The yellow-throated longclaw is a bird that lives on the dry savanna of Africa. It looks almost exactly like another bird, the western meadowlark of North America. Although the birds look very similar, they are not even in the same taxonomic family. Scientists think the birds look alike because the two species developed under similar environmental pressures, even though they developed thousands of miles apart. Which process does their development demonstrate? [SEP] A. sexual selection [SEP] B. disruptive selection [SEP] C. divergent evolution [SEP] D. convergent evolution

Answer: D


The reaction that releases energy for use by the cell occurs in which site? [SEP] A. Golgi apparatus [SEP] B. endoplasmic reticulum [SEP] C. cytoplasmic membrane [SEP] D. mitochondrial membrane

Answer: D


Why do doctors suggest that people get a flu vaccine each year? [SEP] A. Viruses replicate more rapidly over time. [SEP] B. Viruses can mutate from year to year. [SEP] C. Vaccines are absorbed by the body after a year. [SEP] D. Vaccines get stronger over time.

Answer: B


Which of the following events involves a consumer and producer in a food chain? [SEP] A. A cat eats a mouse. [SEP] B. A deer eats a leaf. [SEP] C. A hawk eats a mouse. [SEP] D. A snake eats a rat.

Answer: B


The change from day to night on Earth can be explained by [SEP] A. the movement of the Sun. [SEP] B. the rotation of Earth. [SEP] C. the movement of the Moon. [SEP] D. the tilt of Earth.

Answer: B


Which part of a bicycle BEST moves in a circle? [SEP] A. Seat [SEP] B. Frame [SEP] C. Foot pedal [SEP] D. Kickstand

Answer: C


When animals use energy, what is always produced? [SEP] A. sugar [SEP] B. heat [SEP] C. oxygen [SEP] D. starch

Answer: B


Which type of rock is formed when hot lava cools? [SEP] A. coal [SEP] B. igneous [SEP] C. limestone [SEP] D. metamorphic

Answer: B


Which environmental factor would most likely prevent an orange tree from surviving in the desert? [SEP] A. the lack of moisture [SEP] B. the high levels of heat [SEP] C. the extra amount of wind [SEP] D. the low levels of sunlight

Answer: A


After a rainstorm, a big pile of rocks blocks part of a mountain road. Which event most likely caused the rocks to move onto the road? [SEP] A. a tsunami [SEP] B. a blizzard [SEP] C. a landslide [SEP] D. a hurricane

Answer: C


What would be the result of adding one proton to an atom? [SEP] A. one electron would be added [SEP] B. the atomic number would change [SEP] C. the total mass of the atom would decrease [SEP] D. the electrical charge would become neutral

Answer: B


What would be the best source to find information about DNA testing? [SEP] A. local newspaper [SEP] B. TV news report [SEP] C. scientific journals [SEP] D. world almanac

Answer: C


In what section of Earth do earthquakes happen? [SEP] A. crust [SEP] B. mantle [SEP] C. inner core [SEP] D. outer core

Answer: A


A complete fossil has been found of a type of bird that cannot be identified. What can most likely be determined about the bird from the fossil? [SEP] A. The bird lived for a very short time. [SEP] B. The bird lived in a dry environment. [SEP] C. The bird existed at one time but is now extinct. [SEP] D. The bird was not well preserved during the process of fossilization.

Answer: C


When large areas of the rainforests are cleared and burned, climate can be affected. Which best explains how rainforest destruction can contribute to the greenhouse effect? [SEP] A. by threatening native plants and animals [SEP] B. by increasing the rate of soil erosion [SEP] C. by increasing the water levels in oceans [SEP] D. by releasing carbon into the atmosphere

Answer: D


Which information is used in a station model? [SEP] A. yearly average precipitation [SEP] B. daily average barometric pressure [SEP] C. number of lightning strikes [SEP] D. wind direction in a particular point and time

Answer: D


Which part of a plant is most responsible for using energy from the Sun to produce food for the plant? [SEP] A. flower [SEP] B. leaf [SEP] C. root [SEP] D. stem

Answer: B


Which natural formation is the best example of the result of both constructive and destructive forces such as weathering, erosion, and deposition of sediment? [SEP] A. The Mid-Atlantic Ridge [SEP] B. The Grand Canyon [SEP] C. The Mojave Desert [SEP] D. The Himalayan Mountains

Answer: B


Which characteristic helps a fox find food? [SEP] A. sense of smell [SEP] B. thick fur [SEP] C. long tail [SEP] D. pointed teeth

Answer: A


Tay-Sachs disease is a recessive genetic disorder. If only one gene is present, an individual is a carrier. What is the probability of two healthy Tay-Sachs carriers having a child that has the disease? [SEP] A. 0% [SEP] B. 25% [SEP] C. 50% [SEP] D. 75%

Answer: B


Two identical lamps contain the same amount of different types of oil. They are allowed to burn until all the oil has been burned. Which measurement will best provide the total difference in chemical energy between the two oils? [SEP] A. final weight of lamp [SEP] B. original volume of oil [SEP] C. time it took for lamps to use oil [SEP] D. height of flame produced by lamp

Answer: C


Which disease is a result of abnormal cell division? [SEP] 1. AIDS [SEP] 2. cancer [SEP] 3. chicken pox [SEP] 4. common cold

Answer: 2


During which season of the year would a rabbit's fur be thickest? [SEP] A. fall [SEP] B. spring [SEP] C. summer [SEP] D. winter

Answer: D


Which property of an element is determined by adding the number of protons and number of neutrons? [SEP] A. atomic mass [SEP] B. atomic radius [SEP] C. electrical charge [SEP] D. electrical potential

Answer: A


Which of these cycles takes 24 hours? [SEP] A. Earth rotating on its axis [SEP] B. Earth revolving around the Sun [SEP] C. the Moon rotating on its axis [SEP] D. the Moon revolving around Earth

Answer: A


Lemon juice turns litmus paper red, is corrosive and tastes sour. Lemon juice is classified as [SEP] A. an acid. [SEP] B. a base. [SEP] C. an element. [SEP] D. More information is needed to classify lemon juice.

Answer: A


A child walks across a carpet and generates an electrical charge. The child will get a slight shock by touching a [SEP] A. metal doorknob. [SEP] B. plastic toy. [SEP] C. rubber ball. [SEP] D. wooden block.

Answer: A


Which animal eats only plants? [SEP] A. Cat [SEP] B. Dog [SEP] C. Lion [SEP] D. Rabbit

Answer: D


A newborn kangaroo has the ability to crawl into its mother's pouch to drink milk. This is an example of [SEP] A. migration. [SEP] B. an instinct. [SEP] C. hibernation. [SEP] D. a learned behavior.

Answer: B


Which characteristic is shared by Earth and the Moon? [SEP] A. glaciers [SEP] B. flowing water [SEP] C. an atmosphere that contains oxygen [SEP] D. an orbit created by the force of gravity

Answer: D


The Piedmont and Coastal Plains regions in Maryland produce crops such as corn, soybeans, wheat, tobacco, tomatoes, and apples. Which environmental factor most likely influences which crops are grown in these regions? [SEP] A. soil quality [SEP] B. wind speeds [SEP] C. bird migration [SEP] D. water temperature

Answer: A


Which organ system is responsible for the exchange of oxygen and carbon dioxide between the body and the environment? [SEP] A. circulatory [SEP] B. excretory [SEP] C. immune [SEP] D. respiratory

Answer: D


Which of these will always produce a magnetic field? [SEP] A. a bar of steel [SEP] B. a bar of aluminum [SEP] C. an electric current [SEP] D. an electric charge

Answer: C


The periodic table provides information about the atoms of different elements. Which is a characteristic of an atom determines what element it is? [SEP] A. number of neutrons [SEP] B. number of protons [SEP] C. state of matter [SEP] D. atomic mass

Answer: B


Joel made some measurements and recorded this data: Sample 1 - 45 mL Sample 2 - 15 mL Sample 3 - 30 mL Sample 4 - 20 mL Which of these tools would most likely have been used to obtain these measurements? [SEP] A. test tube [SEP] B. meter stick [SEP] C. spring scale [SEP] D. graduated cylinder

Answer: D


A teacher demonstrates a chemical reaction. A student observes that the test tube in which the reaction occurs becomes warm. What is the source of the thermal energy generated by the reaction? [SEP] A. energy stored in the reactants [SEP] B. breaking bonds of the reactants [SEP] C. kinetic energy absorbed by the reaction [SEP] D. potential energy absorbed by the reaction

Answer: A


Deer provide food for wolves. How does this relationship also benefit the deer herd? [SEP] A. by protecting deer from other predators [SEP] B. by controlling the deer population [SEP] C. by decreasing diversity within the herd [SEP] D. by protecting the deer from disease

Answer: B


In what way does society benefit from research on diseases? [SEP] A. New illnesses will develop. [SEP] B. Doctors will visit their patients at home. [SEP] C. More families will move closer to hospitals. [SEP] D. Many illnesses will be prevented or cured.

Answer: D


Which energy transformation takes place in a gasoline lawn mower? [SEP] A. potential energy to electrical energy [SEP] B. electrical energy to potential energy [SEP] C. kinetic energy to chemical energy [SEP] D. chemical energy to mechanical energy

Answer: D


Which of the following can only be seen with a telescope? [SEP] A. the moon-like phases of Venus [SEP] B. the phases of Earth's moon [SEP] C. a lunar eclipse [SEP] D. a solar eclipse

Answer: A


The rocks that form most of the Sierra Nevada are granitic rocks. This means that the mountains were most likely formed by [SEP] A. strike-slip faults. [SEP] B. transform boundaries. [SEP] C. volcanic activity. [SEP] D. land subsidence.

Answer: C


In 1872, the United States created a national park called Yellowstone. The park includes more than two million acres in the three states of Idaho, Montana, and Wyoming. Which statement best explains why national parks have a positive effect on ecosystems? [SEP] A. National parks limit people from seeing wildlife. [SEP] B. National parks limit mining, logging, and hunting. [SEP] C. National parks protect land for farmers and ranchers. [SEP] D. National parks protect land for people to build houses.

Answer: B


According to the endosymbiotic theory, double-membrane mitochondria originated as a result of some larger eukaryotic cells with flexible membranes engulfing smaller prokaryotic cells. Which of these explains where the outer layer of the double membrane of the mitochondria originated? [SEP] A. the plasma membrane of the eukaryotic host [SEP] B. the nuclear membrane of the eukaryotic host [SEP] C. the ribosomes of the engulfed prokaryotic cell [SEP] D. the lysosomes of the engulfed prokaryotic cell

Answer: A


Toni got a cut on her arm while playing in a softball game. A few weeks later, the cut was healed. Which process is most responsible for repairing the cut? [SEP] A. signals transported by nerve cells [SEP] B. exchange of oxygen in the lungs [SEP] C. transport of waste by blood [SEP] D. reproduction of skin cells

Answer: D


A pot of cold water was heated on a stove until the water boiled. Which of the following best explains why the water was able to boil? [SEP] A. The hot stove absorbed cold from the pot. [SEP] B. The cold water absorbed heat from the pot. [SEP] C. The hot stove gave off heat to the surrounding air. [SEP] D. The cold water gave off cold to the surrounding air.

Answer: B


A spring-fed stream forms a pond that contains watercress plants, minnows, and crayfish. The pond receives 5 hours of direct sunlight every day. Which of the following is an abiotic factor in this ecosystem? [SEP] A. the pond water [SEP] B. the watercress plants [SEP] C. the minnows [SEP] D. the crayfish

Answer: A


A modern theory of the origin of the universe proposes that the first atoms formed were primarily atoms of which element? [SEP] A. iron [SEP] B. carbon [SEP] C. helium [SEP] D. hydrogen

Answer: D


A star is a large astronomical body that [SEP] A. reflects light. [SEP] B. condenses light. [SEP] C. emits light. [SEP] D. absorbs light.

Answer: C


What happens to water when it boils? [SEP] A. It changes color. [SEP] B. It becomes heavier. [SEP] C. It changes into water vapor. [SEP] D. It stops bubbling.

