Unit 7 Review

The primary reason that plants are important for an ecosystem is because they ...

• provide energy for consumers.

• depend on other organisms for shelter.

• break down dead animal matter.

• consume nutrients for energy.

Use the food chain to answer the question that follows.

What would happen if the frogs were suddenly removed from the food chain?

• The grasshopper population would increase.

• The snake population would begin feeding on grasshoppers.

• The owl population would increase.

• The clover population would be unaffected.

Which of these is the primary source of energy in food webs?

**Read this question carefully**

• soil

• sunlight

• producer

• consumer

Using the provided food web, which terms correctly identify the plant, the snake and the bacteria in this food web?

• Plant = Producer; Snake = Consumer; Bacteria = Decomposer

• Plant = Producer; Snake = Decomposer; Bacteria = Consumer

• Plant = Consumer; Snake = Decomposer; Bacteria = Consumer

• Plant = Decomposer; Snake = Consumer; Bacteria = Producer

Earthworms move randomly throughout topsoil. How do earthworms MOST likely affect the topsoil?

• by compacting the topsoil

• by decreasing the fertility of the topsoil

• by adding nutrients to the topsoil

• by removing the materials from the topsoil

Which of the following is MOST likely when a producer is removed from a food chain?

• It impacts the entire food chain.

• It only impacts the next step in the chain.

• It impacts only the next two steps in the chain.

• It will have little effect, as other producers take its place.

Using the energy pyramid shown. Producers are found at the bottom of the pyramid because producers...

• provide energy for consumers.

• have less mass than consumers.

• have fewer species than consumers.

• depend on consumers.

Which gas is released by producers that consumers take in to survive?

• oxygen

• nitrogen

• water vapor

• carbon dioxide

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?

• Their numbers will increase.

• Their numbers will decrease.

• They will show new behaviors.

• They will migrate from new locations.

One year, the oak trees in a park began producing more acorns than usual. The next year, the population of chipmunks in the park also increased. Which BEST explains why there were more chipmunks the next year?

• Shady areas increased.

• Food sources increased.

• Oxygen levels increased.

• Available water increased.