Populations & Resources
What do birds such as eagles and hawks need energy for?
d. all of the above
Will has an aquarium with water, plants, and fish that eat the plants. It is sealed so no material can get in or out, and has glass sides that allow sunlight to come in. The aquarium can also be covered to prevent light from entering.
The amount of carbon in the aquarium’s water started out high. Now, the amount of carbon in the water is decreasing.
Is the aquarium now in sunlight or is it covered? What is happening to the number of energy storage molecules in the plants and fish as a result?
a. The aquarium is now in sunlight, and there are more energy storage molecules in the plants and fish.
b. The aquarium is now in sunlight, and there are fewer energy storage molecules in the plants and fish.
c. The aquarium is now covered so no light can get in, and there are more energy storage molecules in the plants and fish.
d. The aquarium is now covered so no light can get in, and there are fewer energy storage molecules in the plants and fish.
a. The aquarium is now in sunlight, and there are more energy storage molecules in the plants and fish.
Sandra pushed a wooden block and it slid across the floor. The wooden block gradually slowed down and stopped after moving 10 meters.
Why did the block stop moving?
A. The floor exerted a force that is opposite to the direction of the block’s motion.
B. The block ran out of force.
C. The floor absorbs force from the block.
D. All objects stop moving because their natural state is to be still
A. The floor exerted a force that is opposite to the direction of the block’s motion.
a line that connects opposite magnetic poles and represents the strength and direction of the magnetic field
MAGNETIC FIELD LINE
Your friends say that they saw a special nail polish that changes color when it is out in the sun. Can light from the sun cause the nail polish to change color?
A. No. Light is not a physical thing, so it cannot change physical things like nail polish.
B. Yes. Light from the sun can pull energy out of the nail polish, causing it to change color.
C. Yes. The nail polish can take in energy from the light, causing it to change color.
D. No. Light can only change things by warming them up, so it cannot cause the nail polish to change color.
C. Yes. The nail polish can take in energy from the light, causing it to change color.
A population of panthers lives in the southeastern United States. Over 50 years, the size of the panther population in the region increased. What best explains the increase in the size of the panther population?
C. More panthers were born than died
Scientists are studying photosynthesis in a forest ecosystem that has plants, animals, and decomposers (which consume dead things). Which group or groups of organisms in the forest carry out photosynthesis?
At dinner, Hans passed the salt shaker to his sister Jessica by sliding it across the wooden table. The salt shaker gradually slowed down and stopped after moving 12 centimeters.
Why did the salt shaker stop moving?
A. The salt shaker ran out of force.
B. The table exerts a force that is opposite to the salt shaker’s motion.
C. The table absorbs force from the salt shaker.
D. All objects stop moving because their natural state is to be still.
B. The table exerts a force that is opposite to the salt shaker’s motion.
a type of magnet in which the magnetic field is produced by an electric current
ELECTROMAGNET
Dentists use a soft, clay-like material to make a filling for a cavity. The filling stays soft under the light of the dentist’s lamp, but it hardens when the dentist shines an ultraviolet flashlight on it. Why does light from the ultraviolet flashlight harden the filling when light from the lamp does not?
A. Because ultraviolet light carries energy, and light from the lamp does not.
B. Because the filling material can take in energy from ultraviolet light, but not from the light from the lamp.
C. Because ultraviolet light pulls energy out of the filling material, and light from the lamp does not.
D. Because ultraviolet light carries hardening molecules, but light from the lamp does not.
B. Because the filling material can take in energy from ultraviolet light, but not from the light from the lamp.
A population of deer lives in Canada. Over 50 years, the size of the deer population decreased. What best explains the decrease in the size of the deer population?
b. Fewer deer were born than died.
A herd of deer lives in a forest where they eat the leaves of trees. The number of energy storage molecules in the trees and in the deer has increased. What has happened to the amount of carbon in the trees and in the deer?
The amount of carbon in the trees and in the deer . . .
A. has increased.
B. has decreased.
C. has not changed.
D. is not related to the number of energy storage molecules.
B. has decreased.
to apply a force
EXERT
What happens to the energy in a system of magnets when the magnetic force causes two magnets to move?