Answer: C


Ms. Bristol measured the mass of a closed beaker containing several ice cubes. The mass was 100 g. An hour later, after the ice cubes had melted, Ms. Bristol measured the mass of the beaker again. What was the mass of the beaker of water the second time? [SEP] A. 50 g [SEP] B. 75 g [SEP] C. 100 g [SEP] D. 125 g

Answer: C


A student has two solid samples of the same substance. Which property do the substances most likely have in common? [SEP] A. density [SEP] B. mass [SEP] C. shape [SEP] D. volume

Answer: A


In which object does chemical energy most likely transform into electrical energy? [SEP] A. a candle [SEP] B. a mirror [SEP] C. a flashlight [SEP] D. a television

Answer: C


What is the mass number of an atom with 17 protons, 17 electrons, and 18 neutrons? [SEP] A. 17 [SEP] B. 34 [SEP] C. 35 [SEP] D. 52

Answer: C


Some machines can remove the salt that is in seawater. How does removing salt from seawater most help people? [SEP] A. provides useable drinking water [SEP] B. creates cleaner water for rivers [SEP] C. enables more fish to live in lake water [SEP] D. allows more plants to grow along rivers

Answer: A


Which body system is most affected by a disease that causes the bones to become weak and brittle? [SEP] A. excretory [SEP] B. muscular [SEP] C. skeletal [SEP] D. nervous

Answer: C


Why can a small fire be put out by placing a heavy blanket over it? [SEP] A. This lowers the temperature. [SEP] B. This makes the flames smaller. [SEP] C. This absorbs the burning substance. [SEP] D. This keeps oxygen from reaching the fire.

Answer: D


There is a river at the base of Mount Tom. In the spring the water level is usually very high. In the summer it is lower. The higher level of water during the spring comes from [SEP] A. hurricanes. [SEP] B. melting snow. [SEP] C. tornadoes. [SEP] D. evaporating water.

Answer: B


Earthquake waves are recorded by seismograph machines. What does an earthquake wave transmit? [SEP] A. energy [SEP] B. light [SEP] C. particles [SEP] D. speed

Answer: A


The snowshoe hare was once common in Maryland. In 1986, researchers in the state noted that the snowshoe hare was no longer found in Maryland. Which statement best explains why the snowshoe hare is no longer found in Maryland? [SEP] A. Water quality has improved. [SEP] B. There are too many trees. [SEP] C. The temperature is too cold. [SEP] D. Housing developments have replaced fields.

Answer: D


In the initial stages of manned space exploration, scientists needed to address adequate nutrition to provide astronauts with energy throughout the mission. Which of these criteria could not be used when considering food and energy for astronauts during manned space flights? [SEP] A. history of space food [SEP] B. food crumbs in zero gravity [SEP] C. rehydration of certain foods [SEP] D. food storage for long periods

Answer: A


Which is the best example of evaporation? [SEP] A. raindrops freezing [SEP] B. an ice cube melting [SEP] C. a puddle drying in the sun [SEP] D. a sponge soaking up water

Answer: C


In a forest community, trees produce leaves that can be eaten by deer. The leaves also fall to the forest floor during autumn. Fungi break the leaves down into nutrients that enter the soil. What is the decomposer in this forest community? [SEP] A. the soil [SEP] B. the deer [SEP] C. the trees [SEP] D. the fungi

Answer: D


Compared to Earth, the Moon is [SEP] A. drier. [SEP] B. larger. [SEP] C. heavier. [SEP] D. brighter.

Answer: A


What process forms an image in a mirror? [SEP] A. absorbing light [SEP] B. reflecting light [SEP] C. refracting light [SEP] D. transmitting light

Answer: B


Which is an example of a physical change? [SEP] A. ice melting [SEP] B. nail rusting [SEP] C. bread baking [SEP] D. wood burning

Answer: A


Which of the following describes an object that must have a net negative charge? [SEP] A. It contains more molecules than atoms. [SEP] B. It contains more electrons than protons. [SEP] C. It is carrying an electric current. [SEP] D. It is made of metal.

Answer: B


Rocks found on Earth are classified as sedimentary, metamorphic, or igneous based on [SEP] A. where the rocks were found. [SEP] B. how the rocks were formed. [SEP] C. the composition of the rocks. [SEP] D. the color and shape of the rocks.

Answer: B


Which of the following is formed when two elements combine chemically? [SEP] A. an atom [SEP] B. a compound [SEP] C. an electron [SEP] D. a mixture

Answer: B


Which of the following is the most important safety practice when using a rock hammer on a geology field trip? [SEP] A. wear gloves while breaking rocks [SEP] B. wear goggles while breaking rocks [SEP] C. have a bucket of sand in case of sparks [SEP] D. have a clean eye-wash station available

Answer: B


To which organ system do the esophagus, liver, pancreas, small intestine, and colon belong? [SEP] A. reproductive system [SEP] B. excretory system [SEP] C. digestive system [SEP] D. endocrine system

Answer: C


When sodium hydroxide reacts with a copper nitrate solution, the reaction vessel needs to be kept on ice to slow down the reaction. What best describes this reaction? [SEP] A. an exothermic reaction that absorbs energy [SEP] B. an exothermic reaction that releases energy [SEP] C. an endothermic reaction that absorbs energy [SEP] D. an endothermic reaction that releases energy

Answer: B


Scientists measured the patterns of spectral lines given off by distant galaxies and concluded that almost all of these galaxies are moving away from Earth. What did the scientists observe directly? [SEP] A. a shift toward longer wavelengths of light [SEP] B. a shift toward shorter wavelengths of light [SEP] C. the absence of wavelengths in the visible light range [SEP] D. the compression of wavelengths in the visible light range

Answer: A


When a multicellular organism is damaged, it will repair itself as [SEP] A. it mutates. [SEP] B. the cells work together. [SEP] C. the cells move. [SEP] D. it makes its own food.

Answer: B


Genes are located on chromosomes which are composed of [SEP] A. DNA. [SEP] B. RNA. [SEP] C. ATP. [SEP] D. ADP.

Answer: A


Which of the following best describes the number of chromosomes in a normal human liver cell? [SEP] A. 23 pairs of chromosomes [SEP] B. 46 different types of chromosomes [SEP] C. 46 male chromosomes and 46 female chromosomes [SEP] D. 23 original chromosomes and 23 duplicate chromosomes

Answer: A


A student measures the growth of a group of plants given different amounts of fertilizer. Which data display should the student use to compare the growth of the plants? [SEP] A. bar graph [SEP] B. scatterplot [SEP] C. line graph [SEP] D. pie chart

Answer: C


What is a large buildup of moving ice and snow called? [SEP] A. drumlin [SEP] B. delta [SEP] C. glacier [SEP] D. moraine

Answer: C


Which of these conditions would most likely be shown in the fossil record as a reason for mass extinctions? [SEP] A. increased competition for resources [SEP] B. falling sea levels and global cooling [SEP] C. organisms with beneficial traits [SEP] D. increased solar activity

Answer: B


One of the functions of a topographic map is to [SEP] A. gauge local rainfall amounts. [SEP] B. study the area's geological history. [SEP] C. predict the severity of earthquakes. [SEP] D. show the surface features of an area.

Answer: D


Reptiles become more active as the day gets warmer. This is because [SEP] A. they have scaly skin. [SEP] B. they have slimy skin. [SEP] C. their body temperature stays at a constant level. [SEP] D. their body temperature changes with the environment.

Answer: D


Which scientific model could be used to predict the properties of an element? [SEP] 1. closed loop system [SEP] 2. Punnett square [SEP] 3. Periodic Table [SEP] 4. water cycle chart

Answer: 3


Some of the thermal structure of Earth is the result of a combination of chemical composition, temperature, and pressure. Which is a boundary that best demonstrates a contact point between layers having relatively the same temperature and chemical composition? [SEP] A. lithosphere and mesosphere [SEP] B. inner core and outer core [SEP] C. outer core and mantle [SEP] D. mantle and crust

Answer: B


A hillside along a highway has exposed layers of undisturbed sedimentary rock. Which method would be best for scientists to use to determine the relative age of these sedimentary rock layers? [SEP] A. apply the law of superposition [SEP] B. calculate the rate of radiometric decay [SEP] C. apply the law of crosscutting relationships [SEP] D. calculate the rate of tectonic plate movement

Answer: A


What are petri dishes used for in a lab? [SEP] A. reflecting light to form images [SEP] B. measuring the mass of molecules [SEP] C. growing bacteria in a controlled setting [SEP] D. observing the strength of physical forces

Answer: C


How do most fish get the oxygen they need to survive? [SEP] A. They take in water and break it down into hydrogen and oxygen. [SEP] B. Using their gills, they take in oxygen that is dissolved in water. [SEP] C. They get their oxygen from the food they eat. [SEP] D. They come to the surface every few minutes to breathe air into their lungs.

Answer: B


Miranda's neighbors have an apple tree in their yard. What is the source of energy for the apple tree? [SEP] A. rain [SEP] B. soil [SEP] C. sunlight [SEP] D. wind

Answer: C


Some types of trees are able to survive the heat of a forest fire. Which of the following characteristics would best help a tree survive a fire? [SEP] A. large leaves [SEP] B. shallow roots [SEP] C. thick bark [SEP] D. thin trunks

Answer: C


Which of the following would most likely happen if grasses and shrubs were removed from a rural Massachusetts ecosystem? [SEP] A. There would be an increase in consumers in the ecosystem. [SEP] B. There would be an increase of photosynthesis in the ecosystem. [SEP] C. There would be a decrease in food energy produced by the ecosystem. [SEP] D. There would be a decrease of carbon dioxide available to the ecosystem.

Answer: C


In 2004, Maryland recycled more than 35% of all of the waste the state produced. Which of these benefits does recycling provide to Maryland? [SEP] A. fewer wild animals [SEP] B. decreased farm crops [SEP] C. less trash sent to landfills [SEP] D. decreased use of electricity

Answer: C


A student finds a round, smooth pebble on a beach. Which action made the pebble smooth? [SEP] A. rain falling [SEP] B. wind blowing [SEP] C. snow melting [SEP] D. waves moving

Answer: D


The position of the liver in the circulatory system maximizes its ability to filter out harmful chemicals as soon as they enter the bloodstream. Blood travels to the liver from the [SEP] A. nervous system. [SEP] B. digestive system. [SEP] C. immune system. [SEP] D. excretory system.

Answer: B


A student recorded the amount of rain that fell in one year in his city. What is the best way for him to organize his information? [SEP] A. diagram [SEP] B. graph [SEP] C. journal [SEP] D. map

Answer: B


While Anna was testing a circuit, she dropped a light bulb. What is the safest thing Anna can do? [SEP] A. get a new bulb to finish the test [SEP] B. push the broken glass under a table [SEP] C. tell her teacher that she broke the bulb [SEP] D. ask her partner to help pick up the broken glass

Answer: C


Sugar is added to water and the mixture is stirred. Which observation is evidence that the sugar dissolved in the water? [SEP] A. Less sugar is visible. [SEP] B. The water is cloudy. [SEP] C. The sugar turned into crystals. [SEP] D. Bubbles formed in the water.

