" +"acid (DNA) in 1953 by James Watson(DNA) and Francis Crick. Scientists" +"proved that mitosis takes place in all body cells which retains same number" +"" +"" +"" +"" +"A" +"of chromosomes. Meiotic division takes place in sex cells where the" +"chromosome number is halved. Observe the fig-27." +"" +"" +"" +"" +"AN" +"Cell division in Human beings" +"We know that cell as the structural and functional units of life of any" +"organism. In all organisms the cell divide and form new cells. The process" +"of cell divisoin is same in unicellular organisms and highly evolved" +"" +"" +"" +"" +"NG" +"multicellular organisms like human being." +"Cell division is the process that transforms a human fertilized egg" +"into a baby in nine months and into an adult in the next 20 years. Cell" +"division and function in a multicellular organism is highly regulated. It" +"occurs only when there is a need for it." +"Cells in some organs, such as heart and brain of an individual never" +"LA" +"divide. On the other hand bone marrow cells actively divide to produce" +"red blood cells, which have a short life span 120 days in the body. For" +"example, if you cut your finger and bleed, soon a blood clot forms to stop" +"the bleeding. This brings in various chemicals to the site that stimulate" +"TE" +"" +"skin cells to divide and heal the wound. Cell division ceases as the wound" +"is completely healed. In contrast, cancer cells do not respond to such" +"growth regulating factors and continuously divide at the expense of normal" +"cells, thus ultimately killing the host. So it becomes important to" +"understand the processes involved in cell division. The cell cycle will help" +"T" +"" +"" +"us understand this better." +"Cell cycle" +"M (1 hr)" +"ER" +"" +"" +"" +"" +"G2 (3.5 hrs) The process of cell division is called" +"M" +"‘Mitosis’, which is completed in 40 to 60" +"G2 minutes (this is the time of active" +"division). The period between two cell" +"divisions is called ‘Interphase’. This is" +"G1" +"SC" +"" +"" +"" +"" +"actually the period when the genetic" +"S" +"material makes its copy so that it is" +"equally distributed to the daughter cells" +"S (10.5 hrs) during mitosis. Interphase can be divided" +"into three phases." +"G1 (10.5 hrs)" +"1) G1 phase: This is the linking period" +"fig-28: Interphase between the completion of mitosis and" +"134 X Class Reproduction - The generating system" +" the beginning of DNA replication (Gap 1 phase). The cell size increase" +"during this period." +"2) S phase: This is the period of DNA synthesis (Synthesis phase) leading" +"" +"" +"" +"" +"A" +"duplication of chromosomes." +"3) G2 phase: This is the time between the end of DNA replication and the" +"" +"" +"" +"" +"AN" +"beginning of mitosis.(Gap 2 phase). Cell organelles divide and prepare" +"chromosome for mitosis." +"M phase: This is mitotic cell division phase. It includes prophase," +"metaphase, anaphase, telophase and cytokinesis." +"To understand the functional relationship between these phases, Potu" +"" +"" +"" +"" +"NG" +"Narasimha Rao and Johnson (see annexure) conducted some experiments" +"using the cell fusion technique. That is combining two cells in experimental" +"conditions. With this cell fusion technique Johnson and Potu Rao revealed" +"for the first time the structure of interphase(GI, S and G2) chromosomes" +"that are not ordinarily visible under the microscope. They provided evidence" +"on progression of cells through the cell cycle in sequential unidirectional" +"LA" +"and controlled way by a series of chemical signals that can diffuse freely" +"between nucleus and cytoplasm. These experiments are considered to be" +"a ‘mile stone’ in the cell cycle studies." +"Activity-4" +"TE" +"" +"Observe different stages of mitotic cell division" +"Take permanent slides which shows different stages of mitotic cell" +"division from your lab kit. Observe carefully under microscope. Draw" +"diagrams what you observe, and compare your observations with the" +"following figures. (Fig-29)" +"T" +"" +"" +"" +"The division of nucleus (Karyokinesis) followed by the division of" +"Cytoplasm (Cytokinesis) finally brings about formation of two daughter" +"ER" +"" +"" +"" +"" +"cells. While observing cells in tissues undergoing division, it is not easy" +"to differentiate different stages of division. Observe the table-1." +"SC" +"" +"" +"" +"" +"Prophase Metaphase Anaphase Telophase" +"fig-29: Mitosis" +"" +"Free distribution by T.S. Government 2019-20 135" +" Table-1: Mitosis" +"Stage Description" +"1. Prophase 1. Chromosomes condense and get coiled. They become visible even in" +"" +"" +"" +"" +"A" +"light microscope and nucleoli become smaller." +"2. Chromosomes split lengthwise to form chromatids, connected by" +"" +"" +"" +"" +"AN" +"centromeres." +"3. Nuclear membrane disappears." +"4. Centrosome, containing rod-like centrioles, divide and form ends of" +"spindle (probably animal cells only)." +"(Note: No pairing of chromosomes as in meiosis)." +"" +"" +"" +"" +"NG" +"2. Metaphase 1. Chromosomes move to spindle equator, spindle fibres attached to" +"centromers." +"1. Centromeres split, separating the chromatids." +"3. Anaphase 2. Spindle fibres attached to centromeres contract, pulling chromatids" +"towards poles" +"4. Telophase" +"LA" +"1. Chromatids elongate, become invisible, replication at this stage to" +"become chromosomes." +"2. Nuclear membranes form round daughter nuclei." +"3. Cell membrane pinches to form daughter cells (animals) or new" +"TE" +"" +"cell wall material becomes laid down across spindle equator (plants)" +"4. Nucleus divides into two and division of cytoplasm starts Two cells" +"are form." +"" +"Process of meiosis" +"Unlike mitosis which is a continuous process for division in most" +"T" +"" +"" +"cells. Meiosis occurs only during the formation of gametes in sexual" +"reproduction. Meiosis has two phases. During the first phase of meiosis" +"ER" +"" +"" +"" +"" +"the parent cell (containing two sets of chromosomes) divides twice, though" +"the chromosomes divide only once. The second phase of meiosis is similar" +"to normal mitosis, but chromosomes do not duplicate, more over the" +"SC" +"" +"" +"" +"" +"Prophase 1 Metaphase 1" +"Anaphase 1 Telophase 1" +"fig-30: Meiosis Daughter cells" +"" +"136 X Class Reproduction - The generating system" +" chromosomes are distributed equally to each cell. Thus the four daughter" +"cells have just half the number of chromosomes of the gamete mother" +"cell. These are haploid (containing only one set of chromosome). Thus" +"" +"" +"" +"" +"A" +"this division is also called reduction division. You will learn more about" +"this in further classes." +"" +"" +"" +"" +"AN" +"What differences do you find in mitosis and meiosis? Write in a" +"tabular form." +"What would happen if the gamets do not have half the chromosome" +"number as to their parental cell?" +"How would it affect the progeny formed by sexual reproduction?" +"" +"" +"" +"" +"NG" +"Reproductive health" +"Why did the government of India fixed the legal marriage age of" +"boys (21 years) and girls (18 years)?" +"Do you feel that it is a social responsibility to control birth after" +"having one or two children?" +"LA" +"What do you understand by the term ‘Healthy Society’?" +"Will you encourage child marriage? Why?" +"As we have seen, the process of sexual maturation is gradual, and takes" +"TE" +"" +"place while general body growth is still going on. Therefore, some degree" +"of sexual maturation does not necessarily mean that the body or the mind" +"is ready for sexual acts. Further, it is not fit for having and bringing up" +"children. How do we decide if the body or the mind is ready for this major" +"responsibility? All of us are under many different kinds of pressures about" +"these issues. There can be pressure from our friends for participating in" +"T" +"" +"" +"" +"many activities, whether we really want or not. There can be pressure from" +"families to get married and start having children. There can be pressure" +"ER" +"" +"" +"" +"" +"from government and voluntary organisations to avoid having children. In" +"these situations, making right choices is important." +"In the lesson 8th class “why do we fall ill”, we learnt that the diseases" +"can be transmitted from person to person in a variety of ways. Since the" +"sexual act is a very intimate connection of bodies, it is not surprising that" +"SC" +"" +"" +"" +"" +"many diseases can be sexually transmitted. These include bacterial" +"infections such as Gonorrhoea and syphilis, and viral infections such as" +"AIDS (Acquired Immuno Deficiency Syndrome)." +"fig-31:" +"What is the virus which causes AIDS? Red ribbon" +"These diseases spread by unsafe sexual contacts, using infected devices, 1st December" +"infected blood transfusion, from an infected mother to child. AIDS Day" +"" +"Free distribution by T.S. Government 2019-20 137" +" It is very sad to say Telangana and Andhra Pradesh have the highest" +"number of HIV positive patients in the country. According to survey" +"conducted by Ministry of Health and Family Welfare, the state had 24" +"" +"" +"" +"" +"A" +"lakh HIV positive patients in the country during 2011-12." +"Maharashtra, Karnataka and Telangana are followed by Andhra Pradesh." +"" +"" +"" +"" +"AN" +"Officials said that one in every 300 adults is suffering from HIV elsewhere." +"The prevalence of HIV is 1.07 percent among males and 0.73 among" +"female in the state, which again is higher than other states. Its prevalence" +"among adults (15-49 years) 0.90 percent, pregnant women 1.22 percent" +"in Andhra Pradesh." +"" +"" +"" +"" +"NG" +"Illiteracy, poor health, unemployment, migration, non-traditional sex" +"practise, unethical contacts and trafficking are some of the factors" +"contributing to the spread of HIV in the state, according to experts." +"The government established Anti Retroviral Therapy (ART centres) to" +"supply medicine to HIV patients. Medical and health, family health" +"LA" +"departments AIDS control projects implementing various programmes like" +"ASHA (Accredited Social Health Activist), Red Ribbon Express, etc., to" +"create awareness in society on the risks and symptoms of AIDS." +"Invite local health worker to your school and discuss about HIV" +"and its impact on society." +"TE" +"" +"Social discrimination against AIDS patients is also a social evil." +"Can you support this? Why?" +"If we follow the simple life styles as cited below one could avoid" +"many sexually transmitted diseases." +"Avoid sex with unknown partners or multiple partners" +"T" +"" +"" +"Even though contraceptives are available it is better follow ethical and" +"healthy life practices." +"ER" +"" +"" +"" +"" +"In case of doubt, go to a qualified doctor for early detection and get" +"complete treatment if diagnosed with disease." +"Birth control methods" +"The sexual act always has potential to lead to pregnancy. Pregnancy" +"will make major demands on the body and the mind of the woman, and if" +"SC" +"" +"" +"" +"" +"she is not ready for it, her health will be adversely affected. Therefore," +"many ways have been devised to avoid pregnancy." +"The prevention of pregnancy in women by preventing fertilisation is" +"called contraception. Any device or chemical (drug) which prevents" +"pregnancy in woman is called a contraceptive. The birth control methods" +"can be of various types and can be used by any of the partners as preferable." +"Physical devices such as condoms and diaphragm (cap) are used. This" +"138 X Class Reproduction - The generating system" +" prevents reaching of sperms to ova for fertilisation. This device not only" +"prevents fertilisation but also transmitting some sexually transmitted" +"diseases (STD) like gonorrhoea, syphilis and AIDS. No other method of" +"" +"" +"" +"" +"A" +"contraception provides protection against sexually transmitted diseases." +"Chemicals in the forms of pills are induced either orally or inserting into" +"" +"" +"" +"" +"AN" +"female reproductive organ vagina. It contains hormones which stop the" +"ovaries from releasing ovum into the oviducts. Now a days pills for males" +"are also available. These pills kill the sperms and hence are called spermicides." +"" +"blood supply" +"" +"" +"" +"" +"NG" +"vasdeferens" +"epididymis small incision" +"testis" +"cauterised tied and cut banded" +"copper - T vasectomy - cut ends of tubectomy - cut ends of" +"vas deferens are sealed follopian tubes are sealed" +"fig-32: Birth control methods" +"LA" +"The use of intra-uterine device called copper-T, loop etc. are also very" +"effective in preventing pregnancy. If a woman uses a copper-T as a method" +"of contraception for avoiding unwanted pregnancies, they cannot protect" +"her from acquiring sexually transmitted diseases. Surgical methods of birth" +"TE" +"" +"control are available for males as well as females. In males a small portion" +"of vas deferens (sperm ducts) is removed by surgical operation and both" +"ends are tied properly. This method is called vasectomy. In females a small" +"portion of oviducts (fallopian tube) is removed by surgical operation and" +"the cut ends are tied. This prevents the ovum from entering into the" +"oviducts. This method is called tubectomy." +"T" +"" +"" +"Fighting against social ills" +"Teenage motherhood" +"ER" +"" +"" +"" +"" +"We have studied how complicated the process of reproduction is. Child" +"birth is even more complicated. Understanding it and getting prepared for" +"it needs maturity of the mind and body. Illiteracy, Poverty, Supersitions" +"are the main reasons for early child marriage. Thus a girl only after 18" +"years of age can be said to be prepared for the same. Most of the times" +"SC" +"" +"" +"" +"" +"this age is also dangerous to the girl. According to the department of family" +"welfare 21% of teenage mothers die during delivery. Malnutrition is also" +"one of the reason for it. So girls below 18 years of age should not be" +"marry." +"Stop female foeticide" +"Who knows today’s girl child may become a great scientist, a famous" +"doctor, a top class engineer, a dedicated administrative officer, a world" +"Free distribution by T.S. Government 2019-20 139" +" renowned economist, a wonderful teacher of an unmatched world leader" +"of tomorrow. Stop female foeticide! Save the girl child." +"Due to reckless female foeticide the male female child sex ratio is" +"" +"" +"" +"" +"A" +"declining at an alarming rate in some sections of our society. Our" +"government has already enacted laws to ban on determination of sex of" +"" +"" +"" +"" +"AN" +"foetus. In spite of laws it’s a social responsibility of us to prevent female" +"foeticide." +"Why doctors are prohibited to do sex determination through" +"ultrasound scanning for pregnant women?" +"We know that if health is lost, everything is lost. It’s our responsibility" +"" +"" +"" +"" +"NG" +"to be healthy and to make others realise the importance of health. Sound" +"body is to sound mind. To be an ideal citizen of India we should have" +"knowledge of reproductive health not only to control high population" +"growth but to create a healthy society." +"LA" +"Key words" +"" +"Progeny, cyst, fragmentation, regeneration, vegetative propagation, artificial" +"propagation, parthenogenesis, cutting, layering, grafting, stock, scion, desirable" +"TE" +"" +"characters, tissue culture, amniotic fluid, placenta, umbilical cord, mitosis, meiosis," +"chromatids, chromosome, foeticide, HIV-AIDS, vasectomy, tubectomy." +"" +"" +"What we have learnt" +"T" +"" +"" +"Reproduction is necessary for perpetuation and continuation of life." +"Reproduction is of two types keeping in view of fusion of gametes- Sexual and Asexual." +"ER" +"" +"" +"" +"" +"In sexual reproduction only half of each parent’s chromosomes are passed to the next generation." +"Fission, budding, fragmentation, regeneration, spore formation are the ways of asexual reproduction." +"Several plants may be grown from vegetative parts like stems, roots, leaves etc and is called" +"vegetative propagation." +"Vegetative propagation may be natural or man made. It has got some economic importance." +"SC" +"" +"" +"" +"" +"In grafting we can acquire desirable characters of plants." +"Tissue culture is a modern technique of growing plants. It helps to grow more plants in less time and" +"place." +"Sexual reproduction in higher animals is through specialised organs, distinctively male and female" +"reproductive systems." +"Cells divide for growth of the individual to repair and replace the worn out cells and also for the" +"formation of gametes." +"140 X Class Reproduction - The generating system" +" Cell division is of two types-a) Mitosis-or somatic cell division B) meiosis-or reproductive cell division." +"The cell of the body may either be somatic cells that constitute the general body of the organism or" +"germ cells that take part in formation of gametes." +"" +"" +"" +"" +"A" +"G-1, G-2, S and M are the stages in a cell cyclic which occur in a manner." +"The longest phase is the synthesis phase in cell cycle where duplication of genetic material takes place." +"" +"" +"" +"" +"AN" +"At the end of mitosis two daughter cells are formed with the number of chromosomes same as that" +"of their parents. It runs through Prophase, Metaphase, Anaphase and Telophase." +"Division of cytoplasm is called Cytokinesis." +"During meiosis the parent cell divides twice and four daughter cells are formed." +"Reproductive health is important to possess sound mind in a sound body." +"" +"" +"" +"" +"NG" +"One should be aware of the facts related to transmission of sexually transmitted diseases." +"There is no cure for AIDS. Prevention is the only way to avoid it." +"Now a days various methods of contraception are available to control child birth." +"It is our responsibility to build a healthy society." +"Determination of sex before birth is illegal." +"Stop female foeticide." +"LA" +"Improve your learning" +"1. Why do fish and frog produce a huge number of eggs each year?(AS1)" +"TE" +"" +"2. Give examples and explain what is meant by external fertilisation?(AS1)" +"3. Write differences between.(AS1)" +"a) Grafting - Layering b) stamen-carple" +"4. Explain the process of fertilisation in plants.(AS1)" +"5. What are the different modes of asexual reproduction? Cite them with examples.(AS1)" +"T" +"" +"" +"" +"6. In what ways does sexual reproduction differs from asexual one? State at least three reasons.(AS1)" +"7. How are sperm cells adapted for their function?(AS1)" +"ER" +"" +"" +"" +"" +"8. The menstrual cycle prepares the uterus for a fertilised egg. How long is an average menstrual" +"cycle from start to finish?(AS1)" +"9. When the foetus is growing inside the uterus it needs nutrients. What provides these nutrients?(AS1)" +"10. Which type of substances are obsorbed by foetus from the mother ?(AS1)" +"SC" +"" +"" +"" +"" +"11. What is the job of the amniotic sac?(AS1)" +"12. What are the advantages of sexual reproduction?(AS1)" +"13. How does reproduction help in providing stability to population of species?(AS1)" +"14. Write the differences between mitosis and meiosis.(AS1)" +"15. What happens to the wall of the uterus during menstruation?(AS1)" +"16. “All unicellular organisms undergo only mitotic cell division during favourable conditions”- Do you" +"support this statement? Why?(AS2)" +"Free distribution by T.S. Government 2019-20 141" +" 17. Vicky’s father wants to grow a single plant having two desirable characters colourful flowers and" +"big fruits What method will you suggest him and why?(AS3)" +"18. Uproot an onion plant and take a thin section of its root tip. Stain it and observe under microscope." +"" +"" +"" +"" +"A" +"Draw as you see and identify the stages of the cell division.(AS3)" +"19. Visit a nearby village and collect information how farmers grow sugarcane, flowering plants like" +"" +"" +"" +"" +"AN" +"chrysanthemum, primerose and vegetables like stem tubers, plump gourd (dondakaya) etc. Make" +"a report and present in class.(AS4)" +"20. Collect information from school library or using internet what vegetative methods are followed in" +"your district as well as in your state to propagate various plants of economic importance. Represent" +"it in a graph.(AS5)" +"" +"" +"" +"" +"NG" +"21. Make a flow chart to show the cell cycle and explain cell division describing different stages of" +"mitosis.(AS5)" +"22. Draw neat labelled diagrams of male and female reproductive system of plant.(AS5)" +"23. Observe the following part of a flowering plant prepare a note.(AS5) stigma" +"style" +"24. Prepare a flow chart to explain the process of sexual reproduction in" +"LA" +"plants.(AS5) ovary" +"25. Draw a neatly labled diagram to explain plant fertilisation. Write few ovule" +"gametophyte" +"points on pollen grain.(AS5) cells" +"26. What would be the consequences if there is no meiosis in organisms that embryo sac" +"TE" +"" +"reproduce sexually?(AS2) Q.No.23" +"27. How will you appreciate cell division that helps in perpetuation of life? (AS6)" +"28. What precautions will you take to keep away from various sexually transmitted diseases?(AS7)" +"29. Conduct a seminar on child marriages and foetiside.(AS7)" +"" +"Choose the correct answer" +"T" +"ER" +"" +"" +"" +"" +"1. The part of the female reproductive system that produces the eggs? ( )" +"A) Ovary B) Epididymis C) Cervix D) Fallopian tube" +"2. The term that we use to describe a sperm cell fusing with an egg cell? ( )" +"A) Fragmentation B) Fermentation C) Fertilisation D) Fusion" +"3. Which part of the male reproductive system produces (human) the sperm cells? ( )" +"SC" +"" +"" +"" +"" +"A) Vasdeference B) Epididymis C) Seminiferous tubulesD) Scrotum" +"4. How does the sperm break through the egg cell membrane? Choose the option you think is right." +"A) Tears a hole in the membrane B) Dissolves the membrane with chemicals ( )" +"C) Bites through the membrane with teeth D) Squeezes through gaps in the membrane" +"5. Why are egg cells larger than sperm cells? Choose the option you think is right. ( )" +"A) Egg cells have more cells in them B) Have food store to help growth after fertilisation" +"C) Have thicker cell membranes D) Have larger nuclei" +"142 X Class Reproduction - The generating system" +" 6. Which of these things will affect the way a foetus grows? Choose the option you think is right." +"( )" +"A) Chemicals in cigarette smoke B) Alcohol C) Drugs D) All of the above" +"" +"" +"" +"" +"A" +"7. Which of the following is the correct sequence of steps in the human life cycle? Choose the right" +"option. ( )" +"" +"" +"" +"" +"AN" +"A) Babyhood, childhood, adolescence, adulthood" +"B) Childhood, babyhood, adulthood, adolescence" +"C) Adolescence, babyhood, adulthood, childhood D) None of these" +"" +"Annexure" +"" +"" +"" +"" +"NG" +"Dr. Potu Narasimha Rao, a renowned scholar and an eminent" +"cytologist came from a poor family in Muppalla village of Guntur" +"district. He completed his graduation in Agriculture and did his" +"MS at IARI, New Delhi. Later, he went to USA for research. He" +"LA" +"worked on the cytogenetics of tobacco plant. During his research," +"a cell line called Hela, isolated from a human tumour was established" +"in 1952 and received his PhD in 1963. He switched his attention" +"from plant cytogenetic to the field of cancer cells. He conducted Dr. Potu" +"Narasimha Rao" +"TE" +"" +"research in cell kinematics and studied extensively on the ‘triggering" +"factor’ of cell division i.e mitosis." +"He found that human cells either normal or cancer cells in" +"culture media usually divide every 20 to 24 hours. But actually" +"normal mitosis is completed in 40 to 60 minutes. The period" +"in between two cell divisions is called interphase. The" +"T" +"" +"" +"" +"interphase further consists of 3 phases G1, S and G2 phases." +"To understand the functional relationship between these" +"ER" +"" +"" +"" +"" +"phases of cell cycle. Dr.N.Rao and his research associate" +"Dr.Johnson conducted experiments on cell fusion technique." +"He La Cell His researches revealed that the cell cycle is sequential" +"Unidirectional and controlled by a series of chemical signals. His experiments are" +"considered to be a milestone in the cell cycle studies.This study threw a new hope of ray" +"SC" +"" +"" +"" +"" +"for the budding scientists to carry out researches on cell division. If you want to talk to this" +"great scientist log in with email poturao@yahoo.com" +"" +"Read the poem ‘Maa Mujhe Ane Do’in your Hindi book." +"Collect information about Rashrtriya Kishore Swasthya Karakram (RKSK)" +"" +"" +"Free distribution by T.S. Government 2019-20 143" +" A" +"Chapter" +"" +"" +"" +"" +"AN" +"7" +"" +"" +"NG" +"Coordination in life processes" +"LA" +"Human body is a wonderful machine. It is a complicated structure than" +"it appears. Did you ever imagine the complexity of your body? Different" +"life processes in living organisms like respiration, digestion, blood" +"circulation, excretion, nervous system etc., are inbuilt in our body at their" +"TE" +"" +"specific places and carry out their specific functions in a coordinated" +"manner. We have studied each of the processes in detail nearly in isolation" +"except in the chapter on ‘Control and Coordination’. In this chapter, we" +"shall go a step further to experience the complexities involved and" +"appreciate the wonderful integration in our life processes." +"Let’s recall the parts of the digestive canal or gut, that are involved in" +"T" +"" +"" +"" +"the digestive process where the food is broken down at different stages." +"Write down the parts of the gut where the journey of food starts" +"ER" +"" +"" +"" +"" +"from mouth to anus." +"Which type of life processes would be involved in the breakdown of" +"food in the stomach?" +"If any of those processes fail to function, what affect would it have" +"SC" +"" +"" +"" +"" +"on our body?" +"Every process is dependent on other to keep the body in good" +"condition. To understand this concept we analyze how digestive system is" +"coordinated with other systems as an example. We shall study the digestive" +"system from feeling hungry to utilization of food (converting in to energy)," +"illustrating the inter connected processes going on in our body." +"" +"144 X Class Coordination in life processess" +" Feeling Hungry" +"How do we know that we need food?" +"" +"" +"" +"" +"A" +"Activity-1" +"Let us observe the following table. Identify and tick those options that" +"" +"" +"" +"" +"AN" +"you think makes you feel hungry. Discuss with your friends." +"Table-1" +"Smell of Taste of Sight of Being tired Need of Thought of" +"food food food and exhausted food food" +"" +"" +"" +"" +"NG" +"What stimulates hunger?" +"esult of stimulation of hunger?" +"What would be the result" +"LA" +"Which system do you think would send the signals to make us realize" +"that we are hungry?" +"Well, a major cause for feeling hungry lies in the physiology of blood" +"circulation. Levels of different substances are generally maintained in the" +"TE" +"" +"blood mainly by our digestive system. One of the major substances is" +"glucose. When its levels in the blood fall, we get hunger pangs in stomach." +"This again involves production of a series of proteins, some of which are" +"hormones like Ghrelin. Secretion of the hormone “Ghrelin” starts in the" +"empty. Ghrelin is secreted from certain cells in the" +"stomach when it goes empty." +"T" +"" +"" +"wall of the stomach. Hunger contractions (hunger pangs) start to occur in" +"the stomach due to hunger generating signals that reach the brain from the" +"ER" +"" +"" +"" +"" +"stomach due to the secretion of this hormone. It is believed that the" +"Diencephalon in fore brain and vagus nerve (10th cranial nerve) plays an" +"important role in carrying these signals to the brain. Hunger pangs continue" +"up to 30- 45 minutes. Increase in ghrelin levels results in sensation of" +"hunger and motivation to consume food." +"SC" +"" +"" +"" +"" +"Which nervous system controlls the hunger pangs." +"What kinds of controls are exercised during sensation of hunger?" +"Are they hormonal or neural or both?" +"Can you suggest any 4 systems involved in the process of generating" +"hunger sensation?" +"When you feel your stomach is full and there is no need of food any" +"Free distribution by T.S. Government 2019-20 145" +" more, another