A. The potential energy in the system increases.
B. The kinetic energy in the system decreases.
C. Some kinetic energy changes into potential energy.
D. Some potential energy changes into kinetic energy.
D. Some potential energy changes into kinetic energy.
Jayden says that the dentist can shine a special light on his teeth that will make his teeth become whiter. Can light change Jayden’s teeth?
A. Yes. Jayden’s teeth can take in energy from the light, causing them to become whiter.
B. Yes. Light can pull energy out of Jayden’s teeth, causing them to become whiter.
C. No. Light can only change things by warming them up, so it cannot cause Jayden’s teeth to become whiter.
D. No. Light is not a physical thing, so it cannot change physical things like teeth.
A. Yes. Jayden’s teeth can take in energy from the light, causing them to become whiter.
A population of sharks lives in the Atlantic Ocean. Over the last 50 years, the size of the shark population increased. What best explains the increase in the size of the shark population?
c. More sharks were born than died.
Lily has an aquarium with water, plants, and fish that eat the plants. The aquarium is sealed so no material can get in or out, and has glass sides that allow light to come in.
The aquarium can also be covered to prevent light from entering. The number of energy storage molecules in the plants and fish started out low, but that number has been increasing over time.
Has the aquarium been in sunlight or has it been covered during this time? What has happened to the carbon in the water?
A. The aquarium has been covered so no light gets in, and there is less carbon in the water.
B. The aquarium has been covered so no light gets in, and there is more carbon in the water.
C. The aquarium has been in sunlight, and there is more carbon in the water.
D. The aquarium has been in sunlight, and there is less carbon in the water
A. The aquarium has been covered so no light gets in, and there is less carbon in the water.
the energy that an object has because it is moving
KINETIC ENERGY
A spaceship is traveling through space. Suddenly, its kinetic energy decreases. What is most likely to be true about the speed of the spaceship?
A. The speed increases as the kinetic energy is converted into speed.
B. The speed decreases as the kinetic energy decreases.
C. The speed remains the same because speed and kinetic energy are not related.
D. The speed increases to make up for the decrease in kinetic energy.
B. The speed decreases as the kinetic energy decreases.
Wei saw a special type of plastic that would melt and become a liquid when it was placed in the sun, but it would not melt when placed under a desk lamp. Why does light from the sun melt the plastic when light from the desk lamp does not?
A. Because the plastic can take in energy from the light from the sun but not from the light from the lamp.
B. Because light from the sun carries heat molecules, and light from the desk lamp does not.
C. Because light from the sun pulls energy out of the plastic, and light from the desk lamp does not.
D. Because the sun gives off a type of light that carries energy, and light from the desk lamp does not.
A. Because the plastic can take in energy from the light from the sun but not from the light from the lamp.
A large population of squirrels lives in a forest. In the last 50 years, the size of the squirrel population has stayed the same. What must be true about the squirrel population during the last 50 years?
Scientists are studying cellular respiration in a jungle ecosystem that has plants, animals, and decomposers (which consume dead things). Which group or groups of organisms in the jungle carry out cellular respiration?
to reach a conclusion using evidence and reasoning
INFER
How does magnetic force affect the energy in a system of magnets when the magnets are released and begin to move?
A. The magnetic force increases the potential energy in the system.
B. The magnetic force decreases the kinetic energy in the system.
C. The magnetic force changes kinetic energy into potential energy.
D. The magnetic force changes potential energy into kinetic energy.
D. The magnetic force changes potential energy into kinetic energy.
Your friend says that he heard about some rocks that would glow when they were put under a certain kind of light. Can light cause rocks to glow?
A. No. Light is not a physical thing, so it cannot change physical things like rocks.
B. No. Light can only change things by warming them up, so it cannot cause the rocks to glow.
C. Yes. Light can pull energy out of the rocks, causing them to glow.
D. Yes. Rocks can take in energy from the light, causing them to glow.
D. Yes. Rocks can take in energy from the light, causing them to glow.