Answer: A


The direction water flows in a river depends on [SEP] A. the length of the river [SEP] B. the slope of the land [SEP] C. the type of rock over which the water flows [SEP] D. the location of the North Pole

Answer: B


A soccer player kicks a soccer ball across a field. Which factor has the most effect on the distance the soccer ball travels? [SEP] A. the color of the ball [SEP] B. the force of the kick [SEP] C. the length of the field [SEP] D. the temperature of the air

Answer: B


Many cells have a nucleus that contains chromosomes. These chromosomes carry genes that are composed of [SEP] 1. hormones [SEP] 2. DNA molecules [SEP] 3. minerals and water [SEP] 4. undigested food molecules

Answer: 2


Which items would best protect a group of students while investigating a forest ecosystem? [SEP] A. short pants and T-shirts [SEP] B. short pants and long-sleeved shirts [SEP] C. long pants and T-shirts [SEP] D. long pants and long-sleeved shirts

Answer: D


A student needs to find the mass of an atom. The numbers of which atomic particles determines the mass of the atom? [SEP] A. only its protons [SEP] B. only its electrons [SEP] C. both its protons and neutrons [SEP] D. both its neutrons and electrons

Answer: C


Which activity is necessary for humans to maintain good health? [SEP] A. reading [SEP] B. resting [SEP] C. driving [SEP] D. talking

Answer: B


A student completes several tasks while making breakfast. During which task does the student make a solution? [SEP] A. adding sugar to tea [SEP] B. pouring milk on cereal [SEP] C. spreading jelly on toast [SEP] D. sprinkling cheese on eggs

Answer: A


Which natural event can dry out plants and cause wildfires? [SEP] A. drought [SEP] B. earthquake [SEP] C. flood [SEP] D. tornado

Answer: A


Where would nitrogen most easily be found in the nitrogen cycle? [SEP] A. in animal waste [SEP] B. in drinking water supplies [SEP] C. in underground mineral deposits [SEP] D. in carbon dioxide released by factories into the atmosphere

Answer: A


Before it rains water must collect in [SEP] A. clouds. [SEP] B. snow. [SEP] C. sleet. [SEP] D. fog.

Answer: A


Which atmospheric phenomena are created by the interaction of charged particles with Earth's magnetosphere? [SEP] A. auroras [SEP] B. tornadoes [SEP] C. rainbows [SEP] D. inversions

Answer: A


Which of these BEST describes the way a feather feels? [SEP] A. Colorful [SEP] B. Soft [SEP] C. Low [SEP] D. Bright

Answer: B


A tight metal lid on a jar of pickles may loosen when it has been held in hot water. This is because the hot water causes the [SEP] A. glass jar to contract [SEP] B. metal lid to contract [SEP] C. glass jar to expand more than the metal lid expands [SEP] D. metal lid to expand more than the glass jar expands

Answer: D


A scientist reads about an experiment conducted by a researcher.The scientist conducts the same experiment and collects data but this data contradicts what was published by the researcher. What should the scientist do since the data from the two experiments is contradictory? [SEP] A. Repeat the experiment to check the data collected. [SEP] B. Contact the researcher who first performed the experiment. [SEP] C. Contact the scientific journal that published the experiment. [SEP] D. Disregard the data collected since the experiment was published.

Answer: A


The organisms that convert solar energy and raw materials into food are [SEP] A. producers. [SEP] B. consumers. [SEP] C. herbivores. [SEP] D. decomposers.

Answer: A


Large amounts of metals like iron and aluminum are found in [SEP] A. dead trees [SEP] B. water [SEP] C. animal bones [SEP] D. oil wells [SEP] E. rocks

Answer: E


Which of these occurs if myosin fails to bind to actin during muscle contraction? [SEP] A. The muscle cells will lose ATP. [SEP] B. The muscle cells will remain relaxed. [SEP] C. The muscle cells will produce lactic acid. [SEP] D. The muscle cells will lose calcium ions.

Answer: B


How are cells able to produce the proteins required by certain conditions? [SEP] A. by synthesizing new genes [SEP] B. by altering existing genes [SEP] C. by expressing existing genes [SEP] D. by mutating new genes

Answer: C


An organism's cells include organelles and a cell wall. In which taxonomic group or groups might the organism be classified? [SEP] A. plants only [SEP] B. bacteria or archaea [SEP] C. plants, fungi, or protists [SEP] D. bacteria, fungi, or protists

Answer: C


Which of these structures produces male gametes in humans? [SEP] A. testes [SEP] B. ovaries [SEP] C. scrotum [SEP] D. fallopian tube

Answer: A


The length of a year is equivalent to the time it takes for one [SEP] 1. rotation of Earth [SEP] 2. rotation of the Sun [SEP] 3. revolution of Earth around the Sun [SEP] 4. revolution of the Sun around Earth

Answer: 3


Which of these organisms has cells with cell walls? [SEP] A. bluebird [SEP] B. A pine tree [SEP] C. A ladybug [SEP] D. A fox squirrel

Answer: B


Which is the result of mitosis? [SEP] A. two identical nuclei [SEP] B. four unique cells [SEP] C. a decrease in genes [SEP] D. a new protein

Answer: A


Which of these materials on the walls of a room would work best to keep sound from making an echo? [SEP] A. marble [SEP] B. carpet [SEP] C. wood [SEP] D. glass

Answer: B


The starch and water molecules in potato cells are stored in what organelle? [SEP] A. mitochondrion [SEP] B. nucleus [SEP] C. ribosome [SEP] D. vacuole

Answer: D


Which animals live part of their lives in water and part on land, and go through metamorphosis? [SEP] A. reptiles [SEP] B. amphibians [SEP] C. birds [SEP] D. mammals

Answer: B


A student puts two identical plants in the same type and amount of soil. She gives them the same amount of water. She puts one of these plants near a sunny window and the other in a dark room. This experiment tests how the plants respond to [SEP] A. light [SEP] B. air [SEP] C. water [SEP] D. soil

Answer: A


Humans need food to grow and survive. Food that is not used immediately by the body for energy is [SEP] A. stored for future use [SEP] B. converted to water for energy [SEP] C. used to remove wastes from cells [SEP] D. transformed into oxygen for survival

Answer: A


What structure surrounds the cell and regulates materials that enter and leave the cell? [SEP] A. nucleus [SEP] B. chloroplast [SEP] C. mitochondrion [SEP] D. cell membrane

Answer: D


In order for boulders to become sediments, the boulders must first be [SEP] A. heated and melted. [SEP] B. weathered and eroded. [SEP] C. recrystallized. [SEP] D. buried.

Answer: B


During which stage of an insect's life cycle does the female lay eggs? [SEP] A. nymph [SEP] B. larva [SEP] C. pupa [SEP] D. adult

Answer: D


When a dog smells food and begins drooling, it is responding to an external stimulus. Which of these describes a response to an internal stimulus? [SEP] A. A cat sees a mouse and crouches. [SEP] B. A parrot hears a name and repeats it. [SEP] C. A person eats spoiled food and vomits. [SEP] D. A worm senses water and moves to the surface.

Answer: C


Which is an example of melting? [SEP] A. Flowing water making a rock smooth [SEP] B. A carrot becoming soft when cooked [SEP] C. Sugar mixed into tea making the tea sweet [SEP] D. Butter changing into liquid in a warm pan

Answer: D


Students perform an investigation designed to measure the daily growth of a bean plant. Which should the students do every day of this investigation? [SEP] A. record data [SEP] B. form hypothesis [SEP] C. form conclusion [SEP] D. define variables

Answer: A


Ice cream in a bowl changed from solid to liquid in a few minutes. Which of the following most likely caused this change? [SEP] A. Bacteria grew in the ice cream. [SEP] B. Heat was added to the ice cream. [SEP] C. Water evaporated from the ice cream. [SEP] D. Frozen berries were sprinkled on the ice cream.

Answer: B


The change in the use of one model of the solar system to the use of another model resulted in major changes in science and society. Which two scientists produced the earlier and later models, respectively? [SEP] A. Hooke and Mendel [SEP] B. Newton and Galileo [SEP] C. Aristotle and Einstein [SEP] D. Ptolemy and Copernicus

Answer: D


An atom with a +1 charge has [SEP] A. lost a proton. [SEP] B. lost an electron. [SEP] C. gained a proton. [SEP] D. gained an electron.

Answer: B


Which is an example of a single-celled organism? [SEP] A. amoeba [SEP] B. insect [SEP] C. fish [SEP] D. worm

Answer: A


The Great Ocean Conveyer ocean current system runs north through the Atlantic from the equatorial region. If this current got disrupted, North American and European climates would become [SEP] A. rainier. [SEP] B. colder. [SEP] C. windier. [SEP] D. more humid.

Answer: B


Which region of the Milky Way contains a population that consists mostly of old stars? [SEP] A. the halo [SEP] B. the spiral arms [SEP] C. the nuclear bulge [SEP] D. the open clusters

Answer: A


When a switch to a ceiling fan is turned on, electrical energy is being transformed into [SEP] A. atomic energy. [SEP] B. potential energy. [SEP] C. chemical energy. [SEP] D. mechanical energy.

Answer: D


An agricultural scientist, George Washington Carver, is most famous for his research on [SEP] A. tobacco. [SEP] B. peanuts. [SEP] C. mold. [SEP] D. corn.

Answer: B


A student pours a clear liquid from a test tube into a beaker with a clear liquid already in it and notices that the mixture turns pink. The student infers the two clear liquids are different. This inference is a result of [SEP] A. class discussion. [SEP] B. previous knowledge. [SEP] C. temperature changes. [SEP] D. student observations.

Answer: D


In what leaf structure is photosynthetic tissue found? [SEP] A. cuticle [SEP] B. upper epidermis [SEP] C. mesophyll [SEP] D. vascular bundle

Answer: C


The crude oil extracted today was formed millions of years ago from the fossilized remains of algae and other tiny marine organisms. Most parts of the organisms decomposed soon after they died. Which biomolecules decomposed more slowly and became the basis of crude oil? [SEP] A. proteins [SEP] B. carbohydrates [SEP] C. fatty acids [SEP] D. nucleic acids

Answer: C


Temperatures below freezing are expected overnight. What might be done to protect plants growing outside? [SEP] A. trim the leaves [SEP] B. weed them [SEP] C. cover them [SEP] D. give them plant food

Answer: C


Prolonged exercise stimulates muscle cells to absorb sugar from the blood. This mechanism reduces stress placed on the body by signaling the body to produce [SEP] A. insulin. [SEP] B. lipids. [SEP] C. hemoglobin. [SEP] D. hydrochloric acid.

Answer: A


Which geologic feature is evidence that the North American plate once collided with the Eurasian and African plates? [SEP] A. the Appalachian Mountains [SEP] B. the Mohave Desert [SEP] C. the Mississippi River [SEP] D. the Great Lakes

Answer: A


During an experiment, a student reports that a liquid turned green when mixed with another liquid. This is an example of [SEP] A. a measurement [SEP] B. a prediction [SEP] C. an explanation [SEP] D. an observation

Answer: D


Which of the following causes a chemical change? [SEP] A. sugar added to soda [SEP] B. detergent added to water [SEP] C. lemon juice added to milk [SEP] D. salt added to water

Answer: C


Which human organ system exchanges gases with the environment? [SEP] A. endocrine [SEP] B. circulatory [SEP] C. respiratory [SEP] D. integumentary

Answer: C


Improvements in geological observation technologies have made it easier for scientists to locate resources in Earth's crust. These technologies have allowed for an increase in availability of which resource? [SEP] A. wind power [SEP] B. solar energy [SEP] C. fossil fuel [SEP] D. tidal energy

Answer: C


An engineer constructs a prototype from wood. Which of the following is the best tool for the engineer to use to make the prototype's surface smooth? [SEP] A. band saw [SEP] B. chisel [SEP] C. drill [SEP] D. sandpaper

Answer: D


If left in the sunshine, water in an open jar will [SEP] A. evaporate. [SEP] B. condense. [SEP] C. freeze. [SEP] D. melt.

Answer: A


In some locations, squirrels sleep for long periods of time during the winter months. Which of the following most likely causes these squirrels to sleep for long periods of time? [SEP] A. increase in humidity [SEP] B. decrease in temperature [SEP] C. clouds forming in the sky [SEP] D. winds blowing in the night

Answer: B


Which of the following helps the body to cool down? [SEP] A. shivering [SEP] B. sweating [SEP] C. running a fever [SEP] D. taking deep breaths

Answer: B


The brown fur of the arctic hare turns white in winter. How does this color change most likely help the arctic hare? [SEP] A. It helps the animal save water. [SEP] B. It helps the animal hide from predators. [SEP] C. It helps keep the animal cool. [SEP] D. It helps protect the animal from disease.