hormone leptin is secreted that suppresses hunger." +"Usually we take food at a particular time. Every day we usually start" +"feeling hungry at that time. You may have experienced this in your school" +"" +"" +"" +"" +"A" +"during lunch hour." +"Outcome of sensation of hunger" +"" +"" +"" +"" +"AN" +"We find that different organ systems are involved in the digestive" +"process." +"Let us find more about how the organ systems are involved. Feeling" +"hungry leads us to consume food. Sometimes you may have often" +"" +"" +"" +"" +"NG" +"experienced that stale food is out rightly rejected even before intake." +"What plays a major role to identify stale food?" +"If you are having a tasty dish do you think the smell of it increases" +"your appetite?" +"Taste and smell are closely related" +"LA" +"Taste and smell are intimately entwined. This close relationship is most" +"apparent in how we perceive the flavours of food. Anyone with severe" +"cough and cold can not make out the difference in tastes of certain food" +"items. Actually, what is really being affected is the flavour of the food, or" +"TE" +"" +"the combination of taste and smell. That’s because only the taste, not the" +"food odours, are being detected. Taste itself is focused on distinguishing" +"chemicals that have a sweet, salty, sour, bitter, or umami taste (umami is" +"Japanese for ‘savory’). However, interactions between the senses of taste" +"and smell enhance our perceptions of the foods we eat." +"T" +"" +"" +"The following activity helps us to observe how taste is affected by the" +"sense of smell." +"ER" +"" +"" +"" +"" +"Activity-2" +"Chewing, cumin ((Jeera), sounf (fennel seeds), potato and apple" +"First close your nose with your fingers. Pop in some Jeera in your" +"mouth and chew it for some time. After that, chew some sounf. Could you" +"SC" +"" +"" +"" +"" +"recognize the taste? How long has it taken to know the taste? After some" +"time wash your mouth and repeat the activity by chewing a piece of an" +"apple followed by a potato(remember to close your nose)." +"What are your observations?" +"To conclude, if you want to taste the food material, the food should" +"dissolve in saliva. On the other hand, we can taste the food that is in the" +"form of liquid only. We know that different types of taste buds are present" +"146 X Class Coordination in life processess" +" on the tongue. You have also learnt about different types circumvallate papillae" +"of papillae (taste buds) on the tongue for different tastes foliate papillae" +"in ninth class. Let us recall them. Only after the" +"" +"" +"" +"" +"A" +"dissolved food enters into the cup like taste buds, the" +"sense of taste is carried to the brain for analysis. Then" +"" +"" +"" +"" +"AN" +"only we will know the taste of the food material." +"fungiform papillae filiform papillae" +"Could you know the taste of both or did it taste" +"fig-1: Papillae on tongue" +"the same? Why?" +"When we smell, the air borne substances get dissolved in the watery" +"film of nasal mucus. The chemoreceptors in nose are other wise called" +"" +"" +"" +"" +"NG" +"olfactory receptors which trigger signals in the form of nerve impulses to" +"the brain where smell is detected. Similarly as we take food into our mouth" +"the taste buds sends signals to the brain. Picking up the slight differences" +"in smell the food tastes are identified in our brain." +"What happens when we put a food material in our mouth?" +"LA" +"Name the parts in the mouth that help us to taste food." +"Let’s find out more about the role of these parts." +"Activity-3" +"TE" +"" +"Take a pinch of asafoetida powder or garlic and rub it on hand kerchief" +"or tissue paper." +"Close your eyes and smell it. Then try to identify taste of different" +"types of food materials with the help of your friend." +"Does garlic have a stronger scent than apple? How do you think" +"T" +"" +"" +"the stronger scent affect your sensation of taste?" +"How many food materials you have identified correctly?" +"ER" +"" +"" +"" +"" +"Write a few lines on relation between smell and taste?" +"Have you ever felt that a particular food is tasty just by looking at" +"it?" +"Sometimes mouth starts watering just by hearing the name like" +"SC" +"" +"" +"" +"" +"tamarind / lime / mango etc.," +"Now let us summarize the result of the activities with the help of your" +"answers. In general, we prefer the food material, which is attractive to our" +"eyes, and flavour to nose, then we taste it." +"Therefore, when we eat, without our knowledge, we use our sight, nose" +"and tongue for selecting food for ingestion." +"" +"Free distribution by T.S. Government 2019-20 147" +" Russian scientist, Ivan Pavlov has conducted experiments and found" +"that even the thought of food will water your mouth (conditioned reflexes)." +"You have discussed about Pavlov experiment in the chapter animal behavior" +"" +"" +"" +"" +"A" +"in class 9th." +"Are there any other sensation that affect taste?" +"" +"" +"" +"" +"AN" +"What happens to your taste sensation while sipping hot milk or tea?" +"You may also find something more tastey when they are hot. While" +"some others are relished cool." +"What do you think could be the range of temperature for us to relish" +"" +"" +"" +"" +"NG" +"food items?" +"Taste is something connected to the tongue and the palate" +"Let us do a simple activity to see the role of different parts of the" +"mouth in helping us to taste." +"LA" +"Activity-4" +"Sugar crystals over the tongue" +"Place some sugar crystals on your tongue keep your mouth opened" +"and see that your tongue doesn’t touch the palate. Record the time from" +"TE" +"" +"the moment you placed the crystals on your tongue till you got the taste" +"by using stop watch." +"Now repeat the test by placing the sugar crystals on the tongue" +"palate and pressing it against the palate. Record the time from placing" +"sugar crystals to getting the taste .Or put a drop of sugar solution" +"T" +"" +"" +"tongue" +"on your tongue using a dropper." +"Can we taste on dry tongue?" +"ER" +"" +"" +"" +"" +"fig-2: Tongue" +"and palate Which way helped you taste faster ? Why?" +"Based on the above activity we know that taste can be identified easily" +"when the tongue is pressed against the palate. As we know the tongue is" +"sensory in function and contains taste buds. These taste buds are tiny" +"SC" +"" +"" +"" +"" +"papillae with an opening on top. Within them there are several taste sensitive" +"cells. Any food substance when placed on the tongue gets dissolved in the" +"saliva secreted by salivary glands in the mouth. When the tongue is pressed" +"against the palate the food substance is pressed against the opening of the" +"taste bud letting it to reach the taste cells and triggering taste signals." +"Finally the taste is recognized in the brain." +"" +"" +"148 X Class Coordination in life processess" +" Observe the flow chart what it indicates about the taste sense?" +"" +"Taste Nose Mouth Tongue" +"" +"" +"" +"" +"A" +"AN" +"Brain Olfactory receptors Salivary glands Taste buds" +"" +"" +"" +"What do you think would happen if the salivary glands do not" +"" +"" +"" +"" +"NG" +"function in our mouth?" +"Suppose your taste buds were affected what would happen to your" +"interest in having food?" +"Mouth - the munching machine" +"LA" +"Would you be able to comfortably munch your food if you had lost" +"some of your teeth?" +"Activity-5" +"To show break down of food by using the model of chalkpiece" +"TE" +"" +"kept in vinegar" +"Break a piece of chalk into two halves. Crush one half to tiny pieces" +"leaving the other as it is. Take two small mineral water bottles (1/2 ltr bottle)" +"cut them into two equal halves and discard the upper portion. Now we have" +"two beakers from the lower cut portion." +"T" +"" +"" +"" +"Fill them half with vinegar and add the crushed chalk to one beaker and" +"the other uncrushed half chalk to the other. Obseve them after half an hour" +"ER" +"" +"" +"" +"" +"or so." +"Which one dissolved faster the crushed chalk or the whole one ?" +"The above experiment tells us the need of mechanical crushing of food." +"Hence the food in the mouth has to be broken down into tiny pieces to" +"SC" +"" +"" +"" +"" +"increase the surface area for action of substances that aid in digestion." +"How does this process of mechanical crushing go on in the mouth?" +"Which parts in the mouth are involved in this?" +"What are the systems involved in this process?" +"You know that teeth helps in chewing food material. Let us know about" +"different types of teeth in our mouth and how they helps in digestive process." +"Free distribution by T.S. Government 2019-20 149" +" Activity-6" +"Observe the model or chart of jaw, how are" +"}" +"" +"" +"" +"" +"A" +"molars (3) the teeth arranged? Are all the teeth similar in" +"shape and size? Is there any relation between" +"} premolars (2)" +"shape and function of the teeth? Dental formula" +"" +"" +"" +"" +"AN" +"}" +"" +"canine (1)" +"inscisors (2)" +"explains the arrangement of teeth. On the basis" +"of the figure try to guess what could be the the" +"function of molars? You had studied in earlier" +"classes inscisors have sharp edges, canines have" +"" +"" +"" +"" +"NG" +"fig-3: Dentition" +"sharp and pointed edges while molars and" +"premolars have blunt and nearly flat surface." +"What do you think could be the function of inscisors?" +"Which set of teeth help in grinding food?" +"Which set helps in tearing food?" +"LA" +"Write your dental formula?" +"Now fill up the following table with proper information based on the" +"figure given here." +"TE" +"" +"Table-2" +"Number of teeth" +"Type of teeth in each jaw Shape Function" +"T" +"ER" +"" +"" +"" +"" +"The circular muscles of the mouth enable the food to be pushed into" +"the oral cavity and to be moved around. As the food cannot be swallowed" +"directly the teeth grind, chew and shred it. This process is called" +"mastication. For this purpose the surface muscles of the jaw help in biting" +"and chewing actions, and move the jaw up, down, forward and backward" +"SC" +"" +"" +"" +"" +"during food mastication. You may have observed your lower jaw moving" +"up and down as you chew food. The teeth help in cutting and grinding while" +"tongue movements evenly spread out the food and help in mixing it with" +"saliva. The muscles of the mouth enable the food to be pushed in the oral" +"cavity and to be moved around. The fifth cranial nerve has been found to" +"control the movement of muscles in the jaw." +"" +"150 X Class Coordination in life processess" +" Does the level of saliva secretion increase due to presence of food" +"in the mouth?" +"" +"" +"" +"" +"A" +"Can the process of chewing go on in the absence of saliva?" +"Does the saliva have any other roles to play?" +"" +"" +"" +"" +"AN" +"Let us find out the role of saliva." +"Activity-7" +"Action of saliva on flour (ata)" +"Take a test tube half filled with water and add a pinch of flour to it." +"" +"" +"" +"" +"NG" +"Shake the test tube well till the flour gets mixed. Take a few drops of this" +"in a watch glass and test for the presence of starch by putting a drop of" +"diluted tincture iodine in it. A blue black color confirms the presence of" +"starch." +"Now divide the mixture into two equal halves by transferring it to" +"LA" +"another test tube. Note that both the test tubes have the same amount of" +"solution. Add a teaspoon of saliva to one of the test tube and mark it. Do" +"not add anything in the other test tube. After some time (45minutes) add a" +"drop of dilute Tincture Iodine solution to test tubes containing the solution." +"TE" +"" +"Do you observe any change in the solutions? Why does the change occur?" +"Do you think the same process goes on in the mouth when food is taken?" +"Under the action of autonomous nervous system saliva is secreted by" +"three pairs of the salivary glands to moisten the food to make chewing and" +"swallowing easier. As a result of chewing, food forms into a slurry mass" +"T" +"" +"" +"called ‘bolus’ that is transported into the oesophagus by the action of" +"swallowing with the help of the tongue." +"ER" +"" +"" +"" +"" +"The enzyme salivary amylase in the saliva breaks down the large starch" +"molecule into smaller subunits usually into sugars. The mechanism for" +"swallowing is also under nervous coordination and its control center is" +"somewhere in the brain stem (medulla oblongata and others). During" +"mastication food size becomes convenient to swallow." +"SC" +"" +"" +"" +"" +"What is the use of such an increase in surface area of food?" +"What about the nature of medium for salivary amylase to act on" +"food component?" +"If we swallow food material directly without mastication what will happen?" +"Do you think the pH of our mouth changes?" +"" +"Free distribution by T.S. Government 2019-20 151" +" Activity-8" +"Testing pH of mouth at intervals of one hour." +"" +"" +"" +"" +"A" +"Ask your chemistry teacher to give you a strip of pH paper with a" +"colour chart. (see the fig.4)" +"" +"" +"" +"" +"AN" +"You can do this in your school by taking a small piece of the pH paper" +"and touching it to your tongue. Match the colour with the colour chart and" +"note the pH first. See to it that you are able to take some readings after" +"having your food at lunch break. Compare your readings with that of your" +"friend. Take at least 4 readings. You have to prepare your own table to" +"" +"" +"" +"" +"NG" +"record your observations." +"What is the usual range of pH of your mouth? Acidic or basic?" +"Did you observe any change in pH after eating? What may have" +"caused the change?" +"LA" +"In what kind of pH do you think salivary amylase acts well?" +"Does the type of food have any role to play on the pH of our mouth?" +"Test with different types of food as you eat them and check just after" +"you have swallowed them." +"TE" +"" +"Do not hurry to complete the table. Take your own time." +"(pH beyond 7 is alkaline, pH- below 7 is acidic, pH 7 is neutral)." +"Based on the above tests we know that the saliva secreted causes the" +"medium to change to alkaline as it aids in action of enzyme, salivary" +"fig-4: pH amylase." +"scale" +"T" +"" +"" +"" +"Do you know?" +"ER" +"" +"" +"" +"" +"Why do we salivate during a nap of daytime?" +"You have heard about Nocturnal animals, which are active during nights, but we" +"are active during daytime and take rest at night. All the systems of our body are active" +"in function during the time of our activity. Hence, man is a diurnal animal. Our" +"SC" +"" +"" +"" +"" +"digestive system is also active and ready to receive the food for digestion. If we" +"sleep during daytime saliva oozes out of our mouth and wets the pillows. This will" +"not happen during night time. We secrete 1-1.5 liters of saliva per day." +"" +"What are the different systems that contribute to the proper" +"functioning of digestion in the mouth?" +"After the digestive process in the mouth where does the food move to?" +"" +"152 X Class Coordination in life processess" +" Travel of food through oesophagus" +"The oesophagus receives the food pushed by the swallowing action of" +"the mouth." +"" +"" +"" +"" +"A" +"What are the systems that come into play for swallowing food?" +"" +"" +"" +"" +"AN" +"The following schematic representation shows some functional and" +"stuctural attributes of oesophagus. Observe it and answer the following" +"questions." +"" +"Walls secrete mucus passes food to stomach" +"slimmy substance by wave like movement of" +"" +"" +"" +"" +"NG" +"walls (peristalsis)" +"" +"Long tube upper end" +"Oesophagus muscular and elastic" +"connects to pharynx LA walls carry on wave like" +"lower end connects to the movement by contraction" +"stomach and relaxation" +"" +"What does the schematic diagram tell us about the oesophagus?" +"TE" +"" +"What kind of the tube is oesophagus?" +"How does mucus help in passage of food?" +"" +"Activity-99" +"Activity" +"Making a model of oesophagus to observe how bolus moves" +"T" +"" +"" +"" +"forward" +"Take a piece of waste cycle tube. Lubricate the inner side of the tube" +"ER" +"" +"" +"" +"" +"with oil. Insert one or two oil coated potatoes in the tube. Now try to push" +"the potatos by squeezing the tube." +"How do you squeeze the tube to make the potatoes pass through?" +"How did the oil work?" +"SC" +"" +"" +"" +"" +"Do you think that the muscles in the wall of the oesophagus have to" +"do something like this?" +"fig-5: Potato in" +"How did oil help you in pushing the potatoes through the pipe?" +"cycle tube" +"Peristaltic movement in oesophagus" +"Look at the fig-6, which shows wave like movement of wall of" +"oesophagus and observe the position of the food bolus." +"Free distribution by T.S. Government 2019-20 153" +" How did the position of the bolus change?" +"What is the similarity of movement of food" +"" +"" +"" +"" +"A" +"epiglottis illustrated in the diagram and the activity" +"oesophageal sphincter performed by you?" +"contracted" +"The walls of the food pipe secrete a slippery" +"" +"" +"" +"" +"AN" +"relaxed muscles" +"contracted muscles substance called mucus. Mucus lubricates and" +"bolus protects the oesophageal walls from damage. This" +"sphincter relaxed helps the food bolus to slide down easily just as" +"the oiled potatoes that move in the tube. Besides" +"this, the saliva in the bolus also aids in easy" +"" +"" +"" +"" +"NG" +"stomach" +"movement of food, which moves into the stomach." +"The wall of the oesophagus is made up of two" +"fig-6: Peristaltic movement of bolus" +"kinds of smooth muscles. The inner layer consists" +"of circular muscles and the outer layer of longitudinal muscles. Contraction" +"of the circular muscles results in narrowing of the oesophagus just behind" +"LA" +"the bolus. So the food is squeezed downwards. Contraction of the" +"longitudinal muscles infront of the bolus widen the tube, this results in" +"shortening of that particular part of the oesophagus. Contraction and" +"relaxation of these muscles bring in a wave like motion that propels the" +"TE" +"" +"food bolus into the stomach by the action called as “peristalsis” (you have" +"studied about this in the chapter on nutrition). This is involuntary and under" +"the control of autonomous nervous system." +"What makes the movement of the food bolus in the oesophagus easy?" +"Think why people are advised not to swallow food without chewing" +"T" +"" +"" +"properly or do not eat in hurry." +"Stomach the mixer and digester" +"ER" +"" +"" +"" +"" +"Why do you think the stomach is structured like a bag rather than" +"a tube like oesophagus?" +"What sets such processes into action?" +"When the food is in the oral cavity, the nerves in the cheek and" +"SC" +"" +"" +"" +"" +"tongue are stimulated. These carry messages in the form of nerve impulses" +"to the brain. Brain analyses the message. These messages are transmitted" +"from the brain through motor nerve to the wall of the stomach, and" +"stimulate the gastric glands to produce gastric juice." +"The walls of stomach secrete juice containing hydrochloric acid" +"(HCl) Most of us may have experienced belching and the burning sensation" +"after vomiting. What do you think may have caused the burning sensation?" +"154 X Class Coordination in life processess" +" These secretions are stimulated by the nervous system. The contraction" +"of the stomach muscles squeeze and mix the food with the acids and" +"juices of the stomach. These digestive juices turns the food into a" +"" +"" +"" +"" +"A" +"smooth porridge like consistency called chyme. Some large protein" +"molecules are also broken down here in to simple molecules." +"" +"" +"" +"" +"AN" +"What stimulates stomach muscle into action?" +"What causes the stomach to churn and mix the food?" +"As the process of digestion in the stomach nears completion, the" +"contractions of the stomach decrease. What would be the reason? Which" +"substance present in blood regulates contraction of stomach? This prompts" +"" +"" +"" +"" +"NG" +"the muscles, called as pyloric sphincter at the opening of the stomach and" +"the first part of the small intestine or duodenum, to relax. This opens the" +"pathway into duodenum releasing the partially digested food (chyme) in" +"small quantities into the duodenum." +"Why should only a small quantity of food be passed from stomach" +"to duodenum?" +"LA" +"pyloric valve" +"pyloric valve pyloric valve" +"slightly opened." +"closed closed" +"TE" +"" +"Propulsion: Peristaltic Grinding: The most vigorous Retropulsion: Small amounts of chyme is" +"waves move food from peristalsis and mixing action pushed into the duodenum, simultaneously" +"one part to the other. occur close to the pylorus. forcing most of it back into the stomach." +"fig-7: Peristaltic movement in stomach" +"T" +"" +"" +"Peristalsis in Stomach" +"Peristalsis involves the contraction of the muscle behind the food and" +"the relaxation of the muscle in front of the food giving rise to a thrust that" +"ER" +"" +"" +"" +"" +"pushes the food forward through the digestive canal. A wave of contraction" +"followed by relaxation in muscles helps in forward movement of food." +"What is involved in bringing about peristalsis?" +"What is the direction of peristalsis (which end of the gut does it begin)?" +"What happens if the direction of peristalsis is reversed?" +"SC" +"" +"" +"" +"" +"You might have observed during peristalsis digested food is in the" +"form of chyme gets reversed back in the oesophagus. Identify for" +"the reverse peristalsis in fig.7." +"Have you observed a ruminating cow/ buffalo under a tree or somewhere" +"else? Carefully observe its neck and throat. Do you see something moving" +"from its throat to mouth? After that, the cow or buffalo starts chewing. It is" +"the bolus moving from a part near the stomach of the animal to its mouth. It" +"is reverse peristalsis. Though it is a common process in ruminants such" +"Free distribution by T.S. Government 2019-20 155" +" as the cow, buffalo etc. that have an extra pouch in the stomach to store" +"quickly swallowed food, in human beings it is mainly a protective mechanism" +"to expell unwanted substances from the food canal." +"" +"" +"" +"" +"A" +"We observe that digestion of food starts from the mouth. While the" +"food passes through the gut the food settles for some time for digestion" +"" +"" +"" +"" +"AN" +"at certain locations. So food does not move uniformly through the digestive" +"system. Let us observe the time period." +"Table-3" +"Percentage Emptying of stomach Emptying of small intestine" +"" +"" +"" +"" +"NG" +"1 2½ hours" +"50% 2 to 3 hours" +"2" +"Total 100% 4 to 5 hours 30 to 40 hours" +"(Transit through colon)" +"" +"(These are only averages. The movement of materials varies among" +"LA" +"individuals and time after different meals.)" +"Our stomach is not like a bag with specific volume. It is like a pouch" +"which is elastic in nature. the size of the stomach increases based on the" +"food that we intake. Digestive juices are produced depending on the" +"TE" +"" +"quantity of food material. If the stomach would produce same amount of" +"digestive juices irrespective of the food quantity the walls of stomach" +"would be destroyed. ( See annexure )" +"We also know that stomach secretes strong acids during digestion." +"The HCl secreted by the walls of the stomach is strong enough to digest" +"the hard bones as well..Then how is the stomach protected from the" +"T" +"" +"" +"" +"secretions of its own acids. To understand this we will perform the" +"following experiment." +"ER" +"" +"" +"" +"" +"Lab Activity" +"Take two similar green leaves. Apply vaseline or petroleum jelly or" +"grease on one leaf leave the other free. Add 1 or 2 drops of some weak" +"SC" +"" +"" +"" +"" +"acid on both the leaves .Observe them after half an hour or so and write" +"your observation in your note book." +"Which leaf was affected by the acid?" +"What kind of change did you observe in the leaves?" +"What saved the other leaf from the effect of acid?" +"Mucus secreted by some cells present in the walls of the stomach" +"156 X Class Coordination in life processess" +" form a thin lining on the walls of the stomach. This counters the action" +"of acid. The function of petroleum jelly can be compared to that of" +"mucus lining the stomach walls. Hence the stomach is protected from" +"" +"" +"" +"" +"A" +"damage being caused by the secretion of its own acids." +"Travel of food from the stomach to the intestine" +"" +"" +"" +"" +"AN" +"Now food is a soup like mixture when it leaves the stomach and" +"enters the small intestine. When the food enters the intestine the acidic" +"nature of the chyme initiates the production of hormones like secretin" +"and cholecystokinin which stimulate pancreas, liver and walls of small" +"intestine to secrete pancreatic juice, bile juice and succus entericus.The" +"" +"" +"" +"" +"NG" +"absorption of nutrients by villi in the small intestine is a very selective" +"process. The walls of the intestine allows only tiny nutrient particles to" +"pass through.