8.L.3.3 Review

Where do plants get most of the energy they need to live and grow?

• water

• soil

• air

• sunlight

In a food pyramid, which best explains why the number of organisms decreases from one trophic level to the next?

• Consumers at the lower level require more energy than the top-level consumers.

• Consumers at the top level require more energy than the lower-level consumers.

• The consumers are feeding on larger organisms that have less energy.

• The consumers are feeding on smaller organisms that have less energy.

Which best explains the role of plants in the carbon cycle?

• Plants take in carbon dioxide released by other organisms.

• Plants take in oxygen and release carbon dioxide.

• Plants take in carbon dioxide and pass it directly to animals.

Which level of a food chain has the most energy?

• producers

• decomposers

• scavengers

• consumers

Which best describes the role of nitrogen-fixing bacteria in the flow of energy?

• They convert carbon dioxide into nitrogen.

• They convert nitrogen into carbon dioxide.

• They convert sunlight and nitrogen into energy-rich sugar molecules.

• They convert atmospheric nitrogen into molecules that other organisms can use.

Through which process do organisms release carbon dioxide into the atmosphere?

• diffusion

• transpiration

• respiration

• photosynthesis

An energy pyramid is illustrated above. Which statement BEST explains the flow of energy as it moves through the different levels?

• Energy decreases as it is lost as heat to the environment.

• Energy increases as it is gained from the environment.

• Energy is unavailable because it is used up by the organisms at Level 1.

• Energy is transferred as it is produced by organisms in the next level.

Which group is not represented in the food web?

• producers

• primary consumers

• secondary consumers

• decomposers

What do the arrows in the food chain indicate about the flow of energy in an ecosystem?

• Energy is continuously recycled by the organisms in an ecosystem.

• Energy flows in one direction in an ecosystem, from producers to consumers.

• More of the available energy in an ecosystem is given to large animals than to small animals.

• Organisms at the end of the food chain receive more energy than those at the beginning.

In this energy pyramid, which organism would most likely be in level 2?

• bird

• fox

• caterpillar

• tree