Answer: B


A group of students found metamorphic rocks near a campsite. The presence of metamorphic rocks is most likely evidence of [SEP] A. dinosaur activity [SEP] B. sediment deposition [SEP] C. high pressure [SEP] D. wind-borne sand

Answer: C


As water vapor condenses into liquid, which of the following can be formed? [SEP] A. ice [SEP] B. steam [SEP] C. frost [SEP] D. clouds

Answer: D


Which of these particles, when found in soil, contributes most to the water retention in soil? [SEP] A. gravel [SEP] B. sand [SEP] C. silt [SEP] D. clay

Answer: D


Which of the following forms of energy is released or absorbed in most chemical reactions? [SEP] A. light energy [SEP] B. electrical energy [SEP] C. sound energy [SEP] D. heat energy

Answer: D


Which of these must occur for sediments to form new rock? [SEP] A. precipitation [SEP] B. evaporation [SEP] C. partial melting [SEP] D. recrystallization

Answer: D


A student wants to find the most accurate account of a scientific discovery that took place within the past three months. In which of these sources should the student look? [SEP] A. newspapers [SEP] B. magazines [SEP] C. science textbooks [SEP] D. science journals

Answer: D


What is taken in by the leaves of a tree so it can make its own food? [SEP] A. oxygen [SEP] B. sugar [SEP] C. sunlight [SEP] D. water

Answer: C


Radio signal interruption sometimes causes a humming or buzzing sound. These sounds are most likely caused by [SEP] A. balanced forces. [SEP] B. longitudinal waves. [SEP] C. gravitational forces. [SEP] D. electromagnetic waves.

Answer: D


Students planned an investigation that included adding a quantity of vinegar to a small amount of baking soda. Which is the best tool to measure the volume of the liquid vinegar used in the investigation? [SEP] A. pan balance [SEP] B. spring scale [SEP] C. meter stick [SEP] D. graduated cylinder

Answer: D


Garrett collected some large rocks from a stream near his home. He measured the rocks on a balance. When he records the mass of the rocks, which units should Garrett use? [SEP] A. pounds [SEP] B. kilograms [SEP] C. fluid ounces [SEP] D. cubic centimeters

Answer: B


Which of the statements is the most accurate in describing the chemical equation shown below? 2H_{2}(g) + O_{2}(g) -> 2H_{2}O(g) + energy [SEP] A. A solid is produced. [SEP] B. Energy is released. [SEP] C. Energy is absorbed. [SEP] D. Equal numbers of molecules are on both sides of the arrow.

Answer: B


A female dog is having puppies. She has black fur, brown eyes, and a curly tail. She can sit, bark, and roll over on command. Which set of traits can the female dog's puppies inherit? [SEP] A. brown eyes, black fur [SEP] B. fur, roll over on command [SEP] C. brown eyes, sit on command [SEP] D. bark on command, curly tail

Answer: A


Scientists estimate that Maryland contains more than 850 million tons of coal. Coal is most commonly used to produce ___. [SEP] A. electricity [SEP] B. medicine [SEP] C. metals [SEP] D. water

Answer: A


Large populations of tortoises inhabited the Galapagos Islands before humans. When humans settled on the islands and introduced goats, the number of tortoise declined. What is most likely the explanation for the decrease in the tortoise population? [SEP] A. Goats consume tortoise hatchlings. [SEP] B. Goats pollute water sources. [SEP] C. Goats compete with tortoises for vegetation. [SEP] D. Goats contribute to soil erosion.

Answer: C


Hereditary information is transmitted from parents to offspring through [SEP] A. cell division. [SEP] B. genes. [SEP] C. germination. [SEP] D. metamorphosis.

Answer: B


Which device converts kinetic energy into electrical energy? [SEP] A. calculator [SEP] B. generator [SEP] C. electric motor [SEP] D. electromagnet

Answer: B


Which behavior is a learned behavior? [SEP] A. eating with a fork [SEP] B. shivering when it is cold [SEP] C. squinting your eyes in bright light [SEP] D. developing a fever when you are sick

Answer: A


The distance between the Sun and the next closest star, Proxima Centauri, is most accurately measured in [SEP] A. magnitudes. [SEP] B. light years. [SEP] C. perigees. [SEP] D. red shifts.

Answer: B


Which of these uses sound waves to locate underwater objects? [SEP] A. radar [SEP] B. sonar [SEP] C. telescope [SEP] D. microscope

Answer: B


Paleontologists are scientists who study evidence of past life on Earth. Which method do paleontologists most likely use to determine the forms of life that existed millions of years ago? [SEP] A. examine current species of plants and animals [SEP] B. research past species in the library [SEP] C. interview older scientists [SEP] D. examine fossils records

Answer: D


The temperature in a hot star is high enough to pull electrons away from atoms. What state of matter results from this process? [SEP] A. gas [SEP] B. solid [SEP] C. liquid [SEP] D. plasma

Answer: D


Which resource, abundant in Nevada, is nonrenewable? [SEP] A. copper [SEP] B. wind [SEP] C. sunlight [SEP] D. wood

Answer: A


A student reaches one hand into a bag filled with smooth objects. The student feels the objects but does not look into the bag. Which property of the objects can the student most likely identify? [SEP] A. shape [SEP] B. color [SEP] C. ability to reflect light [SEP] D. ability to conduct electricity

Answer: A


An abiotic factor that most influences the organisms living in a salt marsh is [SEP] A. fish. [SEP] B. water. [SEP] C. predators. [SEP] D. grasses.

Answer: B


When oil is burning, the reaction will [SEP] A. only release energy [SEP] B. only absorb energy [SEP] C. neither absorb nor release energy [SEP] D. sometimes release and sometimes absorb energy depending on the oil

Answer: A


Fourth graders are planning a roller-skate race. Which surface would be the best for this race? [SEP] A. gravel [SEP] B. sand [SEP] C. blacktop [SEP] D. grass

Answer: C


Protein is used by the human body to [SEP] A. build strong bones. [SEP] B. absorb vitamins. [SEP] C. repair cells. [SEP] D. provide fiber.

Answer: C


Changes in the weather are important to people living in Alaska. Which two tools best help scientists to share information about weather? [SEP] A. radio and computer [SEP] B. clock and notebook [SEP] C. television and hand lens [SEP] D. microscope and telephone

Answer: A


Which outcome is most likely if a person consumes more Calories than needed for daily activities? [SEP] 1. weight loss [SEP] 2. weight gain [SEP] 3. deficiency disease [SEP] 4. infectious disease

Answer: 2


In a mixture, a magnet is used to separate some particles from sand. The dark particles are most likely made of which element? [SEP] A. sodium [SEP] B. iron [SEP] C. sulfur [SEP] D. copper

Answer: B


A student tosses a ball into the air. Which force causes the ball to fall back to the ground? [SEP] A. gravity [SEP] B. magnetism [SEP] C. mechanical [SEP] D. friction

Answer: A


The gravitational force between two objects depends on the distance between the objects and each object's [SEP] 1. mass [SEP] 2. volume [SEP] 3. pressure [SEP] 4. temperature

Answer: 1


Scientists who have studied global climate changes have found that the average temperature of Earth has risen. There has also been an increase in the accumulation of atmospheric greenhouse gases. What is the goal of the scientific community in collecting this type of data? [SEP] A. to understand how greenhouse gases are related to global warming [SEP] B. to decrease the temperature using fossil fuels [SEP] C. to change public attitude on using natural resources [SEP] D. to increase the amount of ice in the Arctic

Answer: A


Paper chromatography is a process used to separate mixtures of substances into their components. The components are carried by a mobile phase through a stationary phase made of absorbent paper. An investigation analyzed a sample of black ink to determine its components.Which property allows the components to separate? [SEP] A. the solubility of the components in the mobile phase [SEP] B. the evaporation rate of the components at a certain temperature [SEP] C. the magnetic property of the components [SEP] D. the thickness of the paper used as the stationary phase

Answer: A


In one area, a large source of prey for eagles is rabbits. If the number of rabbits suddenly decreases, what effect will it most likely have on the eagles? [SEP] A. Their numbers will increase. [SEP] B. Their numbers will decrease. [SEP] C. They will adapt new behaviors. [SEP] D. They will migrate to new locations.

Answer: B


Moving water in a river is considered a renewable resource because it [SEP] 1. carries dissolved oxygen [SEP] 2. easily erodes sediments [SEP] 3. is made of natural gas [SEP] 4. can be recycled by nature over time

Answer: 4


When studying planetary data, Jackie found some similarities and differences among the planets that make up the solar system. Which generalization is true about the orbits of the major planets in the solar system? [SEP] A. Planetary orbits have the same plane. [SEP] B. Planetary orbits are mostly elliptical in shape. [SEP] C. Planets orbit at the same speed around the Sun. [SEP] D. Planets orbit in different directions around the Sun.

Answer: B


When nitrogen-rich runoff from farms enters a nearby farm, it causes abundant growth of algal mat on the pond surface. As a result, underwater plants in the pond begin to die. Identify the limiting factor that is most responsible for causing the underwater plants to die. [SEP] A. oxygen [SEP] B. sunlight [SEP] C. nitrogen [SEP] D. carbon dioxide

Answer: B


What is the main source of energy for the water cycle? [SEP] A. the Sun [SEP] B. fossil fuels [SEP] C. clouds [SEP] D. the ocean

Answer: A


Which of the following properties of a substance is conserved during thermal expansion? [SEP] A. mass [SEP] B. volume [SEP] C. shape [SEP] D. distance between particles

Answer: A


Trees use narrow tubes to transport water upward. Which property of water allows the water to rise in these narrow tubes? [SEP] A. high vapor pressure [SEP] B. high boiling point [SEP] C. cohesion of molecules [SEP] D. net charge of molecules

Answer: C


Which pair together could cause a rainbow? [SEP] A. Fog and clouds [SEP] B. Rain and snow [SEP] C. Clouds and ice [SEP] D. Sunshine and rain

Answer: D


The property of matter that resists changes in motion is called [SEP] A. inertia. [SEP] B. friction. [SEP] C. gravity. [SEP] D. weight.

Answer: A


Monarch butterflies use milkweed plants during all of their life stages. Milkweed plants grow in open areas, such as grasslands and wetlands. They also often grow between row crops. Given this information, which of these biotechnologies would pose the greatest threat to monarch butterflies? [SEP] A. development of new antibiotics [SEP] B. development of new herbicides [SEP] C. development of disease-resistant crops [SEP] D. development of insect-resistant crops

Answer: B


In the past, Native American Indians buried dead fish along with corn seeds. This technique was used because the decomposing dead fish would [SEP] 1. provide nutrients for the growing corn plant [SEP] 2. eliminate the need for weeding around the corn plant [SEP] 3. release oxygen for use by the corn plant [SEP] 4. supply all the water needed by the corn plant

Answer: 1


Earth is composed of layers of material with different properties. Which of the following is most likely to be in constant motion? [SEP] A. core [SEP] B. mantle [SEP] C. oceanic crust [SEP] D. continental crust

Answer: B


Which mechanism helps carbon to cycle from the atmosphere to living organisms? [SEP] A. tissue decomposition [SEP] B. cellular respiration [SEP] C. photosynthesis [SEP] D. transpiration

Answer: C


A city has an outbreak of a disease that affects an unusually large portion of its population at the same time. Which term best describes the outbreak? [SEP] A. pandemic [SEP] B. plague [SEP] C. epidemic [SEP] D. infection

Answer: C


In which structure is the Sun located? [SEP] A. Milky Way Galaxy [SEP] B. Andromeda Galaxy [SEP] C. Cat's Eye Nebula [SEP] D. Horseshoe Nebula

Answer: A


Removing waste from the body is the primary function of which body system? [SEP] A. excretory [SEP] B. nervous [SEP] C. circulatory [SEP] D. skeletal

Answer: A


Which discovery revealed that the universe contains many structures composed of millions of stars? [SEP] A. novas [SEP] B. galaxies [SEP] C. black holes [SEP] D. solar systems

Answer: B


If a tall tree falls over in a crowded forest, which resource becomes available to the surrounding plants? [SEP] A. air [SEP] B. soil [SEP] C. water [SEP] D. sunlight

Answer: D


What best describes the mantle of Earth? [SEP] A. a thin layer that is located on the surface [SEP] B. a solid layer made of iron and nickel [SEP] C. the largest layer between the crust and outer core [SEP] D. the smallest layer that is made up of molten rock

Answer: C


When Javier exercises, his muscle cells need more oxygen. Which would help Javier's muscle cells receive more oxygen? [SEP] A. decreasing his respiration rate [SEP] B. increasing his perspiration rate [SEP] C. increasing the rate his heart beats [SEP] D. decreasing the rate his blood flow

Answer: C


Which process has most likely occurred when new traits appear in a species? [SEP] A. selective breeding [SEP] B. genetic mutation [SEP] C. crossbreeding [SEP] D. cloning

Answer: B


A patient visits the doctor for a checkup and is diagnosed with skin cancer. Which of the following is the most likely cause of this disease? [SEP] A. poor eating and sleeping habits [SEP] B. exposure to ultraviolet rays [SEP] C. a defect in the person's immune system [SEP] D. working with plants and animals

Answer: B


Which of the following forms of energy can travel by vibrating particles of air? [SEP] A. electrical [SEP] B. light [SEP] C. magnetic [SEP] D. sound

Answer: D


A chef uses a metal spoon to stir noodles cooking in a pan. After five minutes, she notices that the thermal energy from the pan has made the spoon [SEP] A. cold. [SEP] B. hot. [SEP] C. wet. [SEP] D. dry.