(Refer Movement of substances through plasma membrane" +"in class IX)" +"Why do you think small intestine is long and coiled?" +"LA" +"What process is involved in this process of absorption?" +"" +"Activity-10" +"Paper tube and folded papers" +"Take 10 20cm size chart paper fold the chart paper and join both" +"TE" +"" +"ends with gum to make a tube. Now take 20 20cm chart paper and make" +"a tube as mentioned the same above try to insert the big tube in small one." +"Can you? It is not possible. Now take another 20 20cm chart paper fold" +"the paper as many folds as possible. Now join both ends to make a folded" +"paper tube. Try to insert folded tube in first tube. Can you? How is it fig-8:" +"T" +"" +"" +"possible? Paper tube" +"Compare the area of the folded papers with that of" +"ER" +"" +"" +"" +"" +"the roll. Do you find any increase in the area ?If so epithelium" +"try to find out the reasons?" +"The inner surface of the small intestine contains network of blood" +"capillaries" +"thousands of finger like projections called villi." +"What is the relation between finger like structures mucus membrane" +"SC" +"" +"" +"" +"" +"and paper folds mucus glands" +"" +"These villi increase the surface area so that the food lacteal (part of" +"lymphatic system)" +"retained in the folds can remain longer thereby enhancing" +"absorption." +"fig-9: Schematic" +"What systems do you think are working together here?" +"diagram of a villus" +"Do you think those systems work together in the whole" +"length of the digestive canal? Why/ Why not?" +"Free distribution by T.S. Government 2019-20 157" +" The digestive tract is unique among internal organs because it is" +"exposed to a large variety of physiochemical stimuli from the external" +"world in the form of ingested food. As a consequence, the intestine has" +"" +"" +"" +"" +"A" +"developed a rich store of co ordinated movements of its muscular apparatus" +"along with neural apparatus to ensure the appropriate mixing and propulsion" +"" +"" +"" +"" +"AN" +"of contents during digestion, absorption, and excretion." +"The neural apparatus of our digestive tract comprises of such a vast" +"and complicated network of neurons that it has been nicknamed by scientists" +"as the second brain!" +"Research in this area is currently investigating how the second brain" +"" +"" +"" +"" +"NG" +"mediates the body’s immune response; after all, at least 70 percent of our" +"immune system is aimed at the gut to expel and kill foreign invaders." +"Scientists are also working to find out how trillions of bacteria in the" +"gut ‘communicate’ with the cells of gut nervous system." +"A deeper understanding of this mass of neural tissue, filled with" +"LA" +"important neurotransmitters, is revealing that it does much more than" +"merely handle digestion or inflict the occasional nervous pang of hunger." +"The little brain in our inner yards, in connection with the big one in our" +"skull, partly determines our mental state and plays key roles in certain" +"TE" +"" +"diseases throughout the body." +"Often you may have experienced that if you have tension for some" +"reason you start having loose motions. What does this show us?" +"Although its influence is far-reaching, the second brain is not the seat" +"of any conscious thoughts or decision-making. Technically known as the" +"T" +"" +"" +"enteric nervous system, the second brain consists of sheaths of neurons" +"embedded in the walls of the long tube of our gut, or alimentary canal," +"which measures about nine meters end to end from the oesophagus to the" +"ER" +"" +"" +"" +"" +"anus. The second brain contains some 100 million neurons, more than in" +"either the spinal cord or the peripheral nervous system. This multitude of" +"neurons in the enteric nervous system enables us to “feel” the inner world" +"of our gut and its contents. Stimulating and coordinating the breaking down" +"of food, absorbing nutrients, and expelling of waste requires chemical" +"SC" +"" +"" +"" +"" +"processing, mechanical mixing and rhythmic muscle contractions that" +"move everything down the line." +"Thus equipped with its own reflexes and senses, the second brain can" +"control several gut functions often independently of the brain. Several" +"scientists also believe that the system is a way too complicated to have" +"evolved only to make sure things move through and out of our gut smoothly." +"" +"158 X Class Coordination in life processess" +" Explusion of wastes via blood through" +"the kidneys, skin etc., are mainly salts," +"" +"" +"" +"" +"A" +"water and urea." +"Expulsion of wastes" +"" +"" +"" +"" +"AN" +"Undigested food matter is expelled in" +"the form of stool." +"" +"What moves out of the gut?" +"Two major pathways of waste expulsion are shown above. Which" +"" +"" +"" +"" +"NG" +"of the two do you think happens exclusively through the gut?" +"Imagine you made a roll by wrapping a hand full of left over tea" +"leaves in a tissue paper. Later you press the roll gently and open it. What" +"did you observe? You find the tissue paper had absorbed the water from" +"the tea leaves." +"LA" +"Similarly when the unwanted waste material (stools / faeces) reach the" +"large intestine. The peristaltic waves move the stool into the rectum. The" +"left side of the colon acts like a storage tank of faeces. Water gets reabsorbed" +"and the remaining wastes usually hard mass gets stored in the last part" +"TE" +"" +"(Rectum) of the large intestine. This smelly yellowish faecal matter usually" +"called as stool is later expelled out of the body through the anus." +"What controls the exit of stools from the body?" +"Do you think the control is voluntary? Why / rectum" +"why not?" +"T" +"" +"" +"There are two muscular layers helping the exit internal anal" +"of stool. Inner internal anal sphincter works as sphincter" +"ER" +"" +"" +"" +"" +"involuntary and other external anal sphincter works anus" +"" +"as voluntary control. These muscular structures external" +"anal" +"help in opening and closing of the aperture of the sphincter" +"canal which are called as anal sphincter. fig-10: Anal sphincter" +"" +"Did we have a sphincter in any other part of the digestive cannal?" +"SC" +"" +"" +"" +"" +"Where was it?" +"Suppose a person has consumed more fluids than what the body actually" +"need. How do think the extra fluid will be removed from the body?" +"We have so far seen how several systems work together to bring about" +"the process of digestion. Where does this process draw energy from to" +"run smoothly?" +"" +"Free distribution by T.S. Government 2019-20 159" +" What is the fate of the digested substances that move into blood" +"from the intestine?" +"If energy has to be obtained from food it has to be oxidised. For this" +"" +"" +"" +"" +"A" +"purpose respiration has to go on. During inhalation oxygen moves across" +"the walls of the alveoli and enters the blood. From here it enters the red" +"" +"" +"" +"" +"AN" +"blood cells and gets distributed throughout the cells of our body. At the" +"same time carbon dioxide from the blood moves into the alveoli of the" +"lungs and breathed out during exhalation. Nutrients in the cells get oxidized" +"and energy is released." +"Where is the energy stored?" +"" +"" +"" +"" +"NG" +"Which system do you think will remove the excess salts from our" +"body?" +"What would be the path of salt removal from gut to the out side of" +"our body?" +"LA" +"During respiration we breathe continuously by inhaling and exhaling" +"air. This is an involuntary process controlled by the medulla oblongata of" +"the autonomous nervous system (ANS). During respiration the movement" +"of inter costal muscles diaphragm moves the ribs cage inflating and deflating" +"TE" +"" +"the lungs. Air containing more of oxygen enters the blood stream through" +"lungs. If the oxygen has to reach the tissues it has to be circulated through" +"blood. How does this process go on?" +"Hence the process of digestion which is a complex process that" +"involves many organs and organ systems. Though digestion occurs in the" +"food canal, co-ordination of respiration and blood circulation is necessary" +"T" +"" +"" +"" +"otherwise oxidation of food and transport of substances which is vital for" +"energy releasing process will not take place. This may lead to the shut" +"ER" +"" +"" +"" +"" +"down of systems interdependent on each other." +"" +"Key words" +"Ghrelin, Leptin, Taste receptor, Chemoreceptors, Papillae, Food bolus, Peristalsis," +"SC" +"" +"" +"" +"" +"Chyme, Pyloric Sphincter, Villi, Medulla oblongata , Brain stem, Nervous system." +"" +"" +"What we have learnt" +"" +"The food taken by us has to be broken down into constituent substances for proper digestion," +"assimilation and energy releasing processes." +"" +"160 X Class Coordination in life processess" +" The human digestive system involves both the muscular and nervous systems." +"A special nervous system that exists in the gut consist of nearly 100 million nerves that coordinates" +"the muscular activity ,blood flow,digestion and absorption of nutrients and other activities of the" +"" +"" +"" +"" +"A" +"food canal (gastro intestinal tract)." +"The hormone Ghrelin secreted in the stomach is responsible for hunger generating sensations." +"Another hormone leptin that gets secreted suppresses hunger." +"" +"" +"" +"" +"AN" +"Taste can be identified easily only when the tongue is pressed against the palate." +"Taste and smell are closely related. The chemoreceptors present in the nose and the tongue trigger" +"signals in the form of nerve impulses to the brain where the smell and taste is detected." +"The saliva secreted maintains an alkaline medium that aids in digestion of starch. Our mouth secretes" +"acid as well ,this gives protection to our mouth from harmful bacteria etc., Under the action of" +"" +"" +"" +"" +"NG" +"autonomous nervous system Saliva released by the salivary glands moistens the food to make" +"chewing and swallowing easier." +"The muscular and sensory organ in the oral cavity is the tongue which is not only gustatory in" +"function but also performs different functions including, shifting and mixing the food in the oral" +"cavity and swallowing." +"The mechanism for swallowing is coordinated by the swallowing centre in the brain stem." +"LA" +"Contraction and relaxation of the muscles in the gut brings in a wave like motion that propels the" +"food forward and is called peristalsis. This is a muscular wave that travels the entire length of the" +"food canal. This is involuntary and under the control of autonomous nervous system as well as gut" +"nervous system." +"The muscular contractions of the stomach churns the food into a semiliquid substance known as" +"TE" +"" +"chyme. Entry of chyme into the duodenum is regulated by a muscle called as the pyloric sphincter." +"The strong acid (HCl) renders the pH in stomach acidic causing the protein digesting enzymes to" +"swing into function." +"Juices secreted in the stomach breaks down the food into a smooth mixture called chyme." +"The mucus lining of the stomach protects it from damage by its own acids." +"The coordination among the processes of digestion, respiration and circulation is necessary for" +"T" +"" +"" +"" +"utilization and oxidation of food and transport of the nutrients. Muscular and nervous control helps" +"to carry out the processes in a regulated manner." +"ER" +"" +"" +"" +"" +"Improve your learning" +"1. What do you mean by hungerpangs?(AS1)" +"2. What are the organ systems involved in digestion of food which we eat?(AS1)" +"3. Rafi said smell also increase our appetite can you support this statement. how?(AS1)" +"SC" +"" +"" +"" +"" +"4. Write a note on peristalsis and sphincter function in stomach.(AS1)" +"5. Observe the given part of the digestive system. What is it? What is it’s role during digestion?(AS1)" +"6. Give reasons.(AS1)" +"a) If we press tongue against the palate we can recognise taste easily." +"b) We can’t identify taste when food is very hot." +"c) If glucose level falls in blood we feel hungry." +"d) Small intestine is similar to a coiled pipe. Q.No: 5" +"" +"Free distribution by T.S. Government 2019-20 161" +" e) Urination increases when we take lot of fluids" +"f) The process of digestion goes on in a person whose central nervous system has been largerly" +"affected" +"" +"" +"" +"" +"A" +"7. Write difference between the following.(AS1)" +"a) bolus - chyme b) small intestine - large intestine" +"" +"" +"" +"" +"AN" +"c) mastication - rumination d) propulsion - retropulsion" +"8. How can you say that mouth is a munching machine?(AS1)" +"9. What is mastication? Explain the role of different sets of teeth in this process.(AS1)" +"10. During the journey of food from mouth to stomach through oesophagus. How does muscular" +"system coordinate in this process?(AS1)" +"11. Is there any reason for the intestine to be coiled with many folds.In what way it is helpful during the" +"" +"" +"" +"" +"NG" +"process of digestion?(AS1)" +"12. What is the function of peristalsis in these parts?(AS1)" +"a) oesophagus b) stomach c) small intestine d) large intestine" +"13. How can you justify the enteric nervous system as the second brain of the gut?(AS1)" +"14. Rajesh feels hungry upon seeing food.Sheela says no to food as she is not hungry.What makes" +"LA" +"Rajesh hungry and what suppresses Sheelas hunger?(AS1)" +"15. How are taste and smell related?(AS1)" +"16. List out the sphincter muscles of the food canal you have observed and give a brief description?(AS1)" +"17. What experiment should you perform to understand action of saliva on flour? Explain it’s procedure" +"and apparatus that you followed.(AS3)" +"TE" +"" +"18. What happens if salivary ducts are closed?(AS2)" +"19. If size and shape of small intestine is like oesophagus what will happen?(AS2)" +"20. Prepare a questionnaire to understand nervous coordination in digestion process.(AS2)" +"21. Suggest a simple experiment to prove the role of palate in recognizing taste.(AS3)" +"22. Collect information related to feeling hunger from your school library and prepare a note on it.(AS4)" +"23. Draw the block diagram showing sensation of taste from food material to brain.(AS5)" +"T" +"" +"" +"" +"24. Draw a neatly labled diagram showing a peristaltic movement in oesophagus. Explain the importance" +"of mucus on the walls of food pipe.(AS5)" +"ER" +"" +"" +"" +"" +"25. Draw a schematic diagram of villus in small intestine. Explain how digestive system coordinate with" +"circulatory system.(AS5)" +"26. The mere smell or sight of food stimulates hunger .Describe the process through a neat diagram?(AS5)" +"27. With the help of a diagram show the movement of food from mouth to the stomach.What muscles" +"and nerves are involved in the movement of food and what is this action called as?(AS5)" +"SC" +"" +"" +"" +"" +"28. Prepare a cartoon on Pavlov’s experiment with a suitable caption.(AS6)" +"29. How do you appreciate stomach as a churning machine .How does this coordination go on?(AS6)" +"30. There is a great variety in diversified life processes, express your feelings in the form of a poem.(AS7)" +"31. Suggest any two important habitual actions to your friend while eating food, keeping in view of this" +"chapter.(AS7)" +"" +"" +"" +"" +"162 X Class Coordination in life processess" +" Fill in the blanks" +"" +"" +"" +"" +"A" +"1. 2 : 1 : 2 : 3 is the ratio of our dentition. Here 1 represents ____________" +"2. Large protein molecules are broken down in _________ of digestive track." +"" +"" +"" +"" +"AN" +"3. __________ is the strong acid which is secreated during digestion." +"4. Olfactory receptors present in ___________ trigger signals to brain." +"5. pH of saliva is _________ in nature." +"6. Fill in the blanks with suitable words given below." +"Fluctuation s of hormone (i)_____________ levels results in sensation of hunger and motivation of" +"" +"" +"" +"" +"NG" +"consuming food. When you feel your stomach is full and there is no need of food any more." +"Another hormone (ii)_____________ that gets secreted suppresses hunger. When we take food" +"into the mouth it has to be chewed thoroughly. For this purpose the (iii)_____________ muscles" +"help in chewing actions, while the (iv)_____________ muscles of the jaw moves the jaw up," +"down, forward and backward during food mastication. The (v)_____________ nerve controls" +"the muscles of the jaw. Under the action of (vi)_____________ nervous system Saliva is released" +"LA" +"by the salivary glands moistens the food to make chewing and swallowing easier. The salivary" +"(vii)_____________ in the saliva breaks down the starch into sugars. As a result of chewing the" +"food is transported into the oesophagus by the action of swallowing which is coordinated by the" +"swallowing centre in the (viii)_____________ and the (ix)_____________. The tongue which is" +"gustatory recognizes the taste and (x)_____________ nerve plays an important role in sensation" +"TE" +"" +"of taste." +"Choose the right ones." +"(i) leptin, ghrelin gastrin secretin." +"(ii) ghrelin leptin secretin gastrin." +"(iii) deep muscles ,surface muscles ,circular muscles, striated muscles." +"ace muscles, deep muscles, neck muscles, long muscle." +"(iv)surface" +"T" +"" +"" +"(v) fifth cranial nerve ,second cranial nerve,fifth facial nerve, spinal nerve." +"central nervous system, peripheral nervous system autonomous nervous system." +"(vi)central" +"ER" +"" +"" +"" +"" +"(vii) lipase, sucrase, galactase,amylase." +"(viii) medulla oblongata, cerebrum , 8th spinal nerve,cranial nerve.7th cranial nerve." +"(ix)Pons" +"(ix) Pons varolii, brain stem ,medulla oblongata, mid brain." +"(x) 6th cranial nerve, 5th cranial nerve, 10th cranial nerve, optic nerve." +"" +"Choose the correct answer" +"SC" +"" +"" +"" +"" +"7. In which of the following situations you can taste quickly. ( )" +"A) Put sugar crystals on tongue B) Put sugar solution on tongue." +"C) Press the tongue slowly against the palate D) Swallow directly without grinding and shreding" +"8. Peristalsis is because of ( )" +"A) Contraction of longitudinal muscles. B) Contraction of circular muscles" +"C) Under control of autonomous nervous system D) Digestive secretions." +"Free distribution by T.S. Government 2019-20 163" +" 9. Sphincter that helps in opening of stomach into duodenum (" +")" +"A) Cardiac B) Pyloric C) Anal D) Gastric" +"" +"" +"" +"" +"A" +"10. Glucose and amino acids are absorbed through the following part of villus. (" +")" +"" +"" +"" +"" +"AN" +"A) epithelial cells B) blood capillary C) lymphatic vessel D) all" +"11. The region in brain portion that controls hunger signals ( )" +"A) medulla B) diencephalon C) cerebrum D) mid brain" +"12. Human organism is an internal combustion machine because of ( )" +"A) assimillation of energy from food B) liberate CO2 during respiration" +"C) expel waste food at the end state digestion D) secrete powerful digestive juices" +"" +"" +"" +"" +"NG" +"Annexure" +"" +"Historical evidence of human digestion that led to discovery of other truths" +"The man with a window in his stomach." +"One fine morning at Fort Mackinac on the upper Michigan peninsula a 19 year Voyageur" +"LA" +"Alex St.Martin had a gun wound in his stomach that was fired accidentally. The wound" +"perforated the abdominal wall and stomach with profuse bleeding. Dr.Beaumont the army" +"surgeon was called on to attend the wounded man. Dr. Beaumont cleaned the wound and" +"pushed the protruding portions of lungs and stomach back into the cavity and dressed the" +"TE" +"" +"wound." +"Dr. Beaumont was surprised to see St. Martin alive the next day as he never expected" +"so. With his medical expertise Dr. Beaumont treated the wound and did his best to extend" +"his life. When the wound got healed completely, the stomach had fused with the body wall" +"leaving a hole. Part of the wound formed a small flap that resembled a natural valve. This" +"allowed Dr.Beaumont to draw out fluids from Martin’s stomach for testing." +"T" +"" +"" +"" +"Dr.Beaumont turned St.Martin to the left side depressing the flap he inserted a 5-6" +"inch tube into the stomach gathered gastric juice had its components identified. He introduced" +"ER" +"" +"" +"" +"" +"food through the hole of the stomach with a string attached to it so that he could retrieve" +"the partially digested food for further examination. He conducted many experiments on" +"food digestion to know the function of stomach which had not been done before. He" +"discovered many things that were new to science." +"SC" +"" +"" +"" +"" +"For centuries stomach was thought to cook food by producing heat. Also theStomach" +"was viewed as a mill,a fermenting vat or a stew pan. Through his experiments Dr.Beaumonts" +"experiments revolutioned the concepts of digestion. June -on16,1822 became the beginning" +"for the the most pioneering experiments in medicine. He recounted many of his" +"observations and experiments in his journal which says “I consider myself but a humble" +"experimentor “ in which the information provided still obeyed scientific method basing all" +"the inferences on direct experimentation." +"" +"164 X Class Coordination in life processess" +" Some of the discoveries of Dr.Beaumont were." +"1) He measured the temperature of the stomach during digestion .To his surprise he found" +"there was no change or alteration in temperature. He found the temperature being" +"" +"" +"" +"" +"A" +"maintained constant ( 100F/38C )." +"2) He found out that pure gastric juice contains large amounts of HCl ,contrary to the" +"" +"" +"" +"" +"AN" +"previous opinions that gastric was nothing but contains simply water. As suggested by" +"some authors as the most general solvent in nature and of the alimentary canal. Even" +"the hardest bone cannot with stand its action .Even outside the stomach its capable of" +"effecting digestion. Based on the evidences he concluded that HCl as chemical agent" +"that aids in chemical reaction." +"" +"" +"" +"" +"NG" +"3) He found Gastric juice is not stored in the stomach. But ,is secreted when the food is" +"taken. When the food enters the stomach it excites the vessels to discharge its contents" +"immediately for digestion." +"4) He understood that digestion begins immediately when the food enters the stomach." +"He tested the contents of the stomach exactly 20mts after taking food (dinner containing" +"LA" +"ordinary food of boiled and salted beef, potatoes ,bread, beef and turnips) by collecting" +"the fluids from the flap and found digestion had commenced and was progressing well" +"at that time." +"5) He also discovered that food in the stomach satisfies hunger even though its not eaten." +"(food reaching the stomach without passing the mouth and oesophagus). To confirm" +"TE" +"" +"his assumptions he made St. Martin fast from breakfast time till 4’0 Clock and then" +"introduced food into the stomach through the flap. The sensation of hunger subsided." +"Though it was fortuitous experiments in medicine connected to digestion raised many" +"questions." +"What is the cause of hunger?" +"T" +"" +"" +"How does the brain know the happenings of the stomach?" +"What causes the gastric juices to secrete?" +"ER" +"" +"" +"" +"" +"How and what makes the food to be mixed with the digestive juices?" +"Does the process of digestion occur independently or involves other systems like" +"nervous and muscular as well ?" +"Vomiting - Belching" +"When we eat food substances -spoiled or not fit for our body-our digestive" +"SC" +"" +"" +"" +"" +"mechanism recognises it and reject to digest. Consequently some disturbance is" +"caused in the walls of the stomach that works under control of involuntary nervous" +"system and it expels the chyme along with undigested food. We call it as vomiting.Some" +"times we suddenly belch. During belching some digestive juices move back into the" +"mouth through oesophagus. We feel burning sensation in throat and chest.This is" +"due to bakcward movement of acids from stmach.This kind of muscular contractions" +"are controlled by 10th cranial nerve under control of Autonomous nervous system." +"Free distribution by T.S. Government 2019-20 165" +" A" +"Chapter" +"" +"" +"" +"" +"AN" +"8" +"" +"" +"NG" +"Heredity - From parent to progeny" +"LA" +"When we observe our world and its myriad forms of life, we are struck" +"by two seemingly opposite observations, the fantastic variety of life and" +"the similarity between them. As we shall see, we would need to understand" +"these two characteristics of life in order to understand how life evolves." +"When we say that something evolves, we mean not only that it changes," +"TE" +"" +"but that there is also some component of direction in that change." +"But, how does evolution take place? Does it occur in a slow and steady" +"manner or in quick jumps? Is it just about change and producing something" +"new and different?" +"In the chapter on reproduction we had studied that reproductive" +"T" +"" +"" +"processes usually give rise to individuals that have some new characters" +"in spite of the similarity that they share with their parents. Often such new" +"ER" +"" +"" +"" +"" +"characters give rise to observable changes in life forms." +"How are new characters produced?" +"Are they inherited?" +"Do they have any role in the process of evolution?" +"In this chapter we shall try to explore several such questions." +"SC" +"" +"" +"" +"" +"New characters and variations" +"Think of your own family, what similarities do you share with your father" +"and your mother? Draw a table to represent the similarities of some" +"characters like colour of eye(cornea), colour of hair, type of hair, shape of" +"nose, shape of face, type of ear lobe(attached or free), inner thumb markings" +"etc. Write your characters and that of your parents in two separate columns." +"166 X Class Heredity - From parent to progeny" +" How many similar characteristics do you find among you and your" +"parents?" +"Is there any character in you that is neither like your father nor" +"" +"" +"" +"" +"A" +"like your mother? What are they?" +"Where do you think you got such a character from?" +"" +"" +"" +"" +"AN" +"Let us do an activity to find out more about this." +"Activity-1" +"Compare your traits with the traits of your parents, brother, sister and" +"grand parents by drawing a table as given below in your notebook." +"" +"" +"" +"" +"NG" +"Table-1" +"Characters In me In my Mother In my Father In my brother In my sister In my grandparents" +"" +"1. Curly hair" +"LA" +"Is there any character in you similar to that of your mother as well" +"as your grandma?" +"TE" +"" +"Is there any character in you similar only to that of your grandma?" +"How do you think these characters may have been inherited by you" +"from grandma?" +"Is there any character that is not present in grandma but present in" +"your mother and you?" +"T" +"" +"" +"Think where from your mother got that character?" +"Activity-2" +"Activity-" +"Activity-2" +"ER" +"" +"" +"" +"" +"Observe some of your friends and note their characters in the following" +"table. Fill in yours as well." +"Table-2" +"Name of Colour Ear lobes Marking on Length of Colour of Any other" +"SC" +"" +"" +"" +"" +"your friend of skin Free/ inner side of fore head eyes features" +"attached thumb (Cornea)" +"" +"" +"" +"" +"Free distribution by T.S. Government 2019-20 167" +" Compare your characters to that of any one of your friend. How" +"many characters did you find were similar among you and your" +"friend?" +"" +"" +"" +"" +"A" +"Do you share more similar characters with your parents or with" +"your friends?" +"" +"" +"" +"" +"AN" +"Do you think that your differences from parents are more or less" +"than differences from friends? Why /why not?" +"" +"" +"" +"" +"NG" +"fig-1: Variations in cornea colour and ear lobes" +"LA" +"Differences in characters within very closely related groups of" +"organisms are referred to as variations" +"variations.. Often a new character in a group" +"may lead to variations which also get inherited." +"Is variation all about apparent differences?" +"Is it about some subtle differences as well that we most often overlook?" +"TE" +"" +"(Remember looking for two similar neem /doob grass plants in the chapter" +"on diversity and classification in class IX)" +"Activity-3" +"Activity-" +"Activity-3" +"Observe seeds in a pea or bean pod. You may observe several parts to" +"T" +"" +"" +"arrive at a generalisation." +"Can you find two similar seeds there?" +"ER" +"" +"" +"" +"" +"What makes them vary? (Hint: You know that seeds are formed from" +"ovules)" +"Why variations are important? How are variations useful for an" +"organism or a population?" +"Over centuries variations and their role in nature have been studied by" +"SC" +"" +"" +"" +"" +"naturalists. During early 19th century, a lot of work was done by several" +"scientists. Some of these studies will help us to understand how variations" +"occur and are transferred from one generation to the next. We shall study" +"a detailed account of experimental evidences provided by Gregor Johann" +"Mendel in the early 19th century who is known as ‘Father of genetics’." +"In 1857 Gregor Johann Mendel started working on the problem of" +"how variations were passed from one generation to the other. Mendel did" +"168 X Class Heredity - From parent to progeny" +" not do his experimental work either in a University or in a Laboratory. As" +"he was a monk in a monastery he simply did his experiments in the" +"monastery garden. He worked for over seven years after which he presented" +"" +"" +"" +"" +"A" +"the conclusions from his experimental data in the form of a detailed" +"research paper." +"" +"" +"" +"" +"AN" +"Mendel made many careful observations of plants and found that" +"pea plants would be most suitable to carry on further experimentation." +"Then he planned and designed the experiments to find out the answers" +"to questions that came to his mind. He had worked on nearly 10,000" +"pea plants of 34 different varieties." +"" +"" +"" +"" +"NG" +"Observing pea plants carefully, Mendel noted that they differ" +"from one another in many ways. For example plants were tall or" +"fig-2: Gregor" +"dwarf, seed shape round or wrinkled, seed coat (cotyledon) colour" +"Johann Mendel" +"yellow or green. Thus, Mendel had chosen 7 pairs of contrasting characters" +"for his study as shown in the table-3." +"LA" +"Table - 3" +"Sl.No. Character Description" +"TE" +"" +"1. Colour of the flower Purple or white" +"2. Position of the flower Either in axial or terminal in position. (If they" +"are axial they are arranged in axial position" +"throughout the length of the stem)." +"T" +"" +"" +"3. Colour of the seed The seeds are either yellow or green colour." +"4. Shape of the seed The seeds are either round (smooth surface)" +"ER" +"" +"" +"" +"" +"or wrinkled." +"5. Shape of the pod The completely developed pod is either" +"smooth, full and constricted." +"6. Colour of the pod All the ripe pods are yellow in colour. Unripe" +"SC" +"" +"" +"" +"" +"parts are either yellow or green in colour." +"7. Length of the stem When the plants are grown in the same" +"environment some stems are tall (6 to 7 feet)" +"and some stems are dwarf (3/4 feet to 1½ feet)." +"" +"" +"" +"Free distribution by T.S. Government 2019-20 169" +" Table-3: The results of Mendel’s F1 crosses for seven characters in pea plants" +"" +"" +"" +"" +"A" +"Character Dominant Recessive F2 Generation Ratio" +"Trait Trait Dominant: Recessive" +"" +"" +"" +"" +"AN" +"Purple White" +"" +"" +"Flower colour 705:224 3.15:1" +"" +"" +"" +"" +"NG" +"Axial Terminal" +"" +"Flower" +"651:207 3.14:1" +"position" +"" +"" +"Yellow Green" +"LA" +"Seed colour 6022:2001 3.01:1" +"TE" +"" +"Round Wrinkled" +"" +"" +"Seed shape 5474:1850 2.96:1" +"" +"" +"" +"Inflated Constricted" +"T" +"" +"" +"" +"Pod shape 882:299 2.95:1" +"ER" +"" +"" +"" +"" +"Green Yellow" +"" +"" +"Pod colour 428:152 2.82:1" +"SC" +"" +"" +"" +"" +"Tall Dwarf" +"" +"" +"Stem length 787:277 2.84:1" +"" +"" +"" +"" +"170 X Class Heredity - From parent to progeny" +" Why Mendel had choosen garden pea as material for his experiments?" +"Because it has following advantages." +"1. Well defined characters 2. Bisexual flowers" +"" +"" +"" +"" +"A" +"3. Predominently self pollinating, 4. Suitable for cross pollination" +"5. It is an annual plant" +"" +"" +"" +"" +"AN" +"Do you know?" +"Pea is an annual plant, with a life cycle of one year. It is a cool season" +"crop grown in many parts of the world. Peas were present in Afghanistan" +"in 2000 BC, in Harappa, Pakistan, and in northwest India in 2250–" +"" +"" +"" +"" +"NG" +"1750 BC. In the second half of the 2nd millennium BC, this pulse" +"crop appeared in the Gangetic basin and southern India. Pea contains" +"vitamin ‘A, C, E, K & B’ and minerals like Ca, Fe, Mg, Mn, P, S & Zn." +"Mendel hypothesized that characters were carried as traits and an" +"organism always carried a pair of factors for a character. He also" +"hypothesized that distinguishing traits of the same character were present" +"LA" +"in the population of an organism. He assumed that the traits shown by the" +"pea plants must be in the seeds that produced them. The seeds must have" +"obtained these traits from the parent plants." +"How do parent plants pass on their traits to the seeds? Will the seeds" +"from tall plants always produce new tall plants?" +"TE" +"" +"Mendel carried out several experiments to find out answers to such" +"type of questions." +"" +"Do you know?" +"Examples of experiments performed by Mendel" +"The following section shows number of experiments performed, number of" +"T" +"" +"" +"fertilizations carried out and the number of plants involved in the study." +"1. 1st experiment 60 fertilizations on 15 plants." +"ER" +"" +"" +"" +"" +"2. 2nd experiment 58 fertilizations on 10 plants." +"3. 3rd experiment 35 fertilizations on 10 plants." +"4. 4th experiment 40 fertilizations on 10 plants." +"5. 5th experiment 23 fertilizations on 5 plants." +"6. 6th experiment 34 fertilizations on 10 plants." +"7. 7th experiment 37 fertilizations on 10 plants." +"SC" +"" +"" +"" +"" +"Mendel selected such kinds of plants that expresses a selected character over" +"several generations. Such plants according to him were pure breed for that character." +"Mendel did the experiment with two pure breeds of peas for seed colour contrasting" +"characters yellow and green, and they are represented as yellow with ‘Y’ and green" +"with ‘y’. He started cross fertilizing pure breeds having contrasting characters." +"Mendel started with two pure breeds of peas with different properties. We here" +"take as an example a characteristic colour of the pea seeds yellow and green." +"" +"" +"Free distribution by T.S. Government 2019-20 171" +" Cross pollinating a pure breed of yellow and green gave" +"Parents" +"First Filial (F1) generation (Mendel called it as first filial" +"" +"" +"" +"" +"A" +"or progeny of first generation parents. Filial means progeny.)" +"" +"" +"" +"" +"AN" +"F1 generation" +"All pea seeds were Yellow. These pea plants on self" +"pollination gave" +"" +"Second Filial (F2) generation Mendel self pollinated" +"these (F1) pea plants too, and found out that F2 generation had" +"" +"" +"" +"" +"NG" +"F2 generation [About 75% yellow (seeds) peas and about 25% green (seeds)" +"peas.]" +"" +"Third Filial (F3) generation By self pollination of" +"these (F2) pea plants he got F3 generation.He found out that" +"F3 generation" +"LA" +"TE" +"" +"2 3" +"1 1 2 3" +"" +"" +"" +"" +"1. A set of peas (about 25%) gave only yellow seed giving pea plants." +"2. Rest of the yellow seed giving pea plants gave about 50% yellow and" +"about 25% green seed giving pea plants." +"T" +"" +"" +"" +"3. 25% pea plants gave only green seed giving pea plants." +"Mendel made some assumptions by which he could explain his" +"ER" +"" +"" +"" +"" +"observations." +"Assumption 1: Every pea plant has two ‘factors’ which are responsible" +"for producing a particular character or trait. The determining agent" +"responsible for each trait is called a factor." +"Mendel carefully choose the plants which did not produce a mixed" +"SC" +"" +"" +"" +"" +"result (pure). In our example of yellow and green peas, a pure breed" +"(parental stage) will have both the ‘factors’ of the same type." +"A pure breed (parental) yellow seed giving pea will have both the" +"‘factors’ of the same type. Let us denote them by ‘YY’." +"A pure breed (parental) green seed giving pea will have both the ‘factors’" +"of the same type. Let us denote them by ‘yy’." +"" +"172 X Class Heredity - From parent to progeny" +" Assumption-2 : During reproduction one ‘factor’ from each parent is" +"taken to form a new pair in the progeny." +"Assumption-3 : One of these will always dominate the other if mixed" +"" +"" +"" +"" +"A" +"together. The trait expressed in F1 generation is called dominant. While" +"the other which did not express in F1 is called recessive." +"" +"" +"" +"" +"AN" +"Assume that ‘Y’ (the one causing yellow colour) is a dominating" +"‘factor’. That means if ‘Y’ and ‘y’ come together ‘Y’ will dominate. Then" +"the pea seeds will be always yellow in colour." +"From assumption-2, the breed after cross pollination will have one Parental" +"generation - Cross" +"factor from pure breed yellow (Y) and one from the pure breed green (y)." +"" +"" +"" +"" +"NG" +"pollination" +"That is, all the peas will have the paired factor ‘Yy’ and by assumption-3 all" +"the peas will be Yellow as ‘Y’ factor is dominant." +"" +"Yy ............... (yellow)" +"y y" +"Yy ............... (Yellow)" +"Y Yy Yy" +"LA" +"Yy ............... (yellow)" +"Y Yy Yy" +"Yy ............... (Yellow)" +"" +"All the pea plants are yellow (F1-Generation). The trait expressed in" +"TE" +"" +"F1 is dominant, unexpressed is recessive. This is the law of dominance." +"Self pollination in F1-Generation" +"On self pollinating these peas (ones with Yy factor), the new breed" +"have any combinations of ‘Y’ and ‘y’." +"T" +"" +"" +"" +"Y y" +"Y YY Yy" +"ER" +"" +"" +"" +"" +"y yY yy" +"It can be YY, Yy, yY or yy. All of them are in equal ratio." +"F2-Generation" +"So in this heap we will get approximately equal number of YY, Yy, yY" +"SC" +"" +"" +"" +"" +"and yy peas. But any pea that has a Y factor will be yellow. Any pea that has" +"both yy will be green. Since all combinations are equally likely:" +"1. YY will be approximately 25% and is yellow." +"2. yY will be approximately 25% and is yellow, Yy will be approximately" +"25 % and is yellow" +"3. yy will be approximately 25% and is green." +"Some seeds appear yellow in colour in F1 generation. When these" +"Free distribution by T.S. Government 2019-20 173" +" seeds were sown some of the plants produced green coloured seeds. So" +"we can’t determine internal character based on external visible character." +"" +"" +"" +"" +"A" +"Phenotype" +"Thus in F2 generation we can clearly observe that 75 percent are yellow" +"" +"" +"" +"" +"AN" +"seed producing pea plants and 25 percent are green ones. This is known as" +"‘Phenotype’(externally visible characters) and this ratio is called" +"‘phenotypic ratio’ or monohybrid phenotype ratio. It is 3:1." +"Genotype" +"Genetically, in 75 percent yellow seed producing pea plants only 25" +"" +"" +"" +"" +"NG" +"percent pea plants produce yellow seeds that are pure breeds (YY) and are" +"‘homozygous’ that is to have the same factors for representing a character." +"Remaining 50 percent yellow seed producing pea plants are (Yy)" +"heterozygous . The remaining 25 percent green seed producing pea plants" +"are pure (yy) homozygous type." +"LA" +"The constitution of pea plants as shown by the representative letters Y" +"and y to show the probable nature of factors is known as genotype. This" +"ratio is known as genotypic ratio or monohybrid genotype ratio. It is 1:2:1." +"On self-pollinating these peas of F2 generation we get," +"TE" +"" +"" +"y y" +"T" +"" +"" +"Y Y Y y" +"Y YY YY Y YY Yy y yy yy" +"Y YY YY y yY yy y yy yy" +"ER" +"" +"" +"" +"" +"1 2 3" +"" +"" +"1. The YY peas will on self pollination give only yellow (YY) peas. This" +"was explained with the experimental result that this set gave 100%" +"yellow peas." +"SC" +"" +"" +"" +"" +"2. The Yy or yY peas on self pollination give about 75% yellow peas and" +"about 25% green peas. This situation is same as step 2 ratio 3:1." +"3. The green peas that contain yy factors will give only green peas." +"In nature there are many factors responsible for different properties." +"Can we test our hypothesis with more than one factor?" +"How can this be applied to Mendel’s experiment? This can be done" +"174 X Class Heredity - From parent to progeny" +" together when two pairs of contrasting characters are taken into" +"consideration." +"1. Colour of peas-yellow and green symbolically indicated as ‘Y’, ‘y’." +"" +"" +"" +"" +"A" +"2. Shape of peas-Round and wrinkled symbolically indicated as ‘R’, ‘r’." +"The plants with yellow and round seeds (pure) were crossed with those" +"" +"" +"" +"" +"AN" +"having green and wrinkled seeds (pure)." +"" +"All pea seeds that were yellow and round. Each" +"pea will have factors ‘YyRr’. YYRR yyrr" +"" +"" +"" +"" +"NG" +"On cross pollination" +"" +"" +"" +"Since Yellow colour (Y factor) and round" +"(R factor) are dominant traits. All the pea seeds YyRr (F1)" +"LA" +"will be round and yellow (F1 generation). When" +"these plants are self pollinated." +"Self pollination" +"He got in F2 generation some seeds were" +"yellow and round (YyRr or YYRR), some seeds" +"TE" +"" +"were green and round (yyRR or yyRr), some seeds (F2)" +"were yellow and wrinkled Yyrr and some seeds" +"were green and wrinkled (yyrr)." +"What should be the percentage of each type?" +"Mendel propounded that, among a pair of closely related ‘alleles’ or" +"T" +"" +"" +"" +"factors for a character, only one expresses itself in the first generation as" +"one of the allele is dominant over the other. This is so evident that it came" +"ER" +"" +"" +"" +"" +"Dominance." +"to be called as Mendels’ Law of Dominance" +"Law of Segregation" +"As per this law for expression of each character a pair of characters or" +"alleles are responsible. Each one of these alleles is received from each" +"SC" +"" +"" +"" +"" +"parent. When this generation forms gametes, these alleles get separate" +"and each one enters into a separate gamete randomly. This separation of" +"alleles at the time of formation of gametes is called law of Segregation." +"Mendel also explained the process of inheritance of more than one" +"characters. For this, he proposed law of Independent Assortment. We" +"will learn more about this in further classes, for the basic understanding" +"refer in annexure." +"Free distribution by T.S. Government 2019-20 175" +" Traits that may be passed on from one generation to the next are called" +"as heritable traits. We have studied some of them for the pea plant, in the" +"experiments conducted by Mendel." +"" +"" +"" +"" +"A" +"Activity-4" +"" +"" +"" +"" +"AN" +"Let us do the following activity to understand the Mendelian principles" +"of Heredity." +"" +"BAG ‘A’ Materials required :" +"a) 3 cm length and 1cm breadth chart pieces- 4" +"" +"" +"" +"" +"NG" +"b) 2 cm length and 1cm breadth chart pieces- 4" +"1 2 c) Red buttons - 4" +"BAG ‘B’" +"" +"" +"" +"" +"d) White buttons - 4" +"e) Chart, scale, sketch pen, pencil, 2 bags." +"3 4 Method: Prepare a chart with 2 2 boxes along" +"LA with number and Symbol as shown in the figure" +"" +"Game 1: Monohybrid cross (starting with hybrid parents)" +"Take 4 pairs each of long and short strips and put them in two separate" +"TE" +"" +"bags. Now each bag contains 4 strips (2 long and 2 short).One bag say ‘A’" +"represents male and the bag ‘B’ represents female. Now randomly pick" +"one strip each from bag A and B and put them together in the 1 on the" +"chart. Keep picking out the strips and arrange them in the same manner till" +"your bags are empty. Sametime your boxes in the chart are filled with" +"pairs of strips. You might have got the following combinations, two long" +"T" +"" +"" +"" +"strips, one long and one short strip, two short strips." +"Conduct this activity several times and answer the following questions." +"ER" +"" +"" +"" +"" +"What is the number of long strip pairs?" +"What is the number of one long and one short pairs?" +"What is the number of short strips pairs?" +"What is the percentage of each type? also find their ratios?" +"SC" +"" +"" +"" +"" +"What can you conclude from this game?" +"You may play this game by taking buttons instead. Compare your" +"second game results with that of first game. What do you understand. Try" +"to play another game mentioned in annexure then discuss with your" +"classmates." +"" +"" +"" +"176 X Class Heredity - From parent to progeny" +" Parent to progeny" +"A person resembles his grandfather, a girl seems to be a photocopy of" +"" +"" +"" +"" +"A" +"her aunt, generally we hear such comments. These similarities are the result" +"of inherited traits transmitted from parent to progeny." +"According to Mendel traits like the colour of seed, seed coat, length" +"" +"" +"" +"" +"AN" +"of stem etc. were heritable traits from parental generation." +"Transmission or passing of characters or traits from parent to" +"offsprings is called ‘Heredity’." +"The process in which Traits are passed from one generation to another" +"" +"" +"" +"" +"NG" +"generation is called ‘Inheritance’." +"How do traits get expressed?" +"Mendel hypothesised that each character or trait is expressed due to a" +"pair of factors or ‘alleles’ (contrasting expressions of the same trait), as" +"he named them. Now we know that these are known as ‘genes’. Gene is a" +"LA" +"segment of a nucleic acid called ‘DNA’ which is present in the nucleus of" +"every cell. It controls the expression of a trait or character. In viruses" +"RNA can also be controlling the expression of a character." +"TE" +"" +"Do you know?" +"In 1953 the detailed structure of DNA was finally worked out at Cambridge by" +"Francis Crick and James Watson. They discovered that DNA molecule looks rather" +"like a spiral stair case, having a shape known as a double helix. The framework of stair" +"T" +"" +"" +"case consists of alternate sugar and phosphate groups and the steps which join the" +"framework together are the pairs of chemical compounds called bases. They are" +"adenine, guanine, thymine and cytosine. Watson and Crick were awarded Nobel prize" +"ER" +"" +"" +"" +"" +"jointly with Franklin and Maurice Wilkins." +"Traits are determined by the" +"chemical nature of DNA and a slight" +"change in it leads to variations." +"SC" +"" +"" +"" +"" +"Colour of the hair, the skin etc. are" +"examples of trait. Slight inheritable" +"changes in the chemical structure of" +"DNA may lead to change in the" +"characteristic or trait of offspring of" +"Crick DNA Watson an organism, which leads to" +"fig-3: ‘Variations’." +"" +"Free distribution by T.S. Government 2019-20 177" +" Sex determination in human beings" +"father’s sex mother’s sex We inherited our traits from our parents." +"chromosomes chromosomes" +"Let us see how sex is determined in human" +"" +"" +"" +"" +"A" +"beings. Each human cell contains 23 pairs" +"(46) of chromosomes. Out of 23 pairs 22" +"" +"" +"" +"" +"AN" +"pairs of chromosomes are autosomes." +"Chromosomes whose number and" +"morphology do not differ between males and" +"females of a species are called autosomes." +"male female" +"The remaining pair is called allosomes or sex" +"" +"" +"" +"" +"NG" +"child child" +"chromosomes. These are two types, one is" +"‘X’ and the other is ‘Y’. These two" +"Father Mother chromosomes determine the sex of an" +"Parents individual. Females have two ‘X’" +"chromosomes in their cells (XX). Males" +"44+XY" +"LA have one ‘X’ and one ‘Y’ chromosomes in" +"44+XX" +"their cells (XY). All the gametes (ova)" +"22" +"Gyno" +"22 produced by a woman have only X" +"+X +Y Andro" +"Gametes" +"Sperm Sperm 22+X" +"Eggs" +"22+X" +"chromosomes. The gametes (sperm)" +"TE" +"" +"produced by a man are of two types one with" +"X chromosome and other Y chromosome. If" +"the sperm carries Y chromosome and" +"Offsping" +"fertilizes the ovum (X chromosome). Then" +"Baby girl Baby boy Baby girl Baby boy" +"(44+XX) (44+XY) (44+XX) (44+XY) the baby will have XY condition. So the baby" +"fig-4: will be a boy." +"T" +"" +"" +"" +"What will happen if the sperm containing X chromosomes fertilizes" +"the ovum?" +"ER" +"" +"" +"" +"" +"Who decides the sex of the baby – mother or father?" +"Is the sex also a character or trait? Does it follow Mendels’ law of" +"dominance?" +"Were all your traits similar to that of your parents?" +"SC" +"" +"" +"" +"" +"Do you know?" +"Discovery of the sex chromosomes" +"Walter Setton and Thomas Hunt Morgan in the year 1956 studied on a small fruit" +"fly (Drosophila melanogaster) at Columbia University. The discovery of sex linked" +"traits in Drosophila indicated that genes are on chromosomes. They worked out the" +"details of inheritance in Drosophila." +"" +"178 X Class Heredity - From parent to progeny" +" Evolution" +"Variations develop during reproduction in organisms. Sexual" +"" +"" +"" +"" +"A" +"reproduction and errors in DNA copying leads to variations in offsprings" +"in a population. Let us try to study the consequences of variations in the" +"population of an insect in an environment." +"" +"" +"" +"" +"AN" +"Activity-5" +"Variations in beetle population" +"Observe the below diagram showing variation in beetle population and" +"" +"" +"" +"" +"NG" +"it its impact. This is only an assumption." +"" +"" +"" +"LA" +"TE" +"" +"fig-5: Variation in population in three different situations" +"Let us consider a group of twelve beetles. They live in bushes on green" +"T" +"" +"" +"leaves. Their population will grow by sexual reproduction. So they were" +"able to generate variations in population. Let us assume crows eat these" +"ER" +"" +"" +"" +"" +"red beetles. If the crows eat more Red beetles their population slowly" +"reduced." +"Let us discuss the above in three different situations in detail." +"Situation-1:" +"In this situation a colour variation arises during reproduction. So that" +"SC" +"" +"" +"" +"" +"there appears one beetle that is green in colour instead of red." +"" +"" +"" +"" +"fig-6: Red and green beetles" +"" +"Free distribution by T.S. Government 2019-20 179" +" More over this green coloured beetle passes it’s colour to it’s off" +"spring (Progeny). So that all its progeny are green. Crows cannot see the" +"green coloured beetles on green leaves of the bushes and therefore crows" +"" +"" +"" +"" +"A" +"cannot eat them. But crows can see the red beetles and eat them. As a" +"result there are more and more green beetles than red ones which decrease" +"" +"" +"" +"" +"AN" +"in their number." +"The variation of colour in beetle ‘green’ gave a survival advantage to" +"‘green beetles’ than red beetles. In other words it was naturally selected." +"We can see that the ‘natural selection’ was exerted by the crows. The more" +"crows there are, the more red beetles would be eaten and the more number" +"" +"" +"" +"" +"NG" +"of green beetles in the population would be. Thus the natural selection is" +"directing evolution in the beetle population. It results in adaptation in the" +"beetle population to fit in their environment better." +"Let us think of another situation." +"Situation-2:" +"LA" +"In this situation a colour variation occurs again in its progeny during" +"reproduction, but now it results in ‘‘Blue’" +"Blue colour beetles instead of ‘red’" +"colour beetle. This blue colour beetle can pass its colour to its progeny." +"So that all its progeny are blue." +"TE" +"T" +"" +"" +"fig-7: Blue and red beetle" +"" +"Crows can see blue coloured beetles on the green leaves of the bushes" +"ER" +"" +"" +"" +"" +"and the red ones as well. And therefore crows can eat both red and blue" +"coloured beetles. In this case there is no survival advantage for blue" +"coloured beetles as we have seen in case of green coloured beetles." +"What happens initially in the population, there are a few blue beetles," +"but most are red. Imagine at this point an elephant comes by and stamps on" +"SC" +"" +"" +"" +"" +"the bushes where the beetles live. This kills most of the beetles. By chance" +"the few beetles survived are mostly blue. Again the beetle population slowly" +"increases. But in the beetle population most of them are in blue colour." +"Thus sometimes accidents may also result in changes in certain characters" +"of the a population. Characters as we know are governed by genes. Thus" +"there is change in the frequency of genes in small populations. This is" +"known as “Genetic drift’, which provides diversity in the population." +"180 X Class Heredity - From parent to progeny" +" Let us think of another situation:" +"Situation-3:" +"" +"" +"" +"" +"A" +"AN" +"fig-8: Poorly nourished beetles" +"" +"In this case beetles population is increasing, but suddenly bushes were" +"" +"" +"" +"" +"NG" +"affected by a plant disease in which leaf material were destroyed or in" +"which leaves are affected by this beetles got less food material. So beetles" +"are poorly nourished. So the weight of beetles decrease but no changes" +"take place in their genetic material (DNA). After a few years the plant" +"disease are eliminated. Bushes are healthy with plenty of leaves." +"What do you think will be condition of the beetles?" +"LA" +"Acquired and Inherited Characters and Evolution" +"We discussed the idea that the germ cells of sexually reproducing" +"population are formed in specialised reproductive tissue. If the weight of" +"TE" +"" +"the beetles is reduced because of starvation, that will not change the DNA" +"of the germ cells. Therefore, low weight is not a trait that can be inherited" +"by progeny of a starving beetle. Therefore even if some generations of" +"beetles lose their weight because of starvation, that is not an example of" +"evolution, since the change is not inherited over generations. Change in" +"non reproductive tissues cannot be passed on to the DNA of the germ" +"T" +"" +"" +"" +"cells. Therefore the experiences of an individual during its lifetime cannot" +"be passed on to its progeny, and cannot direct evolution." +"ER" +"" +"" +"" +"" +"Lamarckism" +"In the olden days people believed that all the organisms on the" +"earth had not undergone any change. Jean Baptist Lamarck was the" +"first person to propose the theory of evolution. He thought that at" +"some point of time in the history the size of giraffe was equal to" +"SC" +"" +"" +"" +"" +"that of deer. Due to shortage of food material on the ground and to" +"reach the lower branches of trees giraffes started stretching their" +"necks. Because of continuous stretching of neck, after several" +"generations giraffes developed long necks. Such characters that fig-9:" +"are developed during the lifetime of an organism are called Jean Baptist Lamarck" +"‘acquired characters’. Lamarck proposed that these acquired (1774-1829)" +"" +"Free distribution by T.S. Government 2019-20 181" +" characters are passed on to its offsprings i.e. to next generation" +"and proposed the theory of ‘Inheritance of acquired characters’." +"For example elongation of neck and forelimbs in giraffe." +"" +"" +"" +"" +"A" +"But August Weismann, tested this theory by an experiment on" +"rats. He removed tails of parental rats. He observed that their" +"" +"" +"" +"" +"AN" +"offspring’s are normal with tails. He has done it again and again" +"for twenty two generations but still offsprings are normal with" +"tails. He proved that the bodily changes are not inherited. So they" +"won’t be passed to it’s offsprings." +"" +"" +"" +"" +"NG" +"fig-10: Giraffee Darwinism" +"Charles Darwin proposed ‘Natural selection’ the famous ‘theory of" +"evolution’." +"Charles Darwin (1809-1882) was born in England. He voyaged" +"for five years, just when he was 22 years old. In the world survey" +"LA" +"ship HMS Beagle. He visited a number of places including" +"Galapagos Islands. He keenly observed the flora and fauna of these" +"places. He gathered a lot of information and evidences." +"Darwin observed a small group of related birds which are" +"exhibiting diversity in structure in the Galapagos islands. These" +"TE" +"" +"birds are Finch birds. Observe the fig-12. How do the beaks help" +"fig-11: Charles Darwin them." +"(1809 – 1882) He was influenced by the book ‘Principles of geology’ written" +"by Sir Charles Lyell. He suggested that geological changes occured" +"T" +"ER" +"" +"" +"" +"" +"Large ground finch (seeds) Cactus ground finc" +"finch Vegetarian finch (buds) Wood pecker finch (insects)" +"SC" +"" +"" +"" +"" +"fig-12: Some Darwin finches" +"in a uniform rate, Darwin did not agree to this idea. He felt that large" +"changes occured due to accumulation of small changes. Darwin was also" +"influenced by the famous ‘Malthus theory’. This was written in ‘An essay" +"on the principles of population’. Malthus observed that population grows" +"in geometrical progression (1, 2, 4, 8, ......) where as food sources increases" +"in arithmetic progression (1, 2, 3, 4, 5, .......)