Answer: B


Which will most likely cause a decrease in predator populations? [SEP] A. an increase in prey populations [SEP] B. a decrease in prey populations [SEP] C. a decrease in decomposers [SEP] D. an increase in producers

Answer: B


A robin catches and eats a cricket. Which statement best describes the roles of each animal? [SEP] A. The robin is the prey and the cricket is the predator. [SEP] B. The robin is the predator and the cricket is the prey. [SEP] C. The robin is the consumer and the cricket is the producer. [SEP] D. The robin is the producer and the cricket is the consumer.

Answer: B


Hookworms live inside the intestines of dogs. As the dog eats, the hookworms consume partially digested food. As a result of this nutrient diversion, the dog can become malnourished and weakened. Which best describes the relationship between the hookworms and the dog? [SEP] A. a parasitic relationship [SEP] B. a mutualistic relationship [SEP] C. a predator-prey relationship [SEP] D. a producer-consumer relationship

Answer: A


The prairie grass ecosystem once had a deep layer of topsoil which was protected by the grasses that covered it. Removal of these grasses for farmland is causing the soil to be eroded mainly by [SEP] A. wind and rain. [SEP] B. animal movement. [SEP] C. crops grown in the soil. [SEP] D. increased temperatures.

Answer: A


When the Northern Hemisphere is tilted toward the Sun, what season is occurring in Australia? [SEP] A. fall [SEP] B. winter [SEP] C. spring [SEP] D. summer

Answer: B


Light waves are arranged in the electromagnetic spectrum by [SEP] A. wavelength and brightness. [SEP] B. speed and color. [SEP] C. brightness and color. [SEP] D. wavelength and frequency.

Answer: D


In order to distinguish fact from opinion, conclusions in experiments should be [SEP] A. recorded on a computer. [SEP] B. presented in bar graphs. [SEP] C. based on verifiable data. [SEP] D. organized in a table.

Answer: C


Pumice is formed when lava from a volcano cools. Which rock type is pumice? [SEP] A. Gaseous rock [SEP] B. Igneous rock [SEP] C. Sedimentary rock [SEP] D. Metamorphic rock

Answer: B


The principle of uniformitarianism states that most of the landscape of Earth was formed slowly and over a long period of time. Which occurrence of Earth is least supported by this principle? [SEP] A. soil development [SEP] B. volcanic eruption [SEP] C. plate movement [SEP] D. fossil formation

Answer: B


Selective breeding has resulted in plants that are resistant to pests and produce a higher yield of fruits and vegetables. Which of these is the most likely disadvantage that can result from this process? [SEP] A. decreased genetic diversity [SEP] B. habitat destruction [SEP] C. overpopulation [SEP] D. increased erosion

Answer: A


A student measured the volume of water in a pan. The student boiled the water for thirty minutes and then measured the volume of the water again. The volume of water most likely [SEP] A. decreased [SEP] B. increased [SEP] C. remained the same

Answer: A


Lori owns a house next to the lake. She uses lots of fertilizer to keep her lawn green. Which impact could fertilizing her lawn have on the lake? [SEP] A. an increase in the algae population [SEP] B. an increase in the fish population [SEP] C. an increase in the mosquito population [SEP] D. an increase in the lake's depth

Answer: A


To compare the hardness of different minerals, it would be BEST to find [SEP] A. the color of the minerals. [SEP] B. which minerals scratch other minerals. [SEP] C. which minerals reflect light most strongly. [SEP] D. the samples that feel smoothest to the touch.

Answer: B


A house is built in a desert, where there is no electricity and very little wind. Which action could lead to operating the electrical appliances in the house that would cause the least amount of environmental pollution? [SEP] A. constructing a small hydroelectric plant [SEP] B. placing solar panels on the roof of the house [SEP] C. using gasoline generators [SEP] D. burning coal or wood

Answer: B


Students are learning about the natural resources in Maryland. One group of students researches information about renewable natural resources in the state. The other group researches information about nonrenewable natural resources in the state. The resources the students investigate include plants, animals, soil, minerals, water, coal, and oil. Which nonrenewable natural resource heats homes? [SEP] A. sunlight [SEP] B. aluminum [SEP] C. natural gas [SEP] D. ocean waves

Answer: C


Gregor Mendel was the first to show that organisms had traits that are passed on from parents to the next generation. In order for the scientific community to accept Mendel's discovery, others had to [SEP] A. invent the microscope. [SEP] B. read through his journals. [SEP] C. duplicate the results of his experiments. [SEP] D. invest money in his scientific investigations.

Answer: C


Alicia has lots of old bicycle parts. She wants to build something new with the parts. What is the first thing Alicia should do? [SEP] A. plan the new item [SEP] B. construct the new item [SEP] C. try out the new item [SEP] D. evaluate the new item

Answer: A


Which is a major organ of the nervous system? [SEP] A. brain [SEP] B. stomach [SEP] C. lung [SEP] D. bone

Answer: A


Some students were investigating the relationship between position, time, and speed. The students marked the initial position of a toy car. The students set the car into motion and marked the position of the car each second. Which of these are most appropriate for recording and analyzing the students' data? [SEP] A. a table and a bar graph [SEP] B. a table and a line graph [SEP] C. a pie chart and a bar graph [SEP] D. a pie chart and a line graph

Answer: B


If the number of trees significantly decreases, the atmosphere's level of which gas might significantly increase? [SEP] A. nitrogen [SEP] B. carbon dioxide [SEP] C. carbon monoxide [SEP] D. hydrogen

Answer: B


Which of the following is the best estimate of the number of stars in a typical galaxy? [SEP] A. tens [SEP] B. hundreds [SEP] C. thousands [SEP] D. billions

Answer: D


A company plants trees on a bare hillside. Which of these is the BEST reason for planting the trees? [SEP] A. The trees provide oxygen for the soil. [SEP] B. The trees prevent soil from washing away. [SEP] C. The trees make shade for animals living there. [SEP] D. The trees cause animals to move to other places.

Answer: B


Index fossils help scientists estimate the age of a rock because index fossil species only existed for a relatively short time. What happened to the species that are now used as index fossils? [SEP] A. They became extinct. [SEP] B. They changed their diets. [SEP] C. They hid in marine sediments. [SEP] D. They migrated to new environments.

Answer: A


Feathers, wings, and the hollow bones of birds are examples of [SEP] 1. adaptations for flight [SEP] 2. responses to stimuli [SEP] 3. unnecessary body parts [SEP] 4. reproductive structures

Answer: 1


A student climbs up a rocky mountain trail in Maine. She sees many small pieces of rock on the path. Which action most likely made the small pieces of rock? [SEP] A. sand blowing into cracks [SEP] B. leaves pressing down tightly [SEP] C. ice breaking large rocks apart [SEP] D. shells and bones sticking together

Answer: C


Which of the following heat exchange processes involves the collision of particles? [SEP] A. insulation [SEP] B. conduction [SEP] C. convection [SEP] D. radiation

Answer: B


The most effective way to show a change happening over time is to display your results using a [SEP] A. line graph. [SEP] B. Venn diagram. [SEP] C. pie chart. [SEP] D. flow chart.

Answer: A


The diet of a brown bear includes roots, grasses, berries, nuts, fish, insects, and mammals. Based on this description, in what category is a brown bear? [SEP] A. carnivore [SEP] B. herbivore [SEP] C. omnivore [SEP] D. decomposer

Answer: C


A bracket fungus grows on a dead tree and breaks it down into chemical nutrients. What term best classifies the role of a bracket fungus in this ecosystem? [SEP] A. producer [SEP] B. consumer [SEP] C. parasite [SEP] D. decomposer

Answer: D


The comet Shoemaker-Levy struck the planet Jupiter in July of 1994. The process of a comet striking a planet is an example of a net decrease in kinetic energy. Kinetic energy was ultimately converted into [SEP] A. light. [SEP] B. radiation. [SEP] C. thermal energy. [SEP] D. electromagnetic energy.

Answer: C


An earthquake in the Earth's crust under the ocean releases sound waves. Which statement accurately describes how the sound waves spread? [SEP] A. They spread in all directions away from their source. [SEP] B. They remain trapped near the source by water pressure. [SEP] C. They travel mostly horizontally along the ocean floor. [SEP] D. They travel mostly upward toward the surface of the water.

Answer: A


Which provides the oldest evidence for oxygen accumulation in Earth's atmosphere? [SEP] A. the earliest fossils of animals [SEP] B. the earliest sediments of oxidized rock [SEP] C. impact craters of oxidized-iron asteroids [SEP] D. extensive volcanic calderas of similar age

Answer: B


Louis Pasteur discovered that the bacteria in a substance can be killed by heating the substance for a short period of time. Which of these practices benefited most from Pasteur's discovery? [SEP] A. storing foods for longer periods of time [SEP] B. building ovens and other heating devices [SEP] C. creating medicines that cure infections [SEP] D. transporting living organisms without injuring them

Answer: A


How do traits of animals such as ear shape, nose shape, and hair color most often get passed to offspring? [SEP] A. sexual reproduction [SEP] B. asexual reproduction [SEP] C. adaptation [SEP] D. instinct

Answer: A


Why is the ozone content of the stratosphere important to living organisms? [SEP] A. Ozone absorbs infrared radiation from the Sun. [SEP] B. Ozone absorbs ultraviolet radiation from the Sun. [SEP] C. Ozone is necessary to create oxygen for living things. [SEP] D. Ozone in the atmosphere prevents radiation of heat from Earth.

Answer: B


If an environment becomes warmer and drier, the change that would most likely help a species adapt would be an increase in its [SEP] A. amount of body fat. [SEP] B. amount of body hair. [SEP] C. ability to climb trees. [SEP] D. ability to store water.

Answer: D


Thousands of years ago, several species of large mammals existed in North America. These species became extinct not long after the first human settlement of North America. Which human activity most likely contributed to the extinction of these mammals? [SEP] A. hunting [SEP] B. waterway pollution [SEP] C. habitat destruction [SEP] D. competition for resources

Answer: A


Which of the following is an example of a behavioral adaptation? [SEP] A. hooves of a horse [SEP] B. migration of birds [SEP] C. a spider web [SEP] D. a bee hive

Answer: B


Which two processes could result in the formation of high mountains with well-rounded peaks? [SEP] 1. volcanic eruptions and global warming [SEP] 2. earthquakes and tidal activity [SEP] 3. collision of crustal plates and erosion [SEP] 4. production of greenhouse gases and weathering

Answer: 3


The brown tree snake is a nonnative species found on the South Pacific island of Guam. The brown tree snake population in Guam is so large that it negatively affects the humans there. Which statement best explains why the brown tree snake has flourished in Guam? [SEP] A. There are many animals for food. [SEP] B. There are no natural snake predators. [SEP] C. The climate is ideal for snake reproduction. [SEP] D. The vegetation provides good habitat for hunting.