." +"182 X Class Heredity - From parent to progeny" +" Based on these ideas, Darwin proposed the theory of “Natural" +"selection”, which means that the nature only selects or decides which" +"organism should survive or perish in nature. This is the meaning of survival" +"" +"" +"" +"" +"A" +"of the fittest. The organisms with useful traits will survive. If traits are not" +"usefull to organisms then they are going to be perished or eliminated from" +"" +"" +"" +"" +"AN" +"its environment." +"Alfred Russel Wallace also independently concluded that natural" +"selection contributed to origin of new species. For example we have seen" +"in the case of red beetles which were seen and eaten by crows. So, the" +"population of red beetles gradually got eliminated or perished from its" +"" +"" +"" +"" +"NG" +"environment. But at the same time the beetles which are green in colour" +"which are present on the green leaves were not noticed by crows. So the" +"green beetles survived in the environment and their population have" +"gradually increased. This is nothing but “natural selection”." +"LA" +"Think and discuss" +"" +"In a forest there are two types of deers, in which one type of deer can run" +"very fast. Where as second type of deer can not run as fast as the first one. Lions," +"Tigers hunt deers for their food. Imagine which type of deers are going to survive in" +"TE" +"" +"the forest and which type of deers population is going to be eliminated? And why?" +"Variations which are useful to an individual are retained, while those" +"which are not useful are lost. In a population when there is a struggle for" +"the existence the ‘fittest’ will be survived." +"Nature favours only useful variations. Each species tend to produce" +"T" +"" +"" +"large number of offsprings. They compete with each other for food, space," +"mating and other needs. In this struggle for existence, only the fittest can" +"survive." +"ER" +"" +"" +"" +"" +"This is called ‘survival of the fittest’. Over a long period of time this" +"leads to the formation of new species." +"You may observe in your surroundings some seedlings and some of" +"the animal kids only survive. Discuss in your class based on those examples" +"SC" +"" +"" +"" +"" +"to understand survival of the fittest." +"Darwin’s theory of evolution in a nutshell" +"1. Any group of population of an organism develops variations and all" +"members of group are not identical." +"2. Variations are passed from parent to offspring through heredity." +"3. The natural selection over abundance of offspring leads to a constant" +"struggle for their survival in any population." +"Free distribution by T.S. Government 2019-20 183" +" 4. Individuals with variations that help them to survive and reproduce tend" +"to live longer and have more offsprings than organisms with less use-" +"ful features." +"" +"" +"" +"" +"A" +"5. The offsprings of survivors inherit the useful variations, and the same" +"process happens with every new generation until the variation becomes" +"" +"" +"" +"" +"AN" +"a common feature." +"6. As the environment changes, the organism within the environment adapt" +"and changes to the new living conditions." +"7. Over a long period of time, each species of organism can accumulate" +"so many changes that it becomes a new species, similar to but dis-" +"" +"" +"" +"" +"NG" +"tinctly different from the original species. All species on the earth" +"arise in this way." +"8. Evolution is a slow and continuous process." +"There are some limitations and objections to the Darwin theory. Many" +"new theories like synthetic theory, mutation theory are put forward." +"LA" +"Do you know?" +"Identical thoughts of Charles Darwin and Alfred Russel Wallace." +"When Charles Darwin was formulating the theory of" +"TE" +"" +"evolution in his mind, he received a letter with an article sent" +"by Alfred Russel Wallace about his studies in the Indonesian" +"island. The article was about Natural selection. Darwin was" +"surprised about same theory in his mind. Later in the same" +"year Charles Darwin and Alfred Wallace jointly published an" +"article in the ‘Journal of Linnaean Society’ about natural" +"T" +"" +"" +"" +"selection. It was only after this Darwin published his famous" +"Alfred Russel Wallace bbook," +"ook, “The origin of Species” in 1859. However their thoughts" +"ER" +"" +"" +"" +"" +"gained criticism at that time because they did not explain how variations are inherited." +"After the discovery of mitosis and meiosis it was understood properly." +"" +"Speciation" +"How new species are evolved?" +"SC" +"" +"" +"" +"" +"We have seen variations in a population of species, where the organism" +"contain the traits that helped to adapt to the environment. These organisms" +"are going to survive more efficiently. But in the same population the" +"organism which contains the non beneficial traits may not be adapted in" +"the environment. They are going to perish or eliminated slowly, like red" +"and blue beetles in a population which we have discussed earlier in this" +"chapter. These small changes within the species for example colour of" +"184 X Class Heredity - From parent to progeny" +" beetles red and green is known as micro evolution." +"Now we are going to discuss how new species are formed. This is" +"known as speciation, which is also known as Macroevolution." +"" +"" +"" +"" +"A" +"We have seen red and green beetles can mate each other and can have" +"offsprings. But let us imagine that red and green beetles are separated by" +"" +"" +"" +"" +"AN" +"some cause (for example while eating beetles crows dropped some beetles" +"accidently in the long distance far away places) for long years. There might" +"be a lot of variations taken place in these years in the red and green beetle" +"population. Now even though they may meet accidentally, they cannot mate" +"and produce new offsprings. They can only mate in their population either" +"" +"" +"" +"" +"NG" +"red or green and can reproduce its off spring. Thus new species have been" +"formed." +"Evidences of evolution" +"How does the evolution of organisms taken place? Whatever scientists" +"propose they require evidences or proofs. In the same way evolution of" +"LA" +"organisms requires evidences. Let us examine some of them." +"Homologous and analogous organs" +"When we try to understand evolutionary relationships, we identify that" +"some traits have common ancestors. These traits in different organisms" +"TE" +"" +"would be similar because they are inherited from a common ancestor. You" +"may be surprise to know that the internal structure of forelimb of a whale" +"(swimmer) wing of a bat (flyer), leg of a cheetah (runner), claw of a mole" +"(digger) and hand of a man (grasping). If we carefully observe the anatomy" +"of all these animals, they show a common" +"T" +"" +"" +"pattern in the arrangement of bones, even" +"though their external form and functions are" +"ER" +"" +"" +"" +"" +"different. It indicates that all the vertebrates" +"have evolved from a common ancestor and" +"these organs are called homologous organs." +"This type of evolution is called divergent" +"evolution." +"SC" +"" +"" +"" +"" +"However, all similarities simply in organ" +"shape are not necessarily to have a common" +"ancestry. What would we think about the wings" +"of birds and bats, for example (fig-). Birds and" +"bats have wings, but squirrels and lizards do" +"not. So birds and bats are more closely related" +"fig-13: Homologous organs" +"to each other than squirrels or lizards." +"Free distribution by T.S. Government 2019-20 185" +" Before we jump into this conclusion, let us look at the wings of birds" +"and bats more closely. When we observe, we find that the wings of bats" +"have skin folds (patagium) stretched between elongated fingers. But the" +"" +"" +"" +"" +"A" +"Insect wing wings of birds have a feathery covering all along the arm. The designs of" +"the two wings, their structure and components are different. They look" +"" +"" +"" +"" +"AN" +"similar because they have a common use for flying, but their origin is not" +"common. This gives the ‘analogous’ characteristics (Traits). As the above" +"Bird wing mentioned organs which are structurally different but functionally similar" +"Analogous are known as ‘Analogous" +"Analogous organs’. This type of evolution is called convergent" +"organs evolution." +"" +"" +"" +"" +"NG" +"Evidences from embryology" +"" +"Activity-6" +"Let us observe different stages of development of vertebrate embryos." +"Try to find out similarities and differences and discuss with your friends." +"LA" +"Embryology is the study of embryos and their" +"development. Tadpole of a frog resembles fish" +"more than the frog. What does this indicates?" +"Does it indicate that frogs have evolved from" +"TE" +"" +"ancestors of fish?" +"There are remarkable similarities in the" +"embryos of different animals from fish to man." +"The resemblance is so close that at an early stage" +"even an experienced embryologist would find" +"T" +"" +"" +"fish Salamander Tortoise Chick Pig Calf Rabbit Human difficulty to distinguish one embryo from the" +"other. What does it indicate? Does it indicate" +"fig-14: Embryological evidences" +"ER" +"" +"" +"" +"" +"that life history of every individual, exhibits the" +"structural features of their ancestors? This strengthens the view of the" +"existence of a common ancestor from which all these have evolved." +"Evidences from fossils" +"We know some species which existed million years ago, but we may" +"SC" +"" +"" +"" +"" +"not find them now. They might be extinct and some of them may be found" +"in the form of fossils. For example we know Dinosaurs the biggest animal" +"on land which were present long time ago but now they are extinct. The" +"scientists got evidences of presence of Dinosaurs like animals in the form" +"of fossils." +"" +"" +"186 X Class Heredity - From parent to progeny" +" What are fossils?" +"Fossils are evidences of ancient life forms or ancient habitats" +"which have been preserved by natural processes. Fossil evidence" +"" +"" +"" +"" +"A" +"is typically preserved within the sediments deposited beneath" +"water and land. They can be actual remains of once lived such as" +"" +"" +"" +"" +"AN" +"bones or seeds or even traces of past event such as dinosaur foot" +"print or ripple marks on a pre-historic shore. Usually when" +"organisms die, their bodies will be decomposed and lost." +"fig-15: Fossil" +"Sometimes the body or some parts of the body do not decompose" +"completely. For example if a dead insect get caught in mud, it will not" +"" +"" +"" +"" +"NG" +"decompose quickly and the mud will eventually harden and retain the" +"impression of the body parts of insect. All such preserved traces of extinct" +"organisms are called fossils." +"Geologists can tell the age of a fossil. The" +"study of fossil is called ‘Palaeontology’." +"LA" +"Palaeontologists determine the age of fossil" +"by using carbon dating method. The breakdown" +"of radioactive isotopes of certain elements" +"such as Carbon, Uranium and Potassium takes" +"TE" +"" +"place at a known rate. So the age of rock or" +"mineral containing isotopes can be calculated." +"Collect information about radio carbon dat-" +"ing method and radioactive isotopes and" +"discuss with your teacher or from library fig-16: Dinosaur" +"display your collections in your class." +"T" +"" +"" +"" +"A rare and magnificient fossil of the dinosaurs, ketosaurs belonging" +"to the lower Jurassic age going back to about 160 million years were" +"ER" +"" +"" +"" +"" +"collected from Yamanapalli in Adilabad district of Telangana. This fossil" +"has 14 metres length and 5 metres height. This fossil is preserved at BM" +"Birla Science Centre in Hyderabad." +"" +"Do you know?" +"SC" +"" +"" +"" +"" +"See the picture of Archeopteryx. Does it" +"resemble a bird? Or a reptile? Or both? The" +"organisms which bear the characters of two" +"different groups are called connecting links." +"Archeopteryx has some avian characters and some" +"reptelian characters. Hence it is recognised as Archeopteryx" +"connecting link between aves and reptiles." +"Free distribution by T.S. Government 2019-20 187" +" Human evolution Human evolution is the evolutionary process" +"Diopithicus leading up to the appearance of a modern human" +"15 million years being. We the present human beings are also have" +"" +"" +"" +"" +"A" +"Ramapithicus an evolutionary history like plant and other" +"2 million years animals. Early man like forms appeared about 7" +"Astrolopithicus" +"" +"" +"" +"" +"AN" +"lakhs 50 thousand years ago. The first sure fossil" +"Homo habilus sapiens," +"of our own species of man the Homo sapiens" +"1.6 - 2.5 million years indicate that true man appeared on the earth 2" +"Home erectus lakhs 50 thousand years ago." +"1 - 1.8 million years Evolution of man through ages:" +"Homo Homo habilus lived between 1.6 - 2.5 million" +"" +"" +"" +"" +"NG" +"Neanderthalensis" +"1,00,000 to 40,000 thousand years years ago." +"Cromagnan Homo erectus lived between 1 - 1.8 million" +"15,000 to 10,000 thousand years years ago." +"Homo sapiens Homo sapiens neanderthalensis lived between" +"(modern man)" +"1,00,000 - 40,000 thousands years ago." +"LA" +"Homo sapiens (present man) appeared about 10 thousand years ago." +"There is a great diversity in human forms and features across the planet." +"So that for a long time, people used to talk about human ‘races’. Skin colour" +"used to be the commonest way of identifying the so called races. Some" +"were called black, some white or brown. A major question debated for" +"TE" +"" +"long time was, have these apparent groups evolved differently? Over recent" +"years, the evidence has become very clear. The answer is that there is no" +"biological basis to the notion of human races. All humans are a single" +"species with a common ancestor." +"Not only that, regardless of where we have lived for the past few" +"T" +"" +"" +"thousand years, we all come from Africa. The earliest members of the" +"human species, Homo sapiens, can be traced there. Our genetic footprints" +"ER" +"" +"" +"" +"" +"can be traced back to our African roots. A couple of hundred thousand" +"years ago, some of our ancestors left Africa while others stayed on, while" +"the residents spread across Africa. The migrants slowly spread across the" +"planet –from Africa to west Asia, Then to Central Asia, Eurasia, South" +"Asia, East Asia. They travelled down the island of Indonesia and the" +"SC" +"" +"" +"" +"" +"Philippines to Australia, and they crossed the Bering land bridge to the" +"Americas. They did not go in a single line, so were not travelling for the" +"sake of travelling, obviously. They went forwards and backwards, with" +"groups sometimes separating from each other, even moving in and out of" +"Africa. Like all other species on planet, they had come into being as an" +"accident of evolution, and were trying to live their lives the best they could." +"" +"" +"188 X Class Heredity - From parent to progeny" +" Think why did ancient human beings travelled from one place to" +"other and how did they travelled?" +"Human being - a moving museum" +"" +"" +"" +"" +"A" +"During the course of evolution some organs remain in the organisms." +"You have studied about appendix in the digestive system. In human beings" +"" +"" +"" +"" +"AN" +"it has no role to play in the process of digestion. But in herbivores like" +"rabbit appendix plays an important role. Such type of organs which are not" +"useful in animal are called vestigial organs." +"Sometimes vestigal organs are abruptly appears even in humanbeings." +"This phenomenon is called “ATAVISM”. Ex : baby with tail." +"" +"" +"" +"" +"NG" +"There are nearly 180 vestigial organs in human beings. For example" +"pinna, hair on skin, mammary glands in males, etc. That’s why human being" +"is said to be a moving museum of vestigial organs." +"" +"Key words LA" +"Variations, offsprings, traits, phenotype, genotype, heterozygous, homozygous," +"independent assortment, allele, heredity, autosomes, allosomes, natural selection," +"analogous organs, embryological evidences, Human evolution." +"TE" +"" +"What we have learnt" +"Variations are quite apparent among closely related groups of organisms." +"In about 1857 Gregor Johann Mendel started working on the problem of how variations were" +"passed from one generation to other." +"Mendel had choosen seven distinguishing traits: flower colour, position, seed colour, shape, pod" +"T" +"" +"" +"colour, pod shape, stem length." +"In monohybrid experiment F1 generation express dominant trait (Eg: Yellow seeds)." +"In F2 generation about 75% seeds were with dominant character (Eg: Yellow seeds) and about" +"ER" +"" +"" +"" +"" +"25% seeds were with recessive character (Eg: Green seeds). This is called phenotype and the ratio" +"is 3:1." +"In F2 generation out of 75%, 25% were pure yellow seeds 50% were yellow seeds but green as" +"a recessive factor. Remaining 25% were pure green. This is called genotype and the ratio 1:2:1." +"Every pea plant has two ‘factors’ which are responsible for producing a particular property or trait" +"SC" +"" +"" +"" +"" +"called allele." +"The factors for each pair of characters assorts independently of the other pairs. This is known as" +"“Law of independent assortment”." +"Crossing yellow and green seeds produced all yellow seeds. Because yellow is dominant factor." +"Each parent passes randomly selected copy (allele) of only one of these to its offspring." +"The process of acquiring characters or traits from parents is called ‘Heredity’." +"Each human cell contains 23 pairs of chromosomes. Out of these 22 pairs are called autosomes" +"and one pair is called allosomes." +"Free distribution by T.S. Government 2019-20 189" +" Lamarck proposed that the acquired characters are passed to the offspring in the next generation." +"Each species tend to produce large number of offsprings, but only the fittest can survive." +"Homologous, analogous organs and embryological evidences explain evolutionary relationships." +"" +"" +"" +"" +"A" +"Some traits in different organisms would be similar because they are inherited from a common" +"ancestor." +"" +"" +"" +"" +"AN" +"Fossils are evidences of ancient life forms or ancient habitats which have been preserved by natural" +"processes." +"" +"" +"Improve your learning" +"" +"" +"" +"" +"NG" +"1. What are variations? How do they help organisms?(AS1)" +"2. One student (researcher) wants to cross pure tall plant (TT) with pure dwarf (tt) plant, what would" +"be the F1 and F2 generations? Explain.(AS1)" +"3. One experimenter cut the tails of parent rats , what could be the the traits in offsprings? Do the" +"daughter rats contain tails or not? Explain your argument.(AS1)" +"4. In a mango garden a farmer saw one mango tree with full of mango fruits but with a lot of pests. he" +"LA" +"also saw another mango tree without pests but with few mangoes. But the farmer wants the mango" +"tree with full of mango fruits and pest free. Is it possible to create new mango tree which the farmer" +"wants? Can you explain how it is possible?(AS1)" +"5. Explain monohybrid experiment with an example, which law of inheritance can we understand?" +"TE" +"" +"Explain.(AS1)" +"6. What is the law of independent assortment? Explain with an example?(AS1)" +"7. Explain the Darwin’s theory of evolution ‘Natural selection’ with an example?(AS1)" +"8. What are variations? Explain with a suitable example.(AS1)" +"9.What variations generally have you observed in the species of cow?(AS1)" +"10. What are the characters Mendel selected for his experiments on pea plant?(AS1)" +"T" +"" +"" +"11. In what way Mendel used the word ‘Traits’- explain with an example.(AS1)" +"12. What differences Mendel identified between parent and F2 generation.(AS1)" +"ER" +"" +"" +"" +"" +"13. Male is responsible for sex determination of baby – do you agree? If so write your answer with a" +"flow chart.(AS1)" +"14. Write a brief note on analogous organs.(AS1)" +"15. How do scientists utilise the information about fossils?(AS1)" +"16. Mendel selected a pea plant for his experiments. Mention the reasons in your point of view.(AS2)" +"17. If the theory of inheritance of acquired characters proposed by Lamark was true how will the" +"SC" +"" +"" +"" +"" +"world be?(AS2)" +"18. Collect information on the inherited traits in your family members and write a note on it.(AS4)" +"19. Observe flowering plants in your surroundings? Write similarties and differences between them?" +"20. With the help of given information write your comment on evidences of evolution.(AS4)" +"Mammals have four limbs as do birds, reptiles and amphibians. The basic structure of the limbs is" +"similar, though it has been modified to perform different functions." +"21. Collect information about carbon dating method. Discuss with your physical science teacher.(AS4)" +"190 X Class Heredity - From parent to progeny" +" 22. Draw a checker board show the law of independent assortment with a flow chart and explain the" +"ratio.(AS5)" +"23. Explain the process to understand monohybrid cross of Mendel experiment with a checker" +"" +"" +"" +"" +"A" +"board.(AS5)" +"24. Prepare a flow chart showing evolution of man through ages.(AS5)" +"" +"" +"" +"" +"AN" +"25. Nature selects only desirable characters. Prepare a cartoon.(AS6)" +"26. What is your understanding about survival of the fittest. Give some situations or examples that you" +"observe in your surroundings?(AS7)" +"27. Write a monologue on evolution of a man to perform a stage show on the theatre day in your" +"school.(AS7)" +"" +"Fill in the blanks" +"" +"" +"" +"" +"NG" +"1. The process of acquiring character or traits is called ______________." +"2. Mendel’s experiment explains about ______________." +"3. The four characters observed in the experiments on law of independent assossment are __________." +"LA" +"4. If we cross pollinate red flower plant with white flower we will get ________ percent of recessive" +"trait plants." +"5. TT or YY, Tt or Yy are responsible for a _________________ character." +"6. Humans have __________ pairs of autosomes and _______ pair of sex chromosomes." +"TE" +"" +"7. The population grows in ________________ progression where as food sources grow in" +"_______________ progression." +"8. A goat which can’t walk properly can’t live for a long time. According to Darwin this represents" +"_______________." +"9. Forelimb of whale is for swimming where as in horse it is used for _______________." +"10. The study of fossils is called _______________." +"T" +"" +"" +"" +"Choose the correct answer" +"ER" +"" +"" +"" +"" +"11. Which of the following is not a variation in rose plant. ( )" +"A) Coloured petals B) Spines C) Tendrils D) Leaf margin" +"12. According to Mendel alleles have the following character. ( )" +"A) Pair of genes B) Responsible for character" +"SC" +"" +"" +"" +"" +"C) production of Gametes D) Recessive factors" +"13. Natural selection means ( )" +"A) Nature selects desirable characters B) Nature rejects undesirable characters" +"C) Nature reacts with an organism D) A, B" +"14. Palaeontologists deal with ( )" +"A) Embryological evidences B) Fossil evidences" +"C) Vestigial organ evidences D) all" +"Free distribution by T.S. Government 2019-20 191" +" Annexure-I" +"" +"" +"" +"" +"A" +"Mendel’s laws of independent assortment" +"" +"" +"" +"" +"AN" +"Till now we have discussed about the Mendel’s" +"RY Ry ry rY" +"hypothesis with monohybrid cross. Mendel’s also" +"tried to understand the inheritance of two pairs of RR YY RR Yy Rr Yy Rr YY" +"characters together. In this dihybrid cross, parents RY" +"" +"produce offsprings containing the factors for" +"RR Yy RR yy Rr yy Rr Yy" +"" +"" +"" +"" +"NG" +"Characters (traits) of Yellow (YY), Round (RR), and Ry" +"wrinkled (rr), green (yy). These characters appeared" +"Rr Yy Rr yy rr yy rr Yy" +"independently without mixing with each other in F2 ry" +"generation, which were produced by self pollination" +"in F1 generation. Rr YY Rr Yy rr Yy rr YY" +"rY" +"LA" +"Observe thc checker board given here carefully" +"and note down different combinations of characters" +"9 :3 :3 :1" +"resulted from dihybrid cross." +"1. RRYY, 2. RRYy, 3. RrYY, 4. RrYy, 5. RRYy, Round yellow Wrinkled, yellow" +"" +"Round, green Wrinkled, green" +"6. RrYY, 7. RrYy, 8. RrYy, 9. RrYy are having Round" +"TE" +"" +"and Yellow seeds." +"1. RRyy, 2. Rryy, 3. Rryy have Round and Green seeds" +"1. rrYY, 2. rrYy, 3. rrYy have Wrinkled and Yellow seeds" +"1. rryy have Wrinkled and Green seeds" +"From the above results it can be concluded that the factors for each character or trait" +"T" +"" +"" +"" +"remain independent and maintain their identity in the gametes. The factors are independent" +"to each other and passes to the offsprings (through gametes)." +"ER" +"" +"" +"" +"" +"In the inheritance of more than one pair of characters (traits), the factors for each pair" +"of characters assorted independently of the other pair. This is known as “Law of independent" +"assortment”." +"assortment ”." +"Mendel believed that every character or trait is controlled or responsible by a pair of" +"factors. The factors which are responsible for a character or trait of an organism, now" +"SC" +"" +"" +"" +"" +"‘genes’. The pair of genes which are responsible for a character are called as" +"named as ‘genes" +"‘alleles’." +"‘‘alleles" +"alleles Alleles are of two types one is homozygous type (YY or RR) and the other is" +"heterozygous (Yy or Rr Rr)." +"" +"" +"" +"" +"192 X Class Heredity - From parent to progeny" +" A" +"Chapter" +"" +"" +"" +"" +"AN" +"9" +"" +"" +"NG" +"Our environment - Our concern" +"LA" +"Everyone is familiar with one’s own surrounding. It plays an important" +"role in the survival of all organisms. The sum of physical and biological" +"factors along with their chemical interactions that affect an organism is" +"called environment. The living organisms always try to maintain a balance" +"among them selves and with biotic and abiotic factors. All components of" +"TE" +"" +"biosphere interact in an organized manner with the organisms. This" +"interaction assures an organism to survive that may result in gradual" +"evolution of the organisms in the biosphere. The physical factors refer to" +"abiotic factors (land, air, water sun light etc) and biological factors to" +"biotic factors (flora and fauna). The place where an organisms lives is" +"T" +"" +"" +"called habitat. An organism can’t completely defy the balance to suit one’s" +"need. It would in some way or the other affect the balance in such a way" +"ER" +"" +"" +"" +"" +"that the survival of the organism affecting the damage would be at stake." +"You have understood the relationships between" +"organisms and their food in earlier classes with" +"the help of food chains and food webs. Food chains" +"are interconnected and when we try to observe" +"SC" +"" +"" +"" +"" +"these connections among a number of food chains" +"then it becomes a food web. As you know a food" +"chain shows who eats what in a particular habitat." +"The arrows between two organisms in the chain" +"always point from the food to the feeder." +"If we want to show a food chain consisting of" +"grass, snake, rabbit and hawk then connect the given fig-1: Food relationship" +"" +"Free distribution by T.S. Government 2019-20 193" +" organisms by putting arrows and make a food chain." +"Name the producer and consumers in the above food chain." +"Try to guess what does the arrows marked by you indicate?" +"" +"" +"" +"" +"A" +"Identify at least four other food chains in your surroundings. Name" +"the producers and different levels of consumers in those food chains." +"" +"" +"" +"" +"AN" +"While identifying different food chains in your surroundings you will" +"find that most of the food chains are quite short and they rarely consists" +"of not more than four steps. You will also notice that as we move from" +"producer to consumers (primary, secondary & tertiary) in a food chain the" +"numbers of organisms at each level decreases." +"" +"" +"" +"" +"NG" +"What type of relationships exist among the biotic components? In an" +"Sun" +"ecosystem the energy rich food passes from producers to consumers" +"stepwise, with respect to their (food) relationships." +"" +"Primary Secondary Tertiary Top" +"Producer" +"LA Consumer Consumer Carnivore" +"Consumer" +"" +"Examples" +"Grass grasshopper frog snake Hawk" +"TE" +"" +"Grass Rabbit Fox Wolf" +"Grass Goat Man" +"Why do most of the food chains consist of four steps?" +"Why do the number of organisms get decreased as we move form" +"producer to different level of consumers?" +"T" +"" +"" +"To get answers for the above question we have to recall some of the" +"things which have been discussed in the earlier classes. In chapter 7" +"ER" +"" +"" +"" +"" +"“Different Ecosystems” of class 8th it was mentioned that all organisms in" +"an ecosystem derive energy from food to live and sunlight is the main" +"source of the energy. Food chain shows that how the energy is passed" +"from one organism to another. At each transfer a large proportion (80 to" +"90 percent) of energy is dissipated as heat produced during the process of" +"SC" +"" +"" +"" +"" +"respiration and other reactions. After three steps in a food chain, very" +"little energy is still available for top carnivores to use." +"Within the biosphere there are a number of major ecosystems. The" +"terrestrial ecosystems are determined largely by the variations in climatic" +"conditions between the Poles and Equator. In a similar way, if you climb a" +"mountain such as Kilimanjaro in Equatorial Africa or Himalayan mountains" +"in our country. You quickly go through a comparable system of ecosystems," +"194 X Class Our environment - Our concern" +" starting with tropical rain forest at the base and ending" +"with perpetual snow and ice at the summit." +"The main climatic influences which determine these" +"" +"" +"" +"" +"A" +"ecosystems are rainfall, temperature and the availability" +"of light from the sun. For instance, forests are usually" +"" +"" +"" +"" +"AN" +"associated with high rainfall, but the type of forest is" +"influenced by temperature and light. The same applies" +"to deserts which occur in regions where rainfall is" +"extremely low." +"But these links are never as simple or rigid as the" +"" +"" +"" +"" +"NG" +"word ‘chain’ suggests. For example, aphids are eaten by" +"many insectivorous birds in addition to warblers, and also" +"ladybirds and other insects; hawks, on the other hand, forest pond" +"prey upon a considerable variety of birds and small grassland" +"mammal-So the term food web is often a better one to fig-2: Food chains in different" +"LA" +"use when being precise, as it suggests a far greater number ecosystems" +"of possible links and reflects the fact that the whole" +"community is a complex inter-connected unit. Thus the original energy from" +"the sun flows through the whole ecosystem from one tropic level to another." +"TE" +"" +"Let us observe the diagram (fig-2) which shows some of the feeding" +"relationships amongst organisms living in deciduous woodland. You will" +"see from the diagram that animals fit into special positions within the" +"food web; each is described as its niche. For instance, there is a niche for" +"insects such as aphids which suck up the juices of leaves. Another niche" +"for insects such as caterpillars which have strong jaws for biting off pieces" +"T" +"" +"" +"of a leaf and a niche for relatively large animals such as deer which browse" +"on the vegetation. All these animals feed on leaves but they differ both in" +"ER" +"" +"" +"" +"" +"size and in the manner in which they feed. So the term ‘niche’ denotes not" +"only the animal’s position in the food web and what it eats, but also its" +"mode of life. Just as a habitat is the place where an animal lives, so a niche" +"describes its occupation the way it ‘goes about its business and earns its" +"livings." +"SC" +"" +"" +"" +"" +"Discuss one more example of niche with your teacher." +"Food Web" +"In nature food chains are usually not simple and linear. They are often" +"branched, because at every stage or trophic level consumers have several" +"alternative forms of food to choose from. For example, in the fig.-3 snakes" +"prey upon frogs, mice and small birds. Similarly, cranes prey upon fish" +"Free distribution by T.S. Government 2019-20 195" +" and frogs. As a result, food chains become branched" +"and interlinked at various stages leading to a web-" +"like structure. This is called a food web." +"" +"" +"" +"" +"A" +"Observe the figure of the given food web" +"and draw two (2) food chains basing on the food" +"" +"" +"" +"" +"AN" +"web." +"Ecological pyramids" +"Apart from the food chains pyramids are another" +"type of representations which show flow of energy" +"" +"" +"" +"" +"NG" +"from one organism to another. You may have heard" +"about pyramids of Egypt. The ecologists also used" +"this idea of pyramid to show relationship among" +"organisms in an existing food chain. In short we can" +"fig-3: Food web say that graphic representation of the feeding level" +"(tropic level) of an ecosystem in the shape of a" +"LA" +"pyramid is called “Ecological pyramid”. It was first introduced by a British" +"ecologist Charles Elton in 1927. In the ecological pyramid the producers" +"(first trophic level) are represented at the base; and other successive trophic" +"levels (primary, secondary and tertiary consumers) are represented one" +"TE" +"" +"above the other with top carnivores at the tip. There are three types of" +"pyramids; pyramid of biomass, pyramid of number, pyramid of energy. In" +"this chapter we will try to discuss about the pyramid of number, biomass" +"and energy." +"Do you know?" +"T" +"" +"" +"" +"A pyramid is a structure whose shape is roughly that of a pyramid in the geometric" +"sense; that is, its outer surfaces are triangular and converge to a single point at the" +"ER" +"" +"" +"" +"" +"top. The base of a pyramid can be trilateral, quadrilateral or polygonal shape. The" +"square pyramids, with square base and four triangular outer surfaces, is a common" +"version." +"Pyramid of numbers" +"SC" +"" +"" +"" +"" +"Tertiary" +"Biologists are not only interested in studying the food" +"relationships which exists between living things, but also in" +"Secondary comparing the numbers of organisms at each link in the chain." +"Here is an example of food web to make estimates of the" +"Primary" +"comparative numbers of organisms present at each stage of" +"Producers chain. The comparison needs to involve the use of such terms" +"fig-4: Pyramid of numbers as most, many, several, few and scarce. Is there any relationship" +"196 X Class Our environment - Our concern" +" between the numbers?Is there any" +"comparison that could be made about the" +"sizes of the organisms involved at each" +"" +"" +"" +"" +"A" +"stage." +"The number of organisms in a food chain" +"" +"" +"" +"" +"AN" +"can be represented graphically in a pyramid." +"Each bar represents the number of" +"individuals at each trophic level in the food" +"chain. At each link in a food chain, from" +"the first-order consumers to the large" +"" +"" +"" +"" +"NG" +"carnivores, there is normally an increase" +"in size, but decrease in number. Let us" +"observe fig-5, for example in a forest, the fig-5: Pyramid of numbers" +"" +"aphids are very small and occur in astronomical numbers, the ladybirds" +"which feed on them are distinctly larger and not so numerous, the" +"LA" +"insectivorous birds which feed on the ladybirds are larger still and are" +"only present in small numbers, and there may only be a single pair of hawks" +"of much larger size than the insectivorous birds on which they prey. This" +"relationship is best shown as a pyramid, which is upright." +"TE" +"" +"Draw the pyramid of number for the following food chains" +"" +"(i) Banyan tree insects Woodpecker" +"W" +"" +"(ii) Grass rabbit wolf" +"" +"Do the pyramid of numbers have the same structure in both the" +"T" +"" +"" +"cases when compared to the example given in the previous para-" +"graph?" +"ER" +"" +"" +"" +"" +"If there is a difference then what is it?" +"Sometimes the pyramid of numbers does not look like a pyramid at" +"all. This could happen if the producer is a large plant such as tree or if one" +"of the organisms at any trophic level is very small. So keep one thing" +"always in mind that whatever be the situation, the producers will be at the" +"SC" +"" +"" +"" +"" +"bottom of the pyramid." +"Pyramid of Biomass" +"What is biomass?" +"Biomass is organic material of biological origin that is ultimately" +"derived from the fixation of carbon dioxide by trapping solar energy during" +"photosynthesis. This includes trees, shrubs, crops, grasses, algae, aquatic" +"Free distribution by T.S. Government 2019-20 197" +" plants, agricultural and forest residues and all forms of human, animal" +"Secondary consumers" +"(Fish and otherand plant waste. Any type of plant or animal material that can be" +"aquatic animals)" +"converted into energy is called biomass. When these materials are" +"" +"" +"" +"" +"A" +"Primary" +"consumers" +"(Insects) used for energy production. They are known as biofuels." +"Producers" +"(Algae) The pyramid of biomass represents the relationships that exist" +"" +"" +"" +"" +"AN" +"between the quantity of living matter (biomass) at different trophic" +"fig-6: levels. In terrestrial ecosystems, the biomass progressively" +"Pyramid of decreases from producers to top carnivores." +"Biomass Are the pyramids always upright?" +"(pond) In an aquatic ecosystem, the biomass of phytoplankton is quite" +"" +"" +"" +"" +"NG" +"negligible as compared to that of the crustaceans and small" +"herbivorous fish that feed on these producers. The biomass of large" +"carnivorous fish living on small fishes is still greater. This makes the" +"pyramid of biomass inverted. It is found that 10 - 20 % of the biomass is" +"transferred from one tropic level to the next in a food chain." +"LA" +"A more accurate idea of food relationship may be obtained if the above" +"pyramid of numbers is converted into a pyramid of biomass. This indicates" +"the mass of plant matter which is used by the aphids to produce the mass" +"of the of aphids population, the total mass of the ladybird population that" +"TE" +"" +"could be supported by the aphids and so on through out the chain. In short" +"we can say that biomass is food for the next trophic level in a food chain." +"" +"Do you know?" +"To reduce our dependence on fossil fuels (fuels formed by natural processes such" +"T" +"" +"" +"as anaerobic decomposition of buried dead organisms, like coal, petrol etc.), and to" +"help reduce air pollution, biomass can also be used as a source energy. Using biomass" +"as fuel still puts carbon dioxide back into the atmosphere, but it is the same carbon" +"ER" +"" +"" +"" +"" +"dioxide taken from the air as the biomass was produced." +"" +"The biomass in a trophic level may be more or less than the other" +"trophic levels. Biomass is a measure of the amount of food available. When" +"animals eat, only a small proportion of their food is converted into new" +"SC" +"" +"" +"" +"" +"tissue, which inturn forms the food for the next trophic level. Most of the" +"biomass that animals eat is either not digested, or used to provide the" +"energy needed for staying alive." +"The biomass pyramid shows that animals are relatively inefficient in" +"converting food into body tissues, the remaining part of the food being" +"undigested is passed out as waste, or broken down in respiration to supply" +"" +"198 X Class Our environment - Our concern" +" energy for activities such as feeding. Many animals convert not more than" +"10% of their food into their body tissues, in some herbivores, it is even" +"less. Let us take an example of a food chain which has been worked out in" +"" +"" +"" +"" +"A" +"some detail- one in which we are involved when we eat fish. In this chain" +"the plant plankton on the surface of waters of sea are food producers." +"" +"" +"" +"" +"AN" +"They trap energy from sunlight. The animal plankton feed on the" +"microscopic plants and the fish in turn feed on the animal plankton; we are" +"at the end of the chain when we eat the fish." +"Pyramid of Energy" +"Food is the source of energy for organisms" +"" +"" +"" +"" +"NG" +"that are used in the growth and rebuilding the parts" +"of the body; that are constantly wearing out. The" +"food by its nature is the chemical energy and as" +"in stored form, it is the potential energy. There" +"are several mechanisms in organisms for" +"LA" +"continuous absorption of materials for the" +"production of organic material, and for the release" +"and conversion of organic material into inorganic" +"form. Plants absorb the minerals from the soil. fig-7: Pyramid of Energy" +"They are absorbed into the plant through roots." +"TE" +"" +"Photosynthesis is an essential process for the life. The energy in" +"sunlight, carbon dioxide and the water which are needed by all living things" +"belong to nonliving things. As a result of photosynthesis, these can be" +"made available in a suitable form of energy the food to the world of living" +"things the animals or consumers, only by the green plants the producers." +"T" +"" +"" +"The food chains and food webs help in the transfer of the food and energy" +"from the producers to different consumers. Animals obtain the minerals" +"ER" +"" +"" +"" +"" +"from the plant or animal food or both. Thus the mineral matter is constantly" +"being removed from the earth to become a part of the plant, which may" +"become a part of animal body." +"Try to identify the basic sources of various foods we eat. For example" +"curd that we eat is processed from milk, which comes from a cow, which" +"SC" +"" +"" +"" +"" +"in turn eats grass. The grass carries out photosynthesis and prepares food." +"In every case, the origin of food materials can be traced back to green" +"plants." +"Once the food is eaten, its energy follows a variety of pattern through" +"the organisms. Not all the food can be fully digested and assimilated. Hair," +"feathers, insect exoskeletons, cartilage and bone in animal foods, cellulose" +"and lignin in plant foods cannot be digested by most animals. These" +"Free distribution by T.S. Government 2019-20 199" +" materials are either ejected by defecation or regurgitated in pellets of" +"indigested remains." +"Assimilated energy (that is not lost through respiration or excretion)" +"" +"" +"" +"" +"A" +"is available for the synthesis of new biomass through growth and" +"reproduction. Organisms lose some biomass by death, disease or annual" +"" +"" +"" +"" +"AN" +"leaf-drop, where they enter the detritus pathways of the food chain i.e.," +"after the death and decomposition of organisms the materials flow back" +"into the environment. The remaining biomass is eventually consumed by" +"herbivores or predators and its energy there by enters the next higher trophic" +"level in the ecosystem." +"" +"" +"" +"" +"NG" +"Solar energy Producers (Chemical energy) Consumers (Chemical energy)" +"" +"Heat" +"LA Heat" +"" +"The materials keep on cycling i.e. entering the living beings and through" +"death and decay returning to the soil and atmosphere Such a flow of" +"materials between organisms and their environment is called Cycling of" +"materials or mineral circulation or Biogeochemical cycles (You have" +"learnt in class IX )." +"TE" +"" +"Energy enters the producers in the ecosystem from the sun in the form" +"of solar energy or solar radiation. No other organisms except green plants" +"and Photosynthetic bacteria due to the presence of chlorophyll are capable" +"of absorbing solar energy and converting it into chemical energy (food)." +"T" +"" +"" +"From the producers, the chemical energy passes to the consumers" +"from one tropic level to the next through food. At each trophic level," +"organisms use most of the food energy that they assimilate into their bodies" +"ER" +"" +"" +"" +"" +"to fulfill their metabolic requirements- performance of work, growth and" +"reproduction. Because biological energy transformations are inefficient," +"a substantial proportion of metabolized food energy is lost, unused as" +"heat. Hence pyramid of energy is always upright." +"SC" +"" +"" +"" +"" +"Only a small fraction goes to the eater at next trophic level. Organisms" +"are no different from man-made machines in this respect. Most of the" +"energy in gasoline is lost as heat in a car’s engine rather than being" +"transformed into the energy of motion. In natural communities, energy" +"used to perform work or dissipated as heat cannot be consumed by other" +"organism and is forever lost to the ecosystem." +"" +"" +"200 X Class Our environment - Our concern" +" The effects of human activities on ecosystems" +"In the earlier classes we have studied about different types of pollution" +"" +"" +"" +"" +"A" +"as a result of human interventions in ecosystem. In this section we will try" +"to understand that when we cut forest to grow food crops, how this activity" +"" +"" +"" +"" +"AN" +"brings harmful changes in ecosystem and affects organisms of each trophic" +"level." +"Let us study a pond ecosystem to understand the components of" +"environment, their interactions and effects of human interventions in the" +"" +"" +"" +"" +"NG" +"following story." +"Story of Kolleru Lake" +"Fresh water lakes provide the nutritional requirements of the world’s" +"poorest people. One such lake is Kolleru which is no ordinary wetland. It" +"is one of the largest fresh water lakes in India, existing between West" +"LA" +"Godavari and Krishna districts of the state of Andhra Pradesh. The" +"catchment of the lake extends up to 6121 km2. The lake Kolleru discharges" +"its excess water in to the Bay of Bengal through the twisty channel called" +"Upputeru, which is about 65 km long. Nevertheless, the Kolleru wetland" +"TE" +"" +"receives huge quantity of nutrient rich sediments from the flood plains of" +"these rivers." +"In November 1999, the Government of India had declared the lake as" +"Bird Sanctuary. This lake is hosting 193 species of birds and a variety of" +"T" +"" +"" +"flora and fauna, including medicinal plants. It attracts migratory birds from" +"northern Asia and Eastern Europe between the months of October and" +"ER" +"" +"" +"" +"" +"March and it is estimated as 20,00,000 birds per year. The lake was also an" +"important habitat for an estimated" +"20 million residents. This largest" +"sweet water lake has not only" +"shrunk in size but faced great threat" +"SC" +"" +"" +"" +"" +"due to pollution in the last three" +"decades as revealed by satellite" +"pictures. The decrease in water area" +"and muddy ground in the lake" +"resulted in flooding problems in the" +"fig-7: Kolleru Lake" +"lake area.." +"Free distribution by T.S. Government 2019-20 201" +" Observe the data given in the following table." +"" +"Table-1" +"" +"" +"" +"" +"A" +"Cuases Area in 1967 Area in 2004" +"(Km2) (Km2)" +"" +"" +"" +"" +"AN" +"Lake –water spread area 70.70 62.65" +"Lake with sparse weed 0 47.45" +"Lake with dense weed 0 15.20" +"Lake-liable to flood in rainy season 100.97 0" +"" +"" +"" +"" +"NG" +"Aquaculture ponds 0 99.74" +"Rice fields 8.40 16.62" +"Enchrochment 0.31 1.37" +"Total 180.38 180.38" +"LA" +"In which year lake-water spread area is more? Why?" +"Why do you think weeds are more dense in the lake?" +"What are the reasons for decrease in lake area?" +"How do the above said reasons lead to pollution?" +"What could be the reason for the migration of birds to this lake?" +"TE" +"" +"How was the threat to the lake due to pollution discovered?" +"Being a profitable business, Aquaculture in Kolleru was started" +"extensively in the eighties which later spread to other areas in the Krishna" +"Godavari delta and attracted a large number of investors to the area. In" +"1996, almost entire lake was brought under cultivation and bunds were" +"constructed to keep water out to protect the crops. This diversion affected" +"T" +"" +"" +"" +"the natural flow system of the lake. The water holding capacity of the lake" +"is also found significantly reduced." +"ER" +"" +"" +"" +"" +"In due course of time activities such as agriculture and industries came" +"along in ever growing intensity in the catchment area of the lake. Consequently," +"the drains and rivulets carry substantial quantity of various types of pollutants" +"into the lake. The major sources of pollution are agricultural runoff" +"containing residues of several agrochemicals, fertilizers, fish tank discharges" +"industrial effluents containing chemical residues and different types of" +"SC" +"" +"" +"" +"" +"organic substances, municipal and domestic sewage. Excessive nutrient" +"addition, especially from anthropogenic sources, led to explosive weed" +"growth. Ex: Eichhornia, Pistia (Eutrophication)." +"As a result, the water of the lake turned more alkaline in nature, turbid," +"nutrient rich, low in Dissolved Oxygen (DO) and high in Biological Oxygen" +"Demand (BOD). Which had great effect on aquatic animals. Water borne" +"diseases like diarrhoea, typhoid, amoebiasis and others are said to be" +"" +"202 X Class Our environment - Our concern" +" common among the local inhabitants who are unaware of the state of" +"pollution in the lake water. Vector borne diseases also increased. Prawn" +"and fish have been found to be affected by diseases leading to some farms" +"" +"" +"" +"" +"A" +"being abandoned. The lands thus abandoned are useless for agriculture too." +"The lake at present is prone to siltation, enchroachment, blockages in" +"canals. Due to aquaculture, 15 local varieties of fishes are endangered. As" +"" +"" +"" +"" +"AN" +"oxygen dissolution in water is decreasing, the number of fishes living in" +"surface water is increased." +"Let us observe the following table showing different activities in" +"the lake and their influence." +"Table-2" +"" +"" +"" +"" +"NG" +"Problem Agricultural Aquaculture Industrial Human" +"Practices practices activities aactivities" +"Biological" +"1. Decreased" +"- + - -" +"Migratory birds" +"LA" +"2. Population loss of - + - -" +"flora and fauna" +"3. Pathogens - - - +" +"TE" +"" +"Chemical" +"1. Eutrophication + + - +" +"2. Toxic contamination + + + -" +"Physical" +"1. Siltation + + - -" +"T" +"" +"" +"" +"2. Flooding + + - +" +"Legend: (+) means has influence on the mentioned problem" +"ER" +"" +"" +"" +"" +"(-) means has no influence on the mentioned problem" +"What are the factors that affected the number of migratory birds to" +"decrease?" +"Do you find any relationship between biological and physical" +"problems? What are they?" +"SC" +"" +"" +"" +"" +"What are the reasons for chemical problems?" +"What happens if the dissolved oxygen reduce in lake water?" +"Is BOD of turbid and nutrient rich water high or low? What are it’s" +"consequences?" +"People living in catchment area of Kolleru faced so many" +"problems. Why?" +"How does polution influence the migration of birds?" +"" +"Free distribution by T.S. Government 2019-20 203" +" The Ministry of Environment and Forest (MoEF), Government of India" +"constituted a committee “Operation Kolleru” to protect the lake. The" +"objective of the programme is to bring back the ecological balance of" +"" +"" +"" +"" +"A" +"Kolleru Lake which is a Gift of nature." +"Activity-1" +"" +"" +"" +"" +"AN" +"Observe any (water) ecosystem in your surroundings and identify the" +"different food chains and food web operating in this ecosystem. Write the" +"following details in your notebook." +"Work Sheet" +"" +"" +"" +"" +"NG" +"1. Names of the students in a group: _____________________ Date: _____________" +"2. Name of the ecosystem: _____________________________________________" +"3. Topography: ______________________________________________________" +"4. Names / Number of plants (producers) identified: _________________________" +"LA" +"5. Names / Number of animals identified: __________________________________" +"6. Identify the different types consumers and name them & mention their number below:" +"Herbivores (Primary consumers): ___________________________________" +"Carnivores (Secondary consumers): __________________________________" +"TE" +"" +"Top carnivores(Tertiary): _________________________________________" +"7. Food relationships among them: food habits / preferences: ___________________" +"8. Show / draw the different food chains: __________________________________" +"9. Showcase the food web: _____________________________________________" +"10. List out all abiotic factors existing in the ecosystem: ______________________" +"T" +"" +"" +"" +"( A check list can be given, and asked to tick)" +"11. Is there any threat to the ecosystem? Yes/No _____________________________" +"ER" +"" +"" +"" +"" +"If yes, what? and how? _____________________________________________" +"Suggest few remedial measures _______________________________________" +"" +"When a forest is cut down and a food crop is grown in its place, a" +"SC" +"" +"" +"" +"" +"natural established ecosystem with its vast number of species in a state of" +"dynamic equilibrium is replaced by a monoculture i.e. an unnatural" +"concentration of a single crop of various kinds grown in different fields" +"to provide cereals or roots, others grass for domestic animals." +"When we grow crops in large concentrations we also get food in" +"abundant quantities. This situation is optimum for pest, parasites like fungi" +"to grow on this food material. If the quantities of food are larger then" +"204 X Class Our environment - Our concern" +" multiplication of pests and parasites is rapid and the resulting damage would" +"be great. To avoid such happening we have tried to eliminate these" +"competitors for the crops by using toxic chemicals (pesticides, herbicides," +"" +"" +"" +"" +"A" +"and fungicides). Many of them have been very effective, but their use has" +"also created new problems." +"" +"" +"" +"" +"AN" +"The perfect pesticide is the one which destroys a particular pest and is" +"completely harmless to each and every other form of life, no such pesticide" +"exists or likely to be." +"Name any two pesticides/insecticides you have heard about?" +"How are the food grains and cereals being stored in your house" +"" +"" +"" +"" +"NG" +"and how do you protected them from pests and fungus?" +"Pesticides are often indiscriminate in their action and vast number of" +"other animals may be destroyed. Some of these may be predators which" +"naturally feed on these pests, others may be the prey for other animals." +"Thus causing unpredictable changes in food chains and upsetting the balance" +"within the ecosystem." +"LA" +"A further danger is that some have a cumulative effect. Pesticides vary" +"in their length of “life” as toxic substances. Some of the pesticides as well" +"as herbicides are degradable. They are broken down into harmless" +"TE" +"" +"substances in a comparatively short time, usually a year. Others are non" +"degradable, and include those which contain mercury, arsenic or lead. These" +"non degradable pesticides are potentially dangerous as they accumulate in" +"the bodies of animals and pass right through food web. Being further" +"concentrated at each step until animals at the top of pyramid may receive" +"enough to do considerable harm. The process of entry of pollutants into a" +"T" +"" +"" +"" +"food chain is known as Bioaccumulation, whereas the tendency of" +"pollutants to concentrate as they move from one trophic level to the next" +"ER" +"" +"" +"" +"" +"is known as Biomagnification." +"Let us observe the following research study on the effects of" +"bioaccumulation on human health." +"Seasonal Bioaccumulation of heavy metals in fish (cyprinus carpio)" +"of Edulabad Water Reservoir (EBWR)" +"SC" +"" +"" +"" +"" +"The aquatic bodies such as water reservoirs and rivers surrounding the" +"urban areas in India, pose a serious risk for survival of aquatic organisms" +"due to water quality deterioration through excessive nutrient inputs," +"acidification, heavy metal contamination and organic pollution." +"The aquatic biota is being contaminated with heavy metals due to" +"industrialization and anthropogenic activities." +"Free distribution by T.S. Government 2019-20 205" +" Recently, fish are considered to be the" +"bioindicators of metal contamination in" +"environmental monitoring because fish" +"" +"" +"" +"" +"A" +"species are strongly respond to stress" +"conditions." +"" +"" +"" +"" +"AN" +"A study was undertaken to assess the" +"enrichment of heavy metal such as Lead (Pb)," +"Cadmium (Cd), Chromium (Cr), Manganese" +"(Mn), Nickel (Ni) and Ferrum (Fe)" +"fig-8: Edulabad Water Reservoir" +"contamination in Edulabad Water Reservoir" +"" +"" +"" +"" +"NG" +"(EBWR) which is located in Medchal district of Telangana state, highly" +"polluted with industrial effluents. Cyprinus carpio (common scale carp)" +"is a cheap and high proteinaceous fish used as food for human beings," +"living in polluted EBWR was chosen for the study. Heavy metals in water" +"samples and its bioaccumulation in various tissues including liver, kidney" +"LA" +"and gill of the fish growing in the reservoir were analyzed along with" +"glycogen and lipids contents. A parallel study was conducted in water" +"samples and fishes collected from Bibinagar, Yadadri-Bhuvanagiri district" +"fresh water reservoir because it is less polluted, located 30 km from" +"EBWR. The results obtained in present study revealed that the" +"TE" +"" +"bioaccumulation is higher and the glycogen and lipid contents are lower" +"in the fish of EBWR when compared to Bibinagar fresh water reservoir." +"The water and fish samples were collected in three seasons namely" +"pre-monsoon (February-May), monsoon (June-September) and post" +"monsoon (October-January) in each year. Three water samples were" +"T" +"" +"" +"collected in three stations, thrice in each season from each tank in cleaned" +"polythene bottles. These are tightly stoppered and used for heavy metal" +"ER" +"" +"" +"" +"" +"analysis from June 2005 to May 2007." +"The metal concentrations in EBWR reservoir were found to be higher" +"than Indian standard limits and exhibiting the following sequence," +"Fe > Pb > Cr > Ni > Cd." +"The heavy metals could find their way into the human food chain, we" +"SC" +"" +"" +"" +"" +"analyzed bioaccumulation of these metals in the fish tissues. The" +"bioaccumulation of these metals in fish tissues were of the following trend," +"Cd > Cr > Fe > Ni > Pb." +"Higher bioaccumulation factors were found for Cd in liver, gill and" +"kidney indicated the sensitivity of fish to this metal even at low" +"concentrations." +"" +"206 X Class Our environment - Our concern" +" It is found that the bioaccumulation was lesser in monsoon season" +"than pre and post monsoon seasons." +"The heavy metals could find their way into human beings through food" +"" +"" +"" +"" +"A" +"chain. This bioaccumulation cause various physiological disorders such" +"as hypertension, sporadic fever, renal damage, nausea, etc." +"" +"" +"" +"" +"AN" +"It is concluded that unplanned urban settlements, combined with the" +"proliferation of unorganized small-scale industries and the sewage lead to" +"the contamination of the EBWR. Such increased bioaccumulation of heavy" +"metals in fishes not only disturbs aquatic life but also increases health" +"risk in human beings through food chain." +"" +"" +"" +"" +"NG" +"Where do the pollutants enter the water sources from?" +"How do heavy