Answer: B


How are droughts always different from floods? [SEP] A. They have different locations. [SEP] B. They happen in different ecosystems. [SEP] C. They have different amounts of water. [SEP] D. They happen at different times of the year.

Answer: C


Which of the following is a harmful waste material that leaves the blood and travels through the lungs before leaving the body? [SEP] A. CO2. [SEP] B. O2. [SEP] C. H2O. [SEP] D. NaCl.

Answer: A


How are a tree and grass alike? [SEP] A. Both make wood. [SEP] B. Both have roots. [SEP] C. Both need moonlight. [SEP] D. Both have short lives.

Answer: B


What organ system in the human body contains the pituitary gland, hypothalamus gland, and thyroid gland? [SEP] A. reproductive system [SEP] B. excretory system [SEP] C. endocrine system [SEP] D. circulatory system

Answer: C


Which term describes an organism's ability to maintain a stable internal environment? [SEP] 1. reproduction [SEP] 2. extinction [SEP] 3. locomotion [SEP] 4. regulation

Answer: 4


Which of the following can provide the human body with long-term immunity against some diseases? [SEP] A. antibiotics [SEP] B. vitamins [SEP] C. vaccines [SEP] D. red blood cells

Answer: C


Which event is most likely to increase the genetic variation in a population of organisms? [SEP] A. improved hunting techniques [SEP] B. greater environmental stress [SEP] C. increased immigration [SEP] D. introduced predators

Answer: C


Where would animals and plants be most affected by a flood? [SEP] A. low areas [SEP] B. high areas [SEP] C. warm areas [SEP] D. cold areas

Answer: A


Which seismic wave phenomenon, found at structural boundaries, allows scientists to interpret the interior structure of Earth? [SEP] A. refraction of waves [SEP] B. generation of new waves [SEP] C. transformation of transverse waves into longitudinal waves [SEP] D. transformation of mechanical waves into electromagnetic waves

Answer: A


When ice melts, it becomes a [SEP] A. gas. [SEP] B. solid. [SEP] C. liquid. [SEP] D. plasma.

Answer: C


Which combination of letters could be used as a chemical symbol for an element? [SEP] A. BR [SEP] B. Chl [SEP] C. Dy [SEP] D. FeO

Answer: C


How is the stratosphere different from the troposphere? [SEP] A. The clouds in the stratosphere produce more rain. [SEP] B. The air in the stratosphere has a greater density. [SEP] C. The composition of the stratosphere lacks ozone. [SEP] D. The temperature of the stratosphere warms at higher altitude.

Answer: D


If a student gets a chemical splashed into an eye, what is the most appropriate first action to be taken? [SEP] A. wipe it with a paper towel [SEP] B. call 911 for emergency services [SEP] C. have someone go get the school nurse [SEP] D. flush the eye with water at an eyewash station

Answer: D


Which of the following best describes an advantage of using a mass production manufacturing system instead of a custom manufacturing system? [SEP] A. Customers can provide specific feedback to workers. [SEP] B. Workers become skilled in all aspects of assembly. [SEP] C. Goods can be easily modified for customers. [SEP] D. Products can be made at a lower cost.

Answer: D


Which adaptation allows a walrus to stay warm in cold water? [SEP] A. reddish coat [SEP] B. bristly mustache [SEP] C. wrinkled skin [SEP] D. thick layer of blubber

Answer: D


Ninety-nine percent of the mass of an atom is located in [SEP] A. the outermost energy level. [SEP] B. the first energy level. [SEP] C. the electron clouds. [SEP] D. the nucleus.

Answer: D


Which of the following is a common renewable resource found in deserts? [SEP] A. biodiesel [SEP] B. uranium [SEP] C. natural gas [SEP] D. solar energy

Answer: D


Beaver dams can cause floods. This statement shows how [SEP] 1. animal growth is affected by environmental conditions [SEP] 2. animal behavior may affect the environment [SEP] 3. an animal's health depends on its environment [SEP] 4. an animal's development depends on its environment

Answer: 2


A scientist crosses a red-flowered plant with a white-flowered plant, and all offspring have red flowers. What will most likely result if these red-flowered offspring are crossed with white-flowered plants? [SEP] A. All of the offspring will have red flowers. [SEP] B. All of the offspring will have white flowers. [SEP] C. The offspring will have either red or white flowers. [SEP] D. The offspring will have neither red nor white flowers.

Answer: C


Genetically modified plants with new characteristics have been produced through genetic engineering methods. What impacts have resulted from the use of genetically modified plants? [SEP] A. decreases in farm production [SEP] B. decreases in corn, soybean, cottonseed, and canola oils [SEP] C. increases in time required to plant, grow, and harvest crops [SEP] D. increases in resistance to herbicides, insects, and viral diseases

Answer: D


Which best explains the importance of nitrogen in the cycling of energy and matter? [SEP] A. Nitrogen increases protein production in plants. [SEP] B. Nitrogen decreases protein production in plants. [SEP] C. Nitrogen decreases the effectiveness of photosynthesis. [SEP] D. Nitrogen increases the effectiveness of photosynthesis.

Answer: A


Which of these mixtures would be easiest to separate? [SEP] A. Fruit salad [SEP] B. Powdered lemonade [SEP] C. Hot chocolate [SEP] D. Instant pudding

Answer: A


If you wanted to be able to look at the stars, the planets, and the Moon more closely, what should you use? [SEP] A. Telescope [SEP] B. Periscope [SEP] C. Microscope [SEP] D. Magnifying glass

Answer: A


Which of the following is a correct food chain? [SEP] A. human -> corn -> cow [SEP] B. corn -> human -> cow [SEP] C. corn -> cow -> human [SEP] D. cow -> human -> corn

Answer: C


Which of these is directly formed as a result of weathering and erosion? [SEP] A. crystals [SEP] B. sediments [SEP] C. igneous rocks [SEP] D. metamorphic rocks

Answer: B


Most underground caves are formed by the action of water on [SEP] A. granite [SEP] B. limestone [SEP] C. sandstone [SEP] D. shale

Answer: B


A group of students is taking a hike along a stream channel. One student picks up a rock from the stream and notices that the rock is very smooth and round. Which type of weathering most likely shaped the rock? [SEP] A. abrasion [SEP] B. exfoliation [SEP] C. fracturing [SEP] D. oxidation

Answer: A


Which of the following is most likely to make a rock crack and crumble? [SEP] A. dew evaporating on the rock [SEP] B. leaves decaying on the rock [SEP] C. snow melting in a crack in the rock [SEP] D. water freezing in a crack in the rock

Answer: D


Which is the most likely reason why scientific theories change? [SEP] A. public opinions change [SEP] B. retiring scientists are replaced [SEP] C. more money is spent on science [SEP] D. scientists make new observations

Answer: D


A plant produces tiny plants around the edges of its leaves. When these tiny plants fall to the ground, they take root and become new plants. This process is an example of [SEP] 1. sexual reproduction [SEP] 2. asexual reproduction [SEP] 3. evolution [SEP] 4. extinction

Answer: 2


A function of a plant's roots is to [SEP] A. protect the plant. [SEP] B. absorb water and minerals. [SEP] C. remove waste products. [SEP] D. take in food for the plant.

Answer: B


In order for sediments to become rock, the sediments are generally [SEP] A. mixed with organic material. [SEP] B. returned to their origins. [SEP] C. compacted. [SEP] D. liquefied.

Answer: C


When bedrock in Massachusetts is examined, it often appears scraped and polished. Which of the following most likely caused the bedrock to appear scraped and polished? [SEP] A. crustal deformation [SEP] B. frequent earthquakes [SEP] C. glacial movement [SEP] D. volcanic eruptions

Answer: C


Endothermic reactions are reactions that require more energy to start than they give off in the products. Which statement describes an endothermic reaction? [SEP] A. It gives off heat energy and is hot to the touch. [SEP] B. It absorbs heat energy and is cold to the touch. [SEP] C. It gives off light energy and produces visible light. [SEP] D. It gives off water and is wet to the touch.

Answer: B


Which pair of English and metric units has most nearly the same value? [SEP] A. liter and quart [SEP] B. gram and ounce [SEP] C. kilogram and pound [SEP] D. kilometer and mile

Answer: A


Students are studying the classifications of stars and they learned that the majority of stars are similar to the Sun. What can the students conclude knowing that most of the stars in the galaxy are like the Sun? [SEP] A. Most of the stars will become black holes. [SEP] B. Most of the stars are main sequence stars. [SEP] C. Most of the stars are protostars. [SEP] D. Most of the stars are red giants.

Answer: B


Mosquitoes have adapted to detect carbon dioxide using certain sensory nerves. Mosquitoes instinctually move toward greater concentrations of carbon dioxide. What is the importance of this adaptation? [SEP] A. It helps mosquitoes find food. [SEP] B. It helps mosquitoes find mates. [SEP] C. It helps mosquitoes find clean air. [SEP] D. It helps mosquitoes find shelter.

Answer: A


Which unit can be used to describe an object's length? [SEP] A. grams [SEP] B. minutes [SEP] C. liters [SEP] D. meters

Answer: D


Meteorologists categorize hurricanes based on the Saffir-Simpson scale. The scale measures the intensity and destructive potential of hurricanes. Which factor has the most significant effect on the strength of a hurricane? [SEP] A. the initial speed of a hurricane [SEP] B. the direction that the hurricane rotates [SEP] C. the number of hurricanes that form in a year [SEP] D. the temperature of the water below the hurricane

Answer: D


Multicellular organisms grow in size by producing more [SEP] A. cells. [SEP] B. organs. [SEP] C. heart muscle. [SEP] D. chlorophyll.

Answer: A


Which a molecular process found only in retroviruses? [SEP] A. reverse translation [SEP] B. translation [SEP] C. reverse transcription [SEP] D. transcription

Answer: C


A group of students are observing a fish tank for a school assignment. The group is to share the observations with the class. Which statement about observations is true? [SEP] A. Observations should always be recorded. [SEP] B. Observations should be collected only once. [SEP] C. Observations are only collected by scientists. [SEP] D. Observations are always correct if used in a chart.

Answer: A


Sodium bicarbonate (NaHCO_{3}) is commonly known as baking soda. Sodium bicarbonate is a white solid that can dissolve in water. Under the proper conditions, sodium bicarbonate can release carbon dioxide (CO_{2}) gas. Which of the following is not a physical property of sodium bicarbonate? [SEP] A. It is white. [SEP] B. It is a solid. [SEP] C. It can dissolve in water. [SEP] D. It releases carbon dioxide.

Answer: D


To help it survive, an organism has a capsule, endospore, and pili. To which group does this organism belong? [SEP] A. bacteria [SEP] B. mollusk [SEP] C. insect [SEP] D. reptile

Answer: A


What advantage is gained by using radio telescopes as opposed to optical telescopes? [SEP] A. viewed images are clearer [SEP] B. operation is less complex [SEP] C. ability to see through clouds and dust [SEP] D. ability to take up less space

Answer: C


The process by which organisms with favorable variations reproduce at higher rates than those without such variations is [SEP] A. disruptive selection. [SEP] B. natural selection. [SEP] C. sexual selection. [SEP] D. directional selection.

Answer: B


Competition is most likely to occur between which two organisms? [SEP] 1. deer and butterflies [SEP] 2. owls and bacteria [SEP] 3. goldfish and rabbits [SEP] 4. grass and strawberry plants

Answer: 4


Some animals, such as squirrels, may bury acorns. Which of the following is most likely to happen to the acorns after they have been buried? [SEP] A. The acorns will be carried away by the wind. [SEP] B. The acorns will attach to another organism. [SEP] C. The acorns will have a chance to sprout. [SEP] D. The acorns will turn into fossils.