metals enter the fishes living in this water?" +"Researchers found that pollution levels increase during monsoon" +"season. Why they found so?" +"Why did people living in the areas near by the water reservoir, suf-" +"LA" +"fer from various diseases?" +"In many areas man has changed the natural ecosystems to a great extent" +"by damming rivers, draining marshes, re-claiming land from the sea, cutting" +"down forests, plough-ing up land and growing crops, and by building towns," +"TE" +"" +"cities, canals and motorways. These changes have greatly altered the" +"communities of plants and animals living there." +"Consider the development of a large town, for example. There will be" +"three kinds of change:" +"a) Some plants and animal species will die out." +"T" +"" +"" +"b) Some will adapt to the new conditions sufficiently to survive in re-" +"duced numbers." +"ER" +"" +"" +"" +"" +"c) Some will benefit by the new conditions and will increase in numbers." +"" +"" +"Do you know?" +"Minamata disease was first discovered in Minamata city in Kumamoto prefecture," +"SC" +"" +"" +"" +"" +"Japan, in 1956. It was caused by the release of methyl mercury in the industrial" +"wastewater from the Chisso corporation’s chemical factory, which continued from" +"1932 to 1968. This highly toxic chemical bioaccumulated in shellfish and fish in" +"Minimata Bay and the Shiranui Sea, which, when eaten by the local population, resulted" +"in mercury poisoning. While cat, dog, pig and humans deaths continued for 36 years." +"Let us read the following story to know how cruel the human actvities" +"are against the nature." +"Free distribution by T.S. Government 2019-20 207" +" Sparrow campaign" +"Any living organism can’t avoid crises since they are a normal part" +"" +"" +"" +"" +"A" +"of life. However, none have ever encountered a disaster on the level of" +"that which fell upon the Chinese Sparrows in 1958. The" +"environmental crisis in question was not a natural one" +"" +"" +"" +"" +"AN" +"rather, it was manmade. In the entire history of" +"sparrows around the world, they have never been" +"hunted down as they were in China in 1958." +"A radical campaign to rapidly increase China’s" +"industrial output by mobilizing the country’s vast rural" +"" +"" +"" +"" +"NG" +"fig-9: Sparrow in danger" +"peasantry took place at this time. It was set in motion" +"by the government with the intention to achieve rapid increase" +"in industrial production that China would catch up with the rest of the" +"civilized world. China had an agrarian society then." +"One of the most famous initiatives then was to form co-operatives" +"LA" +"or collectives up to 5,000 families and this initially yielded double the" +"amount of crops grown. This initial success led to ambitious goals for" +"the following year, but the weather didn’t cooperate. Even though fewer" +"crops were harvested, rural officials overstated the" +"TE" +"" +"amount of grain for fear of not meeting their" +"quotas. This over-reporting led to an imbalance" +"between the demand and the supply. The sparrows" +"were accused of pecking away at the supplies in" +"warehouses at an officially estimated rate of four" +"T" +"" +"" +"pounds of grain per sparrow per year. In the cities" +"and the outskirts, almost half of the labour force" +"was mobilized into the anti-sparrow army." +"ER" +"" +"" +"" +"" +"fig-10: Sparrow campaign" +"People started trapping, poisoning and killing sparrows in large" +"numbers. Several free-fire zones were set up for shooting the sparrows." +"People would beat drums to scare the birds from landing, so the" +"sparrows were forced to keep flying until they dropped dead from fatigue." +"SC" +"" +"" +"" +"" +"Sparrow nests were torn down, eggs were broken, and nestlings were" +"killed. Non-material rewards and recognition were offered to schools," +"work units and government agencies in accordance with the number of" +"sparrows killed." +"Later some scientists who cut open the digestive systems of dead" +"sparrows found that three-fourth of the contents were of insects harmful" +"for crops and only one-fourth contained grains. The scientific findings" +"208 X Class Our environment - Our concern" +" showed that sparrows were basically a beneficial bird for humans." +"Rather than being increased, crop yields after the campaign were" +"substantially decreased. Though the campaign against sparrows ended" +"" +"" +"" +"" +"A" +"it was too late. With no sparrows to eat the locust populations, the" +"country was soon swarmed. Locusts coupled with bad weather led to" +"" +"" +"" +"" +"AN" +"the Great Chinese Famine. Use of pesticides against locust population" +"further degraded the land." +"Instead of working in the fields, millions of farmers had to leave" +"their villages to work for industries. Very small area was left under" +"agriculture and food shortages became everyday occurrence." +"What is the food chain that has been discussed in the above case?" +"" +"" +"" +"" +"NG" +"How did the campaign disturb the food chain in the fields?" +"How did these disturbances affect the environment?" +"Is it right to eradicate a living organism in an ecosystem ?How is it" +"harmful?" +"Were the sparrows really responsible? What was the reason for the" +"fall in crop production?" +"LA" +"What did scientists find? Did they help in rectifying/correcting the" +"mistake? Why didn’t they do it so?" +"What was the impact of human activities on the environment?" +"What do you suggest to stop/avoid such incidents?" +"TE" +"" +"Read the poem “Manavi” in class VIII biology textbook and discuss" +"in your class, the reasons for the sparrows and the other birds from being" +"endangered in our surroundings." +"Steps towards prevention" +"If we think about the ways through which we can prevent ourselves and" +"other living beings from the harmful effects of the use of toxic material" +"T" +"" +"" +"" +"as pesticides, then the instant reaction may be to Ban the pesticides. It is" +"easy to say “Ban all pesticides” but the pests still have to be kept in check." +"ER" +"" +"" +"" +"" +"After using pesticides then also we are having a significant amount of loss" +"of food material because of pests. Now you can imagine if pesticides were" +"totally banned what would happen to the diseases? Are they really" +"controlling the pests that effect the crops we vitally need for our growing" +"population?" +"SC" +"" +"" +"" +"" +"The long term solution to this problem is to find other effective" +"methods of controlling pests which have far less harmful effects and are" +"based on sound biological principles." +"Here are some of the important methods to be used." +"Rotation of crops: Growing different crops on a particular piece of land" +"in successive years reduces the occurence of pests and damage to the" +"crops from year to year in that area." +"Free distribution by T.S. Government 2019-20 209" +" Studying the life histories of the pests: By understanding how the pests" +"spread and its stages in life history, the seeds can be sown at that time to" +"reduce the damage to the crop." +"" +"" +"" +"" +"A" +"Biological control: Introducing natural predators or parasites of the pests." +"Sterility :Rendering the males of a pest species sterile" +"" +"" +"" +"" +"AN" +"Genetic strains: The development of genetic strains (genetically modified" +"plants) which are resistant to certain pest." +"Environmental ethics: This is concerned with morality of human activities" +"as they affect the environment. People need to know besides laws regarding" +"environment there are some basic ethics what is right and what is wrong in" +"view of environment." +"" +"" +"" +"" +"NG" +"So one should have awareness about our environment. Protect nature" +"Protect yourselves.Read the poem “Or will the dreamer wake” given in" +"unit-VI in your english reader of class-10." +"" +"Courtesy-1: Research paper on status of Kolleru Lake between 1967 and 2004 by Marappan et.al., 2006." +"Courtesy-2: International Jornal of Life Sciences Biotechnology and Pharma Research. This research was" +"LA" +"done by Vidya Sagar Gummadavelli, Ravi Shankar Piska, Srinu Noothi and Pavan K. Manikonda." +"" +"" +"Key words" +"Food chain, Food web, Niche, Ecological Pyramid, Biomass, Pesticides," +"TE" +"" +"Bioaccumulation, Biomagnification, Ecofriendly activities, Environmental ethics, metal" +"contamination." +"" +"" +"What we have learnt" +"T" +"" +"" +"" +"Food chain shows that how energy passes from one organism to another." +"ER" +"" +"" +"" +"" +"The arrows between different trophic levels in the food chain always point from the food to feeder." +"Ecological pyramids are the ways of showing food relationship and flow of energy among living" +"things." +"A pyramid is a structure whose shape is roughly that of a pyramid in geometric sense." +"Pyramid of numbers shows the population of organisms at each trophic level in a food chain." +"Pyramid of biomass represents the available food as a source of energy at each trophic level in the" +"SC" +"" +"" +"" +"" +"food chain." +"Biomass can also be used as a biofuel." +"Pyramid of energy is always upright." +"The pesticides used to control the pests are toxic and cause a threat to the environment." +"Bioaccumulation is the entry of pollutants into the food chain." +"The tendency of pollutants to concentrate as they move from one trophic level to the next is known" +"as Biomagnification." +"210 X Class Our environment - Our concern" +" There are several alternatives for pesticides, through which we can get more yield with less damage" +"such as rotation of crops, biological control, developing resistant strains etc." +"" +"Improve your learning" +"" +"" +"" +"" +"A" +"1. What happens to the amount of energy transferred from one trophic level to the next in a food" +"" +"" +"" +"" +"AN" +"chain?(AS1)" +"2. What do pyramids and food chain indicate in an ecosystem?(AS1)" +"3. Write a short note on pyramid of numbers for any food chain. What did you conclude from the" +"pyramid of numbers drawn using :" +"(i) tree (ii) insects (iii) woodpecker (AS1)" +"" +"" +"" +"" +"NG" +"4. Draw the pyramid of biomass using the terms given below:" +"(i) grass (ii) herbivores (iii) predators (iv) hawk (AS5)" +"5. How does the usage of toxics substances affect an ecosystem? Write a short note on bioaccumulation" +"and biomagnification. (AS1)" +"6. Should we use pesticides to protect the crops and foods from pests? Or should we think of" +"alternatives? Write your opinion and the reasons for it. (AS1)" +"LA" +"7. What is a trophic level? What does it represent in an ecological pyramid?(AS1)" +"8. If you want to know more about flow of energy in an ecosystem, what questions do you ask?(AS2)" +"9. What will happen if we remove predators from food web?(AS2)" +"10. Observe a plant in your kitchen garden, and write a note on producer- consumer relationship.(AS3)" +"TE" +"" +"11. Collect information on laws and ethics concerned to the environment and display it on bulletin" +"board. (AS4)" +"12. Draw a pyramid of numbers considering yourself as a top level consumer. Write about the lower" +"trophic levels. (AS5)" +"13. Prepare slogans to promote awareness in your classmates about ecofriendly activities.(AS7)" +"14. Suggest any three programmes on avoiding pesticides and preventing soil pollution.(AS7)" +"T" +"" +"" +"" +"Choose the correct answer" +"ER" +"" +"" +"" +"" +"1. What does a food chain always start with - ( )" +"(A) The herbivore (B) The carnivore (C) The producer (D) none of them" +"2. Which of the following do plants not compete for? ( )" +"(A) Water (B) Food (C) space (D) all above" +"SC" +"" +"" +"" +"" +"3. Ban all pesticides, this means that ( )" +"A) Control on usage of pesticides B) prevention of pesticides" +"C) promote ecofriendly agricultural practices D) stop biochemical factories" +"4. According to Charles Elton ( )" +"A) carnivores at the top of the pyramid" +"B) energy trapping is high at the top of the pyramid" +"C) No producers at the top of the pyramid" +"D) a and c" +"Free distribution by T.S. Government 2019-20 211" +" A" +"Chapter" +"" +"" +"" +"" +"AN" +"10" +"" +"" +"NG" +"Natural Resources" +"LA" +"We learnt about natural resources like water, soil, forests, flora, fauna" +"etc. and how to conserve them, in previous classes. We also learnt about" +"the pollution of natural resources as a result of human activities. Natural" +"resources are present in abundance, but do we really manage them properly?" +"We shall study about human interventions affecting them and efforts that" +"TE" +"" +"are being made to sustain and save them." +"Try to make a list of exhaustive natural resources in your locality. Try" +"to find out about a particular resource especially one that is scarce in" +"detail. Some questions below will help you to find out more about the" +"resources." +"T" +"" +"" +"Which resource in your locality is scarce? How does it affect you?" +"Was the resource present in abundance earlier?" +"ER" +"" +"" +"" +"" +"How did it become scarce over the years?" +"What can you do as a step towards saving a resource?" +"Let us study about two villages of Telangana State to make a study of" +"an important resource and see what happens when it becomes scarce." +"SC" +"" +"" +"" +"" +"Case I: Situation in two villages Wanaparthy and Vaddicherla" +"of Jangaon District" +"A survey was conducted in two villages,Wanaparthy and Vaddicherla" +"of Jangaon District of Telangana region -the first with no-scarcity (good)," +"and the second with scarce groundwater.Census of wells was carried out" +"in the villages in order to get a complete picture of well irrigation and its" +"status as well as availability of water. Basic information on irrigation under" +"212 X Class Natural Resource" +" wells was collected using a small questionnaire from all the well owners" +"in the sample villages." +"Detailed information regarding various socio-economic aspects was" +"" +"" +"" +"" +"A" +"collected using a detailed questionnaire from a sample of 25 households" +"owning wells. Families in both the villages were asked to narrate the changes" +"" +"" +"" +"" +"AN" +"in groundwater situation during the last five years." +"There are no alternative sources of water supply as against wells in" +"Vaddicherla, whereas there is an existing tank that has been converted into" +"a percolation tank, so that the water situation is much better in Wanaparthy." +"" +"" +"" +"" +"NG" +"Do you know" +"Percolation tanks are normally earthen dams" +"with masonry structures where water may overflow." +"Construction materials consist of a mixture of soil," +"silt, loam, clay, sand, gravel, suitably mixed and laid" +"LA" +"in layers at the base or bed and sides. It is properly" +"compacted to achieve stability. Outlets for surface" +"irrigation are made and a cut-off trench is made" +"below the earthen bund or dam with depth limited" +"to one fourth of the height between bed level and" +"TE" +"" +"Percolation tank" +"full storage level." +"" +"Basic features of the villages Wanaparthy and Vaddicherla are almost" +"similar in terms of occupational pattern, cropping pattern, geographical" +"factors, infrastructure and social services. In both the villages small farmers" +"are in majority. Wanaparthy has the higher average household income. The" +"T" +"" +"" +"" +"main livelihood activity in these villages is cultivation and the primary" +"source of irrigation is well. Household income is dependent on the status" +"ER" +"" +"" +"" +"" +"of groundwater. Wanaparthy has a higher proportion of its area under" +"irrigation. The cropping pattern which influences average household" +"income in these villages differs substantially." +"Though rain has not been consistent for a few years, farmers in these" +"villages prefer growing paddy. Observe the following table." +"SC" +"" +"" +"" +"" +"Table-1: Area under irrigation" +"Village T" +"Total Area (acres) Percentage Number of Sample Size" +"Area Irrigated Wells" +"Wanaparthy 3791 25 155 25" +"Vaddicherla 2970 15 175 25" +"" +"Free distribution by T.S. Government 2019-20 213" +" What is the total irrigated area in acres, in Wanaparthy?" +"If one needs to irrigate all the land in Vanaparthy, how many wells" +"would be required?" +"" +"" +"" +"" +"A" +"Though the number of wells is less in Wanaparthy, the area under" +"irrigation is more as compared to Vaddicherla. How is this possible?" +"" +"" +"" +"" +"AN" +"Do you think the area under irrigation will change due to increase" +"in population?" +"The change in area under cultivation, percentage change in number of" +"wells and cropping pattern in 5 years as narrated by the people has been" +"presented in table-2." +"" +"" +"" +"" +"NG" +"The population in the villages has also gone up in a period of 5 years" +"by nearly 10%." +"Table 2: Status after five years" +"Percentage Percentage Percentage change in" +"Village change in area decline in area under crops" +"LA" +"under irrigation number of wells Paddy Cotton Gingelly All Crops" +"K R K R" +"Wanaparthy -14 -39 -17 -17 163 86 11 -17" +"Vaddicherla -30 -68 -22 -50 27 138 -05 -50" +"TE" +"" +"K stands for Kharif while R stands for Rabi. Negative values indicate" +"loss/ decline, while positive ones show gain/rise." +"If the number of wells is 155 now, what was it 5 years back?" +"What does ‘decline in number of wells’ represents?" +"How would crops be affected due to decline in the number of wells?" +"T" +"" +"" +"" +"Compare table 1and2 and state what they tell us about the area" +"under irrigation in both the villages?" +"ER" +"" +"" +"" +"" +"Which village do you think is more affected?" +"What is the change in types of crops grown in the villages?" +"Of late, most of the open dug wells were converted into bore wells" +"that could reach greater depths of ground water zones and would also reduce" +"loss of water by surface evaporation.Most of the open wells have dried up" +"SC" +"" +"" +"" +"" +"and water tables have gone down substantially during the last 5 years. During" +"this time, 85 percent of the wells, mostly open, have dried-up in Vaddicherla" +"while 45 percent of the wells dried-up in Wanaparthy." +"If 45 percent of wells have dried up in Wanaparthy, and there is 39" +"percent decline in number of wells, what percentage of wells do you" +"think have been converted to bore wells?" +"" +"214 X Class Natural Resource" +" By comparing the two villages, find out in which village, greater" +"number of wells dried up? What methods would have saved the" +"wells in other village?" +"" +"" +"" +"" +"A" +"Which type of farmers, those having small land holdings or those" +"with large land holdings are most affected when wells dry up?" +"" +"" +"" +"" +"AN" +"If water resource becomes scarce, will it affect the nature of soil in" +"an area?" +"As wells dry up, how are people in the area dependent on the well" +"affected?" +"Why do you think water became scarce mainly in Vaddicherla?" +"" +"" +"" +"" +"NG" +"Water is usually pumped out of wells and bore wells using electricity." +"Farmers with small land holdings or small farmers tend to spend more" +"money per well in terms of installation of pump sets and pipeline" +"connections to farms(or capital expenditure) as well as running costs" +"towards maintenance, electric charges etc. On per acre basis, both capital" +"LA" +"and running costs are the lowest in Wanaparthy (no-scarcity village) and" +"highest in Vaddicherla (scarcity village)." +"Table 3: Annual expenditure on well irrigation for small and large farmers(2002)" +"Depth of bore" +"TE" +"" +"Type of Percentage area Total cost of well" +"Village Farmer well (in feet) irrigated per well irrigation per acre" +"Kharif Rabi per year in rupees" +"Wanaparthy Large 130 - 200 2.50 1.24 25000- 70000" +"Small 110 - 180 2.00 1.13 25000- 65000" +"T" +"" +"" +"Vaddicherla Large 90 - 300 1.53 0.87 22000- 50000" +"Small 60 - 200 0.99 0.46 20000- 45000" +"ER" +"" +"" +"" +"" +"Is the availability of water resource same for a small and a large farmer?" +"Do you think the availability should be same for everyone in an area?" +"A well irrigates more area in Kharif season as compared to Rabi, how is it possible?" +"How should a farmer utilize such a condition?" +"If a well can irrigate 2.5 percent of cultivable land, how many wells would irrigate" +"SC" +"" +"" +"" +"" +"whole of the land?" +"Which factor has a greater effect on expenditure, number of wells or depth of a well?" +"What is the total expenditure on a whole cultivable land owned by a small farmer in" +"Vaddicherla?How do you think a small farmer meets this expenditure?" +"What could help the small farmer reduce expenditure? (Hint: think of crops that" +"require less water)" +"Free distribution by T.S. Government 2019-20 215" +" Do you think increasing the depth of bore well is a good solution" +"for increasing total land area under irrigation? Why/Why not?" +"" +"" +"" +"" +"A" +"Do you know?" +"Because of varying monsoon behaviour in recent years, there is a pressure on" +"" +"" +"" +"" +"AN" +"groundwater utilization. Indiscriminate tapping of groundwater in the State by too" +"much drilling and construction of deep tube wells and bore wells, have resulted in" +"over exploitation and depletion of groundwater resources in certain areas. Average" +"fall of water level was around 3 meters in the State during the period of 1998- 2002." +"Let us analyse income of small and large type of farmers in Wanaparthy" +"" +"" +"" +"" +"NG" +"and Vaddicherla villages." +"Table 4: Income on crops" +"" +"Village Type of Net income per acre in Rupees Total income per" +"Farmer Paddy Paddy Cotton Gingelly acre year in rupees" +"Kharif Rabi" +"Wanaparthy Large" +"LA" +"8200 8700 4900 3300 25100" +"Small 7046 8490 10889 3110 29535" +"Vaddicherla Large 10698 5970 4000 3595 24263" +"Small 9128 7380 3031 2650 22189" +"TE" +"" +"Which crop is most profitable for a small farmer in Vaddicherla?" +"What is the difference between a small farmer in Wanaparthy and" +"Vaddicherla?" +"Which crop could replace paddy and be profitable as well for a" +"small farmer in Wanaparthy?" +"T" +"" +"" +"Though we know that paddy consumes maximum water, why do you" +"think farmers still like to grow paddy?" +"ER" +"" +"" +"" +"" +"What is the impact of a depleting resource upon the farmers?" +"Do you think the income of a small farmer in Vaddicherla is sufficient" +"enough to meet his expenditure?" +"What are the major causes of pitiable condition of small farmers at" +"Vaddicherla?" +"Do you think farming as an occupation is profitable for the small" +"SC" +"" +"" +"" +"" +"farmer in Vaddicherla?" +"Would the farmer have to look for other kind of occupations to meet" +"his needs?" +"How did the availability of water affect a small farmer at Vaddicherla?" +"A project of the Centre for world solidarity(Secundrabad, T.S.) that" +"addresses sustainability of ground water intervened to help in recharging" +"wells that were drying up in the villages." +"216 X Class Natural Resource" +" They encouraged more water sharing among farmers. They formed" +"groups of farmers including large and small ones who would use the same" +"water resource. Farmers were also motivated to use irrigation techniques" +"" +"" +"" +"" +"A" +"like drip irrigation, sprinklers etc.(collectively called as microirrigation" +"techniques). Construction of soak pits to tap rainwater optimally was carried" +"" +"" +"" +"" +"AN" +"out as community efforts. Soakpits helped in recharging dried up bore" +"wells. Dykes or barriers, nearly 30 cm thick of brick-cement or stone" +"cement barrier, extending down to the compact bedrock, with mud or clay" +"fillings were built in underground streams to tap ground water optimally." +"How can wells be recharged?" +"" +"" +"" +"" +"NG" +"How would recharging dried up wells help farmers of Vaddicherla?" +"What does the case tell us about a water resource and its effect on" +"farmers?" +"Water for all" +"Out of all the water on Earth, salt water in oceans, seas and saline" +"LA" +"groundwater make up about 97% of it. Only 2.5–2.75% is fresh water," +"including 1.75–2% frozen in glaciers, ice and snow(nearly two thirds of" +"the available freshwater), 0.7–0.8% as fresh groundwater and soil moisture," +"and less than 0.01% of it as surface water in lakes, swamps and rivers." +"Though it is a meagre portion of the whole, if used judiciously, shall last" +"TE" +"" +"for a long time." +"How do you think we can use water judiciously?" +"Why were farmers at Wanaparthy at a better state than those at" +"Vaddicherla?" +"How did farmers of Vaddicherla and Wanaparthy recharge their" +"T" +"" +"" +"ground water resources?" +"" +"Do you know?" +"ER" +"" +"" +"" +"" +"In ancient times, village boundaries were decided upon on a watershed(land between" +"water sources usually of two rivers or streams) basis fixed at the common point of" +"the drainage system in between two villages by the expert farmers in the village. Such" +"boundaries were socially acceptable to all the members of the system." +"SC" +"" +"" +"" +"" +"The development lies in the efficient usage of water resources. To" +"explain this fact we will observe the given case study." +"Case II: A Study of Kothapally Village, an example of water" +"management effort" +"This tells us how people in the village through proper guidance could" +"make optimum use of available water in the village." +"Free distribution by T.S. Government 2019-20 217" +" A survey of Kothapally village indicated that initially: (i) dry land areas" +"were more extensive than irrigated land; (ii) literacy was low; (iii) labour was" +"scarce; (iv) more fertilizers/pesticides were used on small farms (v) crop" +"" +"" +"" +"" +"A" +"yields were low, (vi) there was not even a single water harvesting structure in" +"the village. Let us observe the interventions done to enhance productivity and" +"" +"" +"" +"" +"AN" +"income (Soil and water conservation measures) in this village." +"International Crop Research Institute for Semi-Arid Tropics( ICRISAT)" +"educated villagers in large numbers and provided technical support for" +"cost-efficient water storage and soil conservation structures. The measures" +"were community as well as individual farmer-based. These helped to restore" +"" +"" +"" +"" +"NG" +"some resources and conserve others so that they may never be depleted." +"Thus sustainable management was carried out." +"What is ICRISAT, where is it? What are its functions? Discuss with" +"your teacher and prepare a report on it." +"Community-based interventions" +"LA" +"Fourteen water storage structures (one earthen and 13 masonry dams)" +"with water storage capacity of 300 to 2 000 m3were constructed. 60 mini-" +"percolation pits and field bunding on 38 hectares were completed." +"TE" +"T" +"ER" +"" +"" +"" +"" +"fig-1: Communitybased masonry dam fig-2: Contour field bunding" +"" +"Do you know?" +"Sri Rama Sagar Project also known as the Pochampadu Project is a project on the" +"Godavari River. It is a “lifeline for a large part of Telangana”. It is mainly an irrigation" +"project to serve needs in Karimnagar, Warangal, Adilabad, Nalgonda, and Khammam" +"SC" +"" +"" +"" +"" +"districts. But all is not well with the" +"project as most of the water is" +"retained before reaching Telangana" +"due to the dams built on river" +"Godavari in another State.As of" +"August 2013, the project has an" +"estimated capacity of 80.66 TMC. Sri ram sagar project" +"" +"218 X Class Natural Resource" +" Twenty-eight dry open wells, near nalla canal or the Lakshmi canal" +"(sourced from the Sri Rama Sagar project reservoir) were recharged by" +"building dykes or barriers in the nalla canal and retaining the runoff" +"" +"" +"" +"" +"A" +"rainwaterin it. A users group was formed for each water storage structure," +"and the water collected in the storage structures was exclusively used for" +"" +"" +"" +"" +"AN" +"recharging the groundwater to the dried wells." +"Farmer-based interventions" +"Farmer-based soil and water conservation measures implemented in" +"individual fields were broad bed furrow (BBF) landform and contour" +"" +"" +"" +"" +"NG" +"planting. These are all useful to conserve soil and water,fertilizer application" +"and weeding operations, field bunding of 38 hectare, around boundaries in" +"rectangular or in contours to conserve rain water. Planting Gliricidia" +"(Madri, a leguminous plant adapted to grow in dry areas) on field bunds to" +"strengthen them and make the soil nitrogen-rich.Farmers were encouraged" +"to use water resource jointly and irrigate land using micro irrigation" +"LA" +"techniques." +"TE" +"T" +"" +"" +"" +"fig-3: Broad bed furrow fig-4: Plantation of Gliricidia on bunds" +"ER" +"" +"" +"" +"" +"Farmers obtained 250 kg more pigeon pea and 50 kg more maize per" +"hectare using broad bed furrows and micro irrigation techniques." +"Drip irrigation (a type of micro irrigation) can reduce water" +"consumption by 70% but unfortunately only 2% of cultivable land around" +"the world is irrigated in this manner." +"SC" +"" +"" +"" +"" +"Wasteland development and tree plantation" +"Saplings of useful species were planted along the" +"roads, field bunds and nalas. Contour trenches at 10" +"m intervals with a 0.3 m height of bund were laid out." +"Custard apple plantation along with other useful" +"species in trenches and Gliricidia saplings on bunds fig-5: Tree plantation on wasteland" +"Free distribution by T.S. Government 2019-20 219" +" was undertaken by the farmers. 