Answer: C


Why are most fossils found in sedimentary rocks? [SEP] A. Sedimentary rocks are not very old. [SEP] B. Organisms live only in areas with sedimentary rock. [SEP] C. Organisms can be preserved in sedimentary rock. [SEP] D. Sedimentary rocks are found only at the surface of the ground.

Answer: C


Which model is used by scientists to determine the properties of elements? [SEP] 1. a Punnett square [SEP] 2. the Periodic Table [SEP] 3. a pedigree chart [SEP] 4. the rock cycle

Answer: 2


Life is more likely to be found on a planet whose atmosphere contains abundant [SEP] A. neon. [SEP] B. oxygen. [SEP] C. hydrogen. [SEP] D. sulfur dioxide.

Answer: B


Approximately how long does Earth take to complete its orbit around the Sun? [SEP] A. one day [SEP] B. one month [SEP] C. one year [SEP] D. one century

Answer: C


A student describes a substance as lacking a definite shape. The description also states that the particles of matter are close to each other but still able to flow past each other. Which type of substance is the student most likely describing? [SEP] A. solid [SEP] B. liquid [SEP] C. mixture [SEP] D. compound

Answer: B


Electron transport in mitochondria results in a chemiosmotic gradient of which particle across the mitochondrial membrane? [SEP] A. ADP [SEP] B. ATP [SEP] C. protons [SEP] D. neutrons

Answer: C


At science conventions, scientists present their research, and members of the audience can discuss or ask questions about the research. The main value of these science conventions is that they allow scientists to [SEP] A. see new places. [SEP] B. find money for projects. [SEP] C. practice public speaking. [SEP] D. exchange their ideas.

Answer: D


When a boy stands in a field in the sunlight, he usually is able to see his [SEP] A. weight [SEP] B. temperature [SEP] C. reflection [SEP] D. shadow

Answer: D


In the human body, which system functions primarily to defend the body against disease? [SEP] A. digestive [SEP] B. immune [SEP] C. nervous [SEP] D. respiratory

Answer: B


The moon goes through phases as it revolves around Earth. During which phase of the moon would it be possible for a solar eclipse to occur? [SEP] A. new moon [SEP] B. full moon [SEP] C. waning [SEP] D. waxing

Answer: A


Which of these is the most common result of greenhouse gases altering the atmosphere of Earth? [SEP] A. an increase in the air temperature [SEP] B. a decrease in the air density [SEP] C. an increase in the intensity of visible light [SEP] D. a decrease in the thickness of the ozone layer

Answer: A


A student was taking notes while the teacher was discussing cells. Which of these is a statement that the teacher most likely made? [SEP] A. Most cells have the same shape. [SEP] B. The shape of a cell depends upon its function. [SEP] C. Cells that carry information are round and disk-shaped. [SEP] D. Blood cells that move through the body are long and thread-like.

Answer: B


What goal does taxonomy accomplish? [SEP] A. explains the differences between living organisms [SEP] B. classifies living organisms into groups [SEP] C. predicts the types of undiscovered organisms [SEP] D. establishes relationships of organisms with their habitats

Answer: B


The fusion reaction that fuels the Sun converts hydrogen into [SEP] A. carbon. [SEP] B. iron. [SEP] C. neon. [SEP] D. helium.

Answer: D


The main function of hormones in the human body is to [SEP] 1. identify and destroy microbes [SEP] 2. regulate body functions [SEP] 3. transport blood to cells [SEP] 4. store energy

Answer: 2


Which gas, when condensed into its liquid state in the atmosphere, forms clouds? [SEP] A. methane [SEP] B. nitrogen [SEP] C. water vapor [SEP] D. carbon dioxide

Answer: C


Fertilizers added by farmers to the soil contain high amounts of nitrates. How do fertilizers affect the nitrogen cycle? [SEP] A. More nitrates are available for plants to absorb. [SEP] B. More nitrates are available for animals to eat. [SEP] C. More nitrogen gas is released into the atmosphere. [SEP] D. More nitrogen is converted by bacteria into nitrates.

Answer: A


A scientist is comparing two body cells of a multicellular organism. Which of the following is most likely identical? [SEP] A. shape of cell walls [SEP] B. number of mitochondria [SEP] C. shape of cell membranes [SEP] D. number of chromosomes

Answer: D


Organisms that consume wastes to obtain the nutrients they need to survive are classified as [SEP] 1. decomposers [SEP] 2. herbivores [SEP] 3. predators [SEP] 4. producers

Answer: 1


In the 1600s, Galileo Galilei studied the moons of Jupiter. What did Galileo do to make better observations? [SEP] A. invented the microscope [SEP] B. wrote a book about the planets [SEP] C. created a model of the solar system [SEP] D. made improvements to the telescope

Answer: D


Which of these provides the best evidence that Earth's crust is divided into tectonic plates? [SEP] A. the distribution of water on Earth's surface [SEP] B. the distribution of biomes on Earth's surface [SEP] C. the distribution of rock types on Earth's surface [SEP] D. the distribution of earthquakes on Earth's surface

Answer: D


What causes the soil in a flood plain to be generally rich in nutrients? [SEP] A. constantly flowing water [SEP] B. many fish in the river [SEP] C. new soil deposited by the river [SEP] D. warm water from an ocean

Answer: C


Which characteristic is common to all reptile species? [SEP] A. endothermic (warm-blooded) [SEP] B. slimy skin [SEP] C. ectothermic (cold-blooded) [SEP] D. hairy skin

Answer: C


Scientists working for a company are testing a new medicine that they think will help heal damaged tissue. In which part of the company are the scientists working? [SEP] A. distribution [SEP] B. mass marketing [SEP] C. public relations [SEP] D. research

Answer: D


Most of Earth's surface is covered by [SEP] A. sand [SEP] B. trees [SEP] C. water [SEP] D. mountains

Answer: C


The chemical equation below shows reactants and products. 6CO_{2} + 12H_{2}O + light + enzymes -> C_{6}H_{12}O_{6} + 6O_{2} + 6H_{2}O Which statement is best supported by analyzing this equation? [SEP] A. CO_{2} is made from the chemical reaction. [SEP] B. No new compounds are made from this reaction. [SEP] C. O_{2}, oxygen gas, is needed to make the reaction start. [SEP] D. The atoms rearrange in the chemical reaction so that C_{6}H_{12}O_{6}, glucose, is made.

Answer: D


In a desert environment, cactus wrens often build their nests in cholla cacti to avoid predators. This behavior does not hurt the cacti. Which type of relationship do cactus wrens and cholla cacti demonstrate? [SEP] A. competitive [SEP] B. commensalism [SEP] C. mutualism [SEP] D. parasitism

Answer: B


The Davis Mountains in West Texas used to be taller than they are now. Which of the following conditions most likely caused the mountains to become shorter over time? [SEP] A. Heat and pressure [SEP] B. Soil deposition [SEP] C. Rain and wind [SEP] D. River formation

Answer: C


Photosynthesis is the process that converts carbon dioxide and water into [SEP] A. carbon and oxygen. [SEP] B. sugar and hydrogen. [SEP] C. sugar and oxygen. [SEP] D. nitrogen and carbon.

Answer: C


Which statement best describes the organization of the Periodic Table of the Elements? [SEP] A. All gases are grouped together. [SEP] B. Gases easily form compounds with other elements. [SEP] C. Elements within a group have similar properties. [SEP] D. Elements within a period have the same number of electrons.

Answer: C


Signs in many stores and restaurants warn that microwaves are in use. What is the main reason for this warning? [SEP] A. Some people do not like food cooked in microwave ovens. [SEP] B. Microwaves sometimes affect people's sense of sight. [SEP] C. Microwaves sometimes cause hair or teeth to fall out. [SEP] D. Some people have pacemakers that may be affected by microwaves.

Answer: D


A scientist studies the remains of two extinct animals to learn more about how they lived. She determines that one animal was a carnivore and the other was an herbivore. Which of the following did the scientist most likely compare to make this conclusion? [SEP] A. the number of bones in the animals [SEP] B. the size of the animals [SEP] C. the body covering of the animals [SEP] D. the skull of the animals

Answer: D


Human actions can change the rate at which soil erodes. Which of the following would most likely slow the rate of soil erosion? [SEP] A. applying nitrogen-rich fertilizers [SEP] B. keeping grasses trimmed short [SEP] C. building houses on stilts [SEP] D. planting trees along cliffs

Answer: D


Which ability is the most useful for making observations? [SEP] A. senses [SEP] B. memory [SEP] C. creativity [SEP] D. imagination

Answer: A


Sterling silver is a combination of silver and copper. Which of the following is also a combination of two or more metals? [SEP] A. aluminum. [SEP] B. lead. [SEP] C. gold. [SEP] D. brass.

Answer: D


The cows in a rancher's herd of cattle have been selectively bred to produce milk. Which of the following will cause the next generation of cows to receive the trait for producing large quantities of milk? [SEP] A. nutrients in the cows' food [SEP] B. essential minerals in the cows' water [SEP] C. electrical impulses in the cows' brains [SEP] D. information in the cows' chromosomes

Answer: D


What is the correct explanation for why we have day and night on Earth? [SEP] A. The Sun orbits around the Earth. [SEP] B. Earth orbits around the Sun. [SEP] C. Earth turns on its axis. [SEP] D. The Sun turns on its axis.

Answer: C


The body maintains equilibrium through a series of messages called a feedback mechanism. What organ releases hormones that maintain balanced glucose levels? [SEP] A. liver [SEP] B. blood [SEP] C. fat cells [SEP] D. pancreas

Answer: D


Environmental organizations have asked businesses to take action to reduce waste. Which of the following changes could a business make in order to become more “environmentally friendly”? [SEP] A. Purchase only recycled paper and paper products. [SEP] B. When making photocopies, print on only one side of the paper. [SEP] C. Purchase wood products manufactured only in other countries. [SEP] D. When packing boxes, use Styrofoam™ filler instead of old newspapers.

Answer: A


The sound heard when a piano key is hit is caused by [SEP] A. vibration. [SEP] B. refraction. [SEP] C. momentum. [SEP] D. acceleration.

Answer: A


Wolves kill many elk every year and often attack old, sick, and injured members of a herd. Which of the following best describes the role of the wolves in the wolf-elk relationship? [SEP] A. competitor [SEP] B. host [SEP] C. parasite [SEP] D. predator

Answer: D


Which of the following is produced when sugar is digested in an animal cell? [SEP] A. carbon dioxide. [SEP] B. chlorophyll. [SEP] C. oxygen. [SEP] D. sunlight.

Answer: A


Which of these groups contains single-celled organisms? [SEP] A. birds [SEP] B. plants [SEP] C. fungus [SEP] D. animals

Answer: C


Students studying rocks notice that in a particular location there are many igneous rocks that are very similar. This observation best supports which statement? [SEP] A. A nearby volcano is tall. [SEP] B. A nearby volcano is inactive. [SEP] C. A nearby volcano is about to erupt. [SEP] D. A nearby volcano had once been active.

Answer: D


Shale is a sedimentary rock that can be metamorphosed into slate by [SEP] A. cementation. [SEP] B. chemical weathering. [SEP] C. sedimentation. [SEP] D. increased pressure.

Answer: D


Plants need iron to grow. What parts of plants take in iron? [SEP] A. roots [SEP] B. flowers [SEP] C. stems [SEP] D. leaves

Answer: A


Which of the following is the best observation of the refraction of light? [SEP] A. Looking at oneself in a mirror [SEP] B. Looking at a shadow of an object [SEP] C. Viewing an object through an open window [SEP] D. Viewing an object partially in water

Answer: D


A group of students investigated the effect of water temperature on the gill movements of goldfish. The students tested water temperatures from 20°C to 10°C at 2-degree intervals. The data showed that as water temperature decreased, the average number of gill movements per minute by the goldfish also decreased. Which type of display is BEST used to show this relationship? [SEP] A. a bar graph [SEP] B. a pie chart [SEP] C. a line graph [SEP] D. a tally chart

Answer: A


The directions for making a protein [SEP] A. result in DNA. [SEP] B. are carried by DNA. [SEP] C. result in amino acids. [SEP] D. are carried by amino acids.