2500 fruit trees and teak plants were planted." +"What other ways of restoration of a resource does the Kothapally" +"case tell us about?" +"" +"" +"" +"" +"A" +"What are some common means of restoration and conservation of" +"water resource that we came across in the cases studied so far?" +"" +"" +"" +"" +"AN" +"According to a survey conducted in the year 2004" +"Total amount of water available in Telangana and Andhra Pradesh - 3814" +"thousand million cubic feet (TMC)" +"Total amount utilised - 2300 TMC of which" +"" +"" +"" +"" +"NG" +"Irrigation - 2268 TMC" +"Domestic use - 21 TMC" +"Industries - 10 TMC" +"Power generation - 1 TMC" +"Amount required for utilisation by 2025 is 3989TMC of which" +"LA" +"3,814TMC is for irrigation, 122TMC for domestic use, 51TMC for" +"industries and 2TMCis for power generation." +"What do you think will happen if we do not take care of the sources" +"of water?" +"TE" +"" +"How do you think we will meet our requirements in future?" +"Do you think we would have to depend upon other states or perhaps" +"other countries as well?" +"Could the amount of water used for irrigation in our state be" +"reduced? How?" +"Does cropping pattern have any role to play in reduction of water" +"T" +"" +"" +"" +"utilisation? (Hint:Think of the case of Vaddicherla and Wanaparthy)." +"Do you think one needs laws for distribution of water and its use?" +"ER" +"" +"" +"" +"" +"Why/Why not?" +"Source of irrigation water in Telangana and Andhra Pradesh" +"How much per cent of area do you think is irrigated by other sources" +"of water?" +"SC" +"" +"" +"" +"" +"We have seen that major consumption of water is in the farming sector." +"In spite of some major rivers like Godavari and Krishna, the major source" +"of irrigation is groundwater." +"Why is it important to recharge the ground water sources?" +"Why do the rivers fail to benefit the state to an extent they should" +"have?" +"" +"220 X Class Natural Resource" +" Since ground water Other sources 5%" +"resources are getting" +"Tanks 15%" +"depleted at a fast pace" +"" +"" +"" +"" +"A" +"Cannals 37%" +"what are the alternatives?" +"River Godavari fails to Ground water 43%" +"" +"" +"" +"" +"AN" +"provide water for the" +"projects like Sri Rama" +"Sagar in our State due to" +"over usage of water by" +"some other states." +"" +"" +"" +"" +"NG" +"How should states and fig-6:" +"countries work to provide Sources vs area under irrigation" +"enough for all?" +"It is comforting to think water is a renewable resource but we must" +"know what limitless exploitation of a resource can lead to. According to" +"LA" +"United Nations Development Programme, “Water resource in an area," +"where annual water supply drops below 1700 m3 per person, is becoming" +"scarce.” The food and Agriculture Organisation of the United Nations has" +"predicted that by 2025, 1.8 billion people will be living in countries or" +"TE" +"" +"regions with absolute water scarcity." +"Activity-1" +"Study the different ways in which water is used, misused and recycled" +"in the area where you stay. Prepare a questionnaire with the help of your" +"friends and teacher and study at least five households in your locality for" +"T" +"" +"" +"the same. Also explore and discuss ways to provide water for all." +"Natural resources around us" +"ER" +"" +"" +"" +"" +"The Earth’s natural resources include air, water, soil, minerals, fuels," +"plants, and animals. Conservation is the practice of caring for these" +"resources so all living things can benefit from them now and in the future." +"All the things we need to survive, such as food, water, air, and shelter," +"SC" +"" +"" +"" +"" +"come from natural resources. Some of these resources can be replaced" +"after they are used and are called renewable resources. Other resources," +"such as fossil fuels, cannot be replaced at all. Once they are used up, they" +"are gone forever. This is because it takes a long time for their formation" +"while their consumption occurs very quickly. These are nonrenewable" +"resources." +"People often waste natural resources. Animals are overhunted. Forests" +"Free distribution by T.S. Government 2019-20 221" +" are cleared, exposing land to wind and water damage. Fertile soil is" +"exhausted and lost to erosion because of poor farming practices. Fuel" +"supplies are depleted. Water and air are polluted." +"" +"" +"" +"" +"A" +"If resources are carelessly managed, many will be used up. If used" +"wisely and efficiently, however, renewable resources will last much longer." +"" +"" +"" +"" +"AN" +"Through conservation, people can reduce waste and manage natural" +"resources wisely." +"" +"Do you know?" +"Water use restrictions are implimented in many regions of the world. In Australia," +"" +"" +"" +"" +"NG" +"in response to chronic shortage resulting from drought, restrictions are imposed on" +"activities like, watering lawns by using sprinkler systems, washing vehicles, using hose" +"pipes to clean paved areas, and refilling swimming pools." +"The population of human beings has grown enormously in the past two" +"centuries. Billions of people use up resources quickly as they eat food," +"LA" +"build houses, produce goods and burn fuel for transportation and electricity." +"The continuation of life as we know depends on the careful use of natural" +"resources." +"The need to conserve resources often conflicts with other needs. For" +"TE" +"" +"some people, a forest area may be a good place to put a farm. A timber" +"company may want to harvest the area’s trees for construction materials." +"A business company may want to build a factory or shopping mall on the" +"land. All these needs are valid for us, but sometimes the plants and animals" +"that live in the area are forgotten. The benefits of development need to be" +"weighed against the harm to animals that may be forced to find new habitats," +"T" +"" +"" +"the depletion of resources we may want in the future (such as water or" +"timber), or damage to resources we use today." +"ER" +"" +"" +"" +"" +"Think of any resource from your surrounding other than water" +"that you cannot do without and write a short account on its" +"sources, availability and condition." +"Development and conservation can coexist in harmony. When" +"we use the environment in ways that ensure we have resources for" +"SC" +"" +"" +"" +"" +"the future, it is called sustainable development. There are many" +"different resources we need to manage and conserve and main order" +"to live sustainably." +"What would you do to motivate others to manage an" +"fig-7: Sustaibable important resource in your locality?" +"development" +"How did the villagers in Kothapally resort to sustainable" +"management?" +"222 X Class Natural Resource" +" Forest: an important renewable resource" +"Why do you think forests are important?" +"" +"" +"" +"" +"A" +"Every continent except Antarctica has forests. Which are rich habitat" +"for plants and animals. Forests serve as a lung for the world and a bed of" +"nutrients for new life to prosper. They provide us innumerable products" +"" +"" +"" +"" +"AN" +"and in an urge to extract them we indiscriminately destroy them." +"People clear forests to use the wood, or to make way for farming or" +"development. Each year, the Earth loses about 36 million acres of forest" +"to deforestation." +"Deforestation destroys wildlife habitats and increases soil erosion. It" +"" +"" +"" +"" +"NG" +"also releases greenhouse gases into the atmosphere, contributing to global" +"warming. Deforestation accounts for 15 percent of the world’s greenhouse" +"gas emissions. Deforestation also harms the people who rely on forests" +"for their survival, hunting and gathering, harvesting forest products, or using" +"the timber for firewood." +"LA" +"Sustainable forestry practices are critical for ensuring resources well" +"into the future. Perhaps the bishnoi’s of Rajasthan could tell us how. As" +"we recall brave Amrita Devi and her daughters, followed by villagers who" +"clung to trees in the forest surrounding their village and laid down their" +"lives to save them, we are faced with a realization about how great a" +"TE" +"" +"movement towards conservation can be. They were protesting against the" +"Kings’ order to collect wood for the construction of his palace and" +"defending the pledge of peaceful coexistence taken by them as a bishnoi." +"It is a set of 29 rules to conserve natures’ resources that every bishnoi" +"vows to protect." +"T" +"" +"" +"As you have already studied about the Chenchu and Gondu tribes of" +"our state and are aware of how carefully they extract resources from nature" +"and help revive it. (refer lesson of VII class - Forest our life)" +"ER" +"" +"" +"" +"" +"Some sustainable forestry methods include using low-impact logging" +"practices, harvesting with natural regeneration in mind, and avoiding certain" +"logging techniques, such as removing all the high-value trees or all the" +"largest trees from a forest." +"Trees can also be conserved if consumers recycle. People in China" +"SC" +"" +"" +"" +"" +"and Mexico, for example, reuse much of their wastepaper, including writing" +"paper, wrapping paper, and cardboard. If half the world’s paper were" +"recycled, much of the worldwide demand for new paper would be fulfilled," +"saving many of the Earth’s trees. We can also replace some wood products" +"with alternatives like bamboo, which is actually a type of grass, that grows" +"very fast." +"" +"Free distribution by T.S. Government 2019-20 223" +" Soil" +"Soil is vital to food production. We need high-quality soil to grow the" +"" +"" +"" +"" +"A" +"crops that we need. Soil is also important to plants that grow in the wild." +"Many other types of conservation efforts, such as plant conservation and" +"animal conservation, depend on soil conservation." +"" +"" +"" +"" +"AN" +"Poor farming methods, such as repeatedly planting the same type of" +"crop in the same place, deplete nutrients in the soil. Soil erosion by water" +"and wind increases when farmers plough up and down hills." +"One soil conservation method is called contour strip cropping. Several" +"crops, such as corn, wheat, and clover, are planted in alternating strips" +"" +"" +"" +"" +"NG" +"across a slope or across the path of the prevailing wind. Different crops," +"with different root systems and leaves, help to prevent soil erosion." +"Selective harvesting methods means we harvest mature commertial trees" +"of a specific diameter on a rotational cycle to maintain the forest Eco-" +"balance. Harvested areas are then closed for a prescribed period of time" +"before the next harvest cycle in the same area. This provides younger trees" +"LA" +"a chance to grow full commertial potential while removing aged tress that" +"would otherwise die naturally allowing forest to regenerate naturally." +"Biodiversity" +"Biodiversity is the variety of living things that populate the Earth. The" +"TE" +"" +"products and benefits we get from nature rely on biodiversity. We need a" +"rich mixture of living things to provide foods, building materials, and" +"medicines, as well as to maintain a clean and healthy landscape." +"When a species becomes extinct, it is lost to the world forever." +"Scientists estimate that the current rate of extinction is 1,000 times the" +"natural rate. Through hunting, pollution, habitat destruction, people are" +"T" +"" +"" +"speeding up the loss of biodiversity at an alarming rate. It’s hard to know" +"how many species are going extinct because the total number of species" +"is unknown. Scientists discover thousands of new species every year. For" +"ER" +"" +"" +"" +"" +"example, after looking at just 19 trees in Panama, scientists found 1,200" +"different species of beetles 80 percent of them unknown to science at the" +"time. Based on various estimates of the number of species on Earth, we" +"could be losing anywhere from 200 to 100,000 species each year." +"We need to protect biodiversity to ensure plentiful and varied food" +"SC" +"" +"" +"" +"" +"sources." +"Biodiversity is more important than food. For instance, we use between" +"50,000 to 70,000 plant species for medicines worldwide." +"A lawn in a colony is usually a pleasant sight but do you know that a lot" +"of species of plants are completely destroyed to grow the type of grass on" +"the lawn? Moreover the grass usually grown has been brought from other" +"countries." +"224 X Class Natural Resource" +" Observe a lawn in your area (if you have one) and see how it is" +"maintained. Find out from the gardener the different types of plants" +"that he removes from time to time." +"" +"" +"" +"" +"A" +"Do you think a farmer does the same thing on his farm?" +"Activity-2" +"" +"" +"" +"" +"AN" +"Find out how many types of insects are present in and around your" +"house. Do you find the same type of insects in all seasons? Make a chart" +"of insect types(in case you don’t know their names or take the help of" +"your elders) and note their occurrence for at least a week in each season." +"" +"" +"" +"" +"NG" +"Repeat for other seasons.Study for a year and find out when you have highest" +"varieties of them. Study them for subsequent years to see any of them" +"have disappeared." +"Some governments have established parks and sanctuary to protect" +"wildlife and their habitats. They are also working to abolish hunting and" +"LA" +"fishing practices that may cause the extinction of some species." +"" +"Fossil Fuels" +"Fossil fuels were produced Natural gas 7%" +"from the remains of ancient plants" +"TE" +"" +"and animals. They include coal, Oil 24%" +"petroleum (oil), and natural gas." +"Nuclier 1%" +"What do fossil fuels provide us? Energy" +"Why do we need to conserve Waste 24%" +"them?" +"T" +"" +"" +"Apart from its use in vehicles, Other 2%" +"many of the products we use today" +"ER" +"" +"" +"" +"" +"Coal 42%" +"are made from petroleum. These" +"include plastics, synthetic rubber," +"fabrics like nylon, medicines," +"cosmetics, waxes, cleaning fig-8: Percentage consumption of" +"products, medical devices etc. some resources in India" +"SC" +"" +"" +"" +"" +"We need to conserve fossil fuels so we don’t run out of them. However," +"there are other good reasons the pollution caused by them when burnt, to" +"limit our fossil fuel use." +"Scientists are exploring alternatives to fossil fuels. They are trying to" +"produce renewable biofuels to power cars and trucks. They have" +"successfully produced electricity using the sun, wind, water etc." +"" +"Free distribution by T.S. Government 2019-20 225" +" Do you know?" +"Seeds from the Jatropha curcas plant" +"" +"" +"" +"" +"A" +"are used for the production of bio-fuel," +"a crucial part of India’s plan to attain" +"" +"" +"" +"" +"AN" +"energy sustainability.Andhra Pradesh has" +"entered into a formal agreement with" +"Reliance Industries for Jatropha planting." +"The company has selected 200 acresof" +"land at Kakinada to grow Jatropha for" +"high quality biodiesel. The process of" +"" +"" +"" +"" +"NG" +"Jatropa Jatropa seed" +"preparation of bio-fuels is called Bio-" +"esterification." +"Everyone can help conserve fossil fuels by using them carefully." +"Turn off lights and other electronics when you are not using them." +"Purchase energy-efficient appliances." +"LA" +"Walk, ride a bicycle and use public transportation whenever possible." +"It is better to prefer public transport system like bus or train instead" +"of travel in personnel vehicles. Discuss in your class how this helps to" +"the society." +"TE" +"" +"Collect information about solar, wind, tidal and water power and" +"prepare a scrap book." +"Ask your teacher about nuclear energy and its impacts on ecosystem." +"Minerals" +"Earth’s supply of raw mineral resources is in danger. Many mineral" +"T" +"" +"" +"" +"deposits that have been located and mapped have been depleted. As the" +"ores for minerals like aluminum and iron become harder to find and extract," +"ER" +"" +"" +"" +"" +"their prices go up. This makes tools and machinery more expensive to" +"purchase and operate." +"Many mining methods, such as mountaintop removal mining (MTR-" +"Mountain Top Removal), devastate the environment. They destroy soil," +"plants, and animal habitats. Many mining methods also pollute water and" +"SC" +"" +"" +"" +"" +"air, as toxic chemicals leak into the surrounding ecosystem." +"Think why disasters like Uttarakhand happend?" +"Activity-3" +"Now a days people are revolting against mining." +"Collect any such incident of our state or neighbouring states from" +"your school library or news papers and conduct a seminar on it’s impact." +"226 X Class Natural Resource" +" Less wasteful mining methods and the recycling of materials will help" +"conserve mineral resources. In Japan, for example, car manufacturers recycle" +"many raw materials used in making automobiles. In the United States, nearly" +"" +"" +"" +"" +"A" +"one-third of the iron produced comes from recycled automobiles." +"Conservation- A vital concern" +"" +"" +"" +"" +"AN" +"“The interest in conservation is not a sentimental one but the discovery" +"of a truth well known to our ancient sages. The Indian tradition teaches us" +"that all forms of life - human, animal and plant are so closelyinter-linked" +"that disturbance of one gives rise to imbalance in the other”. (By Srimati" +"Indira Gandhi, while launching the world conservation strategy in India on" +"" +"" +"" +"" +"NG" +"6th March 1980)." +"In the 1960s most countries lived within their ecological resources." +"But the latest figure shows that today three-quarters of the human" +"population live in countries which consume more than they can replenish." +"The issue of replenishment is large yet we have our individual roles." +"LA" +"Small steps could become great efforts at conservation. What does" +"the Kothapally experience tell us about step towards management and" +"conservation?" +"You may have already come across the four R’s to save the environment." +"TE" +"" +"They are Reduce, Reuse, Recycle, Recover." +"1. Reduce: We can save water by repairing leaky taps and avoiding" +"a shower or switching off unnecessary lights and fans." +"Think of other things that you could reduce usage of." +"Do you think it is necessary to have a lot of lighting for" +"decoration during celebrations?" +"T" +"" +"" +"2. Reuse: things that you often tend to throw away, like paper and" +"wrapping papers. This would save plants and minimise pollution." +"ER" +"" +"" +"" +"" +"What other things could you reuse to save our resources?" +"3. Recycle: It is the process of converting waste materials into fig-9: Bag from" +"new materials and objects (eg) some metals, glass, paper etc. waste material" +"Recycling may not always be a very good option as recycling plastic" +"is a tricky process and can cause havoc. The chief problem lies in" +"SC" +"" +"" +"" +"" +"plastics’ complexity. There are as many types of plastic as their" +"uses. Since each type can only be recycled with its own kind," +"plastics need to be carefully sorted before they can be processed." +"Why should one sort wastes carefully before discarding them" +"from home?" +"fig-10:" +"Often we keep a plastic bag in our dustbins to discard waste," +"Recycling logo" +"is it a good practise?" +"Free distribution by T.S. Government 2019-20 227" +" 4. Recover: when we cut trees to construct industries or roads for" +"transportation, it is important to grow trees in another areas." +"Discuss about various programmes to implement ‘recover’ to" +"" +"" +"" +"" +"A" +"prevent environmental threat." +"Collect information about technology used for transplantation of" +"" +"" +"" +"" +"AN" +"trees and discuss in your class room." +"Conservation Groups" +"Governments enact laws defining how land should be used and which" +"areas should be set aside as parks and wildlife preserves. Governments" +"" +"" +"" +"" +"NG" +"also enforce laws designed to protect the environment from pollution," +"such as requiring factories to install pollution-control devices. Finally," +"governments often provide incentives for conserving resources." +"Many international organizations are also dedicated to conservation." +"Members support causes such as saving rain forests, protecting threatened" +"animals, and cleaning up the air." +"LA" +"The International Union for the Conservation of Nature (IUCN) is an" +"alliance of governments and private groups founded in 1948. The IUCN" +"works to protect wildlife and habitats. In 1980, the group proposed a world" +"conservation strategy. Many governments have used the IUCN model to" +"develop their own conservation plans. In addition, the IUCN monitors the" +"TE" +"" +"status of endangered wildlife, threatened national parks and preserves, and" +"other environments around the world. Take Kothapally village as an example;" +"discuss the role of organizations involved in conservation and that of the" +"villagers." +"Can international, national or state organizations alone manage a" +"T" +"" +"" +"resource? Who are all involved in the whole process of management?" +"Suggest some ways in which you and your friends would like to" +"manage a resource?" +"ER" +"" +"" +"" +"" +"Are we also an important resource of nature? How?" +"Find out the usage of water in Litres per day in your home? Do you" +"actually require that much water and how much water is enough in" +"accordance with National standards?" +"SC" +"" +"" +"" +"" +"It is time to know our responsibilities to protect natural resources for" +"future generations." +"" +"" +"Key words" +"Percolation tank, Micro-irrigation, Borewells, Sustainable development, Biofuels" +"Contour strip farming, Dyke Management" +"" +"228 X Class Natural Resource" +" What we have learnt" +"" +"" +"" +"" +"A" +"Management of resources is essential for their conservation and restoration." +"Resources are usually local specific and local people need to have control over them." +"People need to be motivated to reduce pressure on the environment by reducing utilization of" +"" +"" +"" +"" +"AN" +"resources and reusing some of them." +"We must use our resources judiciously especially fossil fuels, coal and petroleum as they will be" +"ultimately exhausted." +"Interstate and intercountry disputes should not hamper availability of a resource." +"" +"" +"" +"" +"NG" +"Improve your learning" +"" +"1. The BP statistical Review of World Energy in June measured total global oil at 188.8 million tonnes," +"from proved oil resources at the end of 2010. This is only enough for oil to last for the next 46.2" +"years. What measures should be taken to conserve oil? What will happen if we do not conserve" +"it?(AS1)" +"LA" +"2. Here is a news strip, read it carefully and answer the following questions" +"Villagers oppose sand mining project Santhabommali (Srikakulam): People of more than 20 villages" +"in two mandals of Srikakulamhave raised a banner of revolt against the proposed beach sand" +"mining project by a private company and threatened to intensify their agitation if the government" +"TE" +"" +"does not cancel the project. The sand mining is being taken up to extract rich minerals from the" +"area. The villages are located around the forest belt were mining was initiated.(AS1)" +"i) Do you think the villagers are doing a right thing to agitate? Why?" +"ii) What resources are the villagers trying to save by their agitation?" +"ill the villagers be benefitted by the rich minerals extracted from sand?" +"iii) Will" +"T" +"" +"" +"iv) Why does the private company want to carry out mining in the beach area?" +"v) What is the role of the government in this aspect?" +"vi) How will mining in that piece of land affect people of the area?" +"ER" +"" +"" +"" +"" +"3. What is sustainable development?How is it useful in natural resource management?(AS1)" +"4. Write a detailed note on management of a natural resource.(AS1)" +"5. Suggest some ways of reusing a resource in your locality?(AS1)" +"6. Why should we conserve forests and wild life?(AS1)" +"7. Suggest some approaches towards the conservation of forests.(AS1)" +"SC" +"" +"" +"" +"" +"8. Natural resources are decreased more rapidly. Guess what will be the consequences?(AS2)" +"9. Prepare a questionnaire to conduct an interview at a petrol filling station personnel about consumption" +"of fossil fuels?(AS2)" +"10. Prepare model for rain water harvesting / energy saving / soil management, reflecting your innovative" +"thoughts. (AS3)" +"11. List out names of villages farmers and procedure followed for restoration of any natural resource in" +"your area.(AS4)" +"" +"Free distribution by T.S. Government 2019-20 229" +" 12. You might have heard the Natural Gas drillings near Kakinada by ONGC(Oil and Natural Gas" +"Corporation). Collect information and prepare a note on the status of Gas production at the" +"basin.(AS4)" +"" +"" +"" +"" +"A" +"13. Does your village or nearest city has a recycling unit of waste materials? Write in detail the steps" +"involved in it.(AS4)" +"14. Collect any graph that shows oil (petroleum) consumption in India.(AS4)" +"" +"" +"" +"" +"AN" +"i) Does the production meet consumption in India?" +"ii) During which period of time shows highest increase in consumption rate?" +"iii) What change have you observed in the production from past ten years, for example 2006-2016?" +"iv) Suggest some ways to bring down consumption of petroleum." +"15. Proper utilisation of natural resources is the way to show gratitude to our nation. Can you support" +"" +"" +"" +"" +"NG" +"this statement? Give your argument.(AS6)" +"16. Crop selection and cultivation should be based on availability of water. Prepare a slogan to bring" +"awareness among farmers about this?(AS7)" +"" +"Fill in the blanks" +"LA" +"1. ................... plants are used for production of biofuel." +"2. Bio diversity is important for more than just food and for ................ also." +"3. Example for nonrenewable resource is .........................." +"4. ........................ is the alternative method to prevent ground water depletion." +"TE" +"" +"5. Cultivation of paddy is suitable for ................ areas." +"" +"Choose the correct answer" +"" +"6. Percolation tanks helps to ( )" +"(A) supply water for agriculture (B) increase ground water level" +"T" +"" +"" +"" +"(C) preserve rain water (D) prevent overflow of water from tanks during rainy season" +"7. Which of the following practice is suitable to farmer with less water resources ( )" +"ER" +"" +"" +"" +"" +"(i) select short term crops, (ii) cultivate comercial crops, (iii) adapt drip system, (iv) crop holiday" +"(A) i, iii (B) i, ii, iii (C) i, iv (D) iii, iv" +"8. Which of the fossil fuel reserves decrease more rapidly in India ( )" +"(A) natural gas (B) coal (C) petroleum (D) all" +"9. Huge amount of toxic chemicals leak into the surrounding eco system because of ( )" +"SC" +"" +"" +"" +"" +"(A) industries (B) mining (C) pesticides (D) modern technology" +"10. Sustainable development means ( )" +"(A) prevention of wastage (B) stable growth" +"(C) development without damaging (D) high yieldings in less time" +"Courtesy- Case 1: V. Rantha Reddy, Centre for Economics and Social Studies, Hyderabad." +"Case 2: Paper on water management in Andhra Pradesh by Dr. M.D. Reddy, Water Technology" +"Centre ANGAR Agriculture Univeristy, Hyderabad." +"" +"230 X Class Natural Resource" +" "