Answer: B


Denise was driving east over a hill in the afternoon, shortly after a rain shower. Suddenly the sun broke through the clouds, and she saw a rainbow ahead of her. Which of the following made the rainbow possible? [SEP] A. Sunlight can be separated into all the colors of the rainbow. [SEP] B. Water reflects sunlight like a mirror to make it look colored. [SEP] C. Overhead black clouds reflect in puddles to cause a mirage. [SEP] D. Air pollution causes the sky to look colored under these conditions.

Answer: A


Rhea is a moon of Saturn. Which of these facts about Rhea best indicates that it does not have a water cycle in which water changes state? [SEP] A. Its radius is 765 km. [SEP] B. Its density is about 1.3 kg/m3. [SEP] C. Its period of rotation is about 4.5 Earth days. [SEP] D. Its temperature is between -174°C and -220°C.

Answer: D


Which two factors determine the gravitational attraction between two objects? [SEP] 1. time and temperature [SEP] 2. shape and orbital speed [SEP] 3. color and hardness [SEP] 4. mass and distance apart

Answer: 4


When a red bull (RR) is bred with a white cow (WW), a roan calf (RW) is sometimes produced. If a roan bull (RW) is bred with a roan cow (RW), what is the most likely outcome of the offspring? [SEP] A. 1 red, 1 white, and 2 roan [SEP] B. 0 red, 1 white, and 3 roan [SEP] C. 2 red, 2 white, and 0 roan [SEP] D. 0 red, 0 white, and 4 roan

Answer: A


Which adaptive feature most helps a baby jaguar survive the first few weeks of life? [SEP] A. the ability to roar [SEP] B. the ability to hunt [SEP] C. a diet of land mammals [SEP] D. being born during spring months

Answer: D


Frank needs to move a box by sliding it across the floor. Which two factors will most strongly affect how hard Frank needs to push the box? [SEP] A. The density of the box material and the hardness of the floor [SEP] B. The thickness of the box material and the hardness of the floor [SEP] C. The total mass of the box and the friction between the box and the floor [SEP] D. The total height of the box and the distance between his hands and the floor

Answer: C


An ocean, a forest, and a grassy meadow are each examples of a complete ecosystem. Complete ecosystems contain only [SEP] A. animals. [SEP] B. rocks and water. [SEP] C. living and nonliving things. [SEP] D. populations of plants and animals.

Answer: C


The Great Basin in Nevada is characterized by uplifted, tilted blocks forming mountain ranges and downthrown blocks forming basins. What rock type is MOST likely to form in the basins? [SEP] A. metamorphic [SEP] B. sedimentary [SEP] C. intrusive igneous [SEP] D. extrusive igneous

Answer: B


As the human population increases, more fossil fuels are being used. The burning of fossil fuels produces greenhouse gases. How might humans reduce greenhouse gases? [SEP] A. Buy cars that use gasoline. [SEP] B. Build power plants that use coal. [SEP] C. Use renewable resources to generate power. [SEP] D. Use nonrenewable resources to generate power.

Answer: C


Which situation would most likely cause an object to travel in a circular motion? [SEP] A. one force acting on the object in the opposite direction of the motion [SEP] B. two forces acting on the object in the same direction as the motion [SEP] C. one force acting on the object perpendicular to the direction of the motion [SEP] D. two forces acting on the object in different directions to the motion

Answer: C


Which of the following does not give an example of how sparrows use resources in their environment to survive? [SEP] A. Sparrows breathe air. [SEP] B. Sparrows drink water. [SEP] C. Sparrows use the sun for food. [SEP] D. Sparrows use plants for shelter.

Answer: C


Henry and Emily are building a tree house. Which tool should be used to measure the height of the door? [SEP] A. hammer [SEP] B. meter stick [SEP] C. balance [SEP] D. stopwatch

Answer: B


Windy, cloudy, rainy, and cold are words that help describe [SEP] A. evaporation [SEP] B. deposition [SEP] C. matter [SEP] D. weather

Answer: D


All these statements concerning galaxies are accurate except [SEP] A. They contain millions of stars. [SEP] B. Most can be seen without a telescope. [SEP] C. They are millions of light-years apart. [SEP] D. Space contains several billion galaxies.

Answer: B


Hydrogen gas and oxygen gas combine to form water. Which would be a more concise way of expressing what happens in this chemical reaction? [SEP] A. write a chemical formula [SEP] B. write a chemical equation [SEP] C. describe the rearrangement of the atoms [SEP] D. describe the procedure for creating this change

Answer: B


What safety equipment should be taken on all field trips? [SEP] A. gloves [SEP] B. fire extinguisher [SEP] C. first-aid kit [SEP] D. goggles

Answer: C


The surface gravity of Pluto is the weakest of the nine planets because Pluto [SEP] A. has the lowest temperature. [SEP] B. has the smallest mass. [SEP] C. rotates the slowest. [SEP] D. is farthest from the Sun.

Answer: B


If a class wants to measure the speed of a bicycle during an outdoor lab exercise, which two devices would be most useful? [SEP] A. stopwatch and camera [SEP] B. binoculars and tape measure [SEP] C. binoculars and camera [SEP] D. stopwatch and tape measure

Answer: D


When sunlight shines on a plant, its leaves [SEP] A. make food. [SEP] B. absorb water. [SEP] C. produce seeds. [SEP] D. take in oxygen.

Answer: A


Toads lay their eggs in ponds. Tadpoles hatch from the eggs and eat the plants floating in the pond. Which resource is most important for toads to survive? [SEP] A. grass [SEP] B. rocks [SEP] C. trees [SEP] D. water

Answer: D


Which structure surrounds and protects an animal cell? [SEP] A. Nucleus [SEP] B. Vacuole [SEP] C. Cytoplasm [SEP] D. Cell membrane

Answer: D


A ball is thrown straight up. Which statement best describes the motion of the ball while the ball is at the maximum height? [SEP] A. The speed and acceleration are constant. [SEP] B. The velocity is zero, and the acceleration is constant. [SEP] C. The speed and acceleration are changing. [SEP] D. The velocity is zero, and the acceleration is changing.

Answer: B


Which organ is most responsible for oxygen entering the blood stream? [SEP] A. nose [SEP] B. trachea [SEP] C. bronchi [SEP] D. lungs

Answer: D


Why is a healthy diet important? [SEP] A. It maintains a constant body temperature. [SEP] B. It prevents damage to internal organs. [SEP] C. It makes oxygen for all the cells in the body. [SEP] D. It supplies the body’s needs for growth and energy.

Answer: D


In the human body, the breaking down of food into simple substances occurs in the [SEP] A. digestive system. [SEP] B. excretory system. [SEP] C. circulatory system. [SEP] D. respiratory system.

Answer: A


Which of the following processes is an important part of star formation? [SEP] A. nuclear fusion [SEP] B. nuclear fission [SEP] C. molecular fusion [SEP] D. molecular fission

Answer: A


Carlos puts a new battery into a radio. What does the battery supply to the radio that makes it turn on? [SEP] A. friction [SEP] B. electricity [SEP] C. a sound wave [SEP] D. a magnetic field

Answer: B


What may form as a direct result of a star collapsing? [SEP] A. constellation [SEP] B. galaxy [SEP] C. protostar [SEP] D. supernova

Answer: D


A shoe manufacturer randomly selects 10% of the production from each shift. Each of these shoes is checked to ensure that it is correctly made. What is this process called? [SEP] A. quality control [SEP] B. product distribution [SEP] C. production selection [SEP] D. research and development

Answer: A


Some materials are electrical conductors. Which material best conducts electricity? [SEP] A. copper [SEP] B. plastic [SEP] C. rubber [SEP] D. wood

Answer: A


Angela wants to report daily weather conditions. In which unit should Angela record the air temperature? [SEP] A. degrees Celsius [SEP] B. centimeters [SEP] C. milliliters [SEP] D. grams

Answer: A


Which organisms use the energy from the remains of dead animals and recycle the nutrients back into the environment? [SEP] A. producers [SEP] B. herbivores [SEP] C. omnivores [SEP] D. decomposers

Answer: D


Which is the first step in a design process? [SEP] A. Revise the solution. [SEP] B. Describe the problem. [SEP] C. Test the possible solutions. [SEP] D. Identify possible solutions.

Answer: B


What type of chemical reaction occurs when the body breaks down fats and sugars that supply it with energy? [SEP] A. endothermic [SEP] B. exothermic [SEP] C. electrical [SEP] D. physical

Answer: B


Intense heat and pressure in Earth's crust can change sandstone into quartzite. During this metamorphosis, many properties of these rocks change. Which property of these rocks will most likely remain the same? [SEP] A. mass [SEP] B. volume [SEP] C. crystal structure [SEP] D. particle shape

Answer: A


How do decomposers obtain their food? [SEP] 1. hunting and killing prey for food [SEP] 2. changing carbon dioxide and water into food [SEP] 3. absorbing food from dead organisms [SEP] 4. producing food from oxygen and sunlight

Answer: 3


A ball on a cart is moving at a rate of 2 m/s. The cart suddenly stops and the ball continues to travel in the same direction at the same speed. This is an example of the [SEP] A. law of gravity. [SEP] B. first law of motion. [SEP] C. second law of motion. [SEP] D. third law of motion.

Answer: B


Why is it important to have a large sample size in an investigation? [SEP] A. to be able to compare results [SEP] B. to increase the validity of the data [SEP] C. to form the best conclusion [SEP] D. to ensure the procedure is followed

Answer: B


Burt used a spoon to stir soup that was cooking on his stove. Which spoon will stay the coolest while he stirs? [SEP] A. an iron spoon [SEP] B. an aluminum spoon [SEP] C. a wooden spoon [SEP] D. a silver spoon

Answer: C


Which is a distinction between an epidemic and a pandemic? [SEP] A. the symptoms of the disease [SEP] B. the geographical area affected [SEP] C. the species of organisms infected [SEP] D. the season in which the disease spreads

Answer: B


When two bumper cars collide, some of the kinetic energy of the cars is transformed. Which form of energy is most likely formed as a result of this collision? [SEP] A. electrical [SEP] B. electromagnetic [SEP] C. magnetic [SEP] D. sound

Answer: D


Which statement describes all matter? [SEP] A. All matter contains carbon. [SEP] B. All matter contains oxygen. [SEP] C. All matter is made up of cells. [SEP] D. All matter is made up of atoms.

Answer: D


Carbon dioxide is removed from Earth's atmosphere by [SEP] A. animal respiration. [SEP] B. decaying organisms. [SEP] C. plant photosynthesis. [SEP] D. burning fossil fuels.

Answer: C


A water company uses lab tests on the water supply before sending the water through pipes to people's homes. How do these lab tests help people? [SEP] A. by adding minerals and nutrients to the water [SEP] B. by checking the water to make sure it is safe to drink [SEP] C. by filtering chemicals and organisms out of the water [SEP] D. by stopping harmful substances from entering the water

Answer: B


What safety rule is most important for students to follow when working with acids and bases? [SEP] A. wear nose plugs [SEP] B. put on safety goggles [SEP] C. put away all lab supplies [SEP] D. wear heavy cloth gloves

Answer: B


A person in a dark room looking through a window can clearly see a person outside in the daylight. But a person outside cannot see the person inside. Why does this happen? [SEP] A. There is not enough light being reflected off the person in the room. [SEP] B. Light rays cannot pass through a window twice. [SEP] C. Outside light does not pass through windows. [SEP] D. Sunlight is not as intense as other sources of light.

Answer: A


Many processes on Earth occur at or near tectonic plate boundaries. Which geological events are most common along tectonic plate boundaries? [SEP] A. erosion and deposition [SEP] B. hurricanes and tornadoes [SEP] C. earthquakes and volcanoes [SEP] D. tidal waves and sedimentation

Answer: C