A rabbit depends on various plants in an ecosystem to survive. Which would most likely happen if a drought decreased the plant population?

• The rabbit population would increase.

• The rabbit population would decrease.

• The rabbit population would remain the same.

• The rabbit population would increase, then decrease quickly.

This diagram shows a simple ocean food chain.

algae → fish → seal

Which will most likely occur if the fish population decreases?

• The algae and seal populations will increase.

• The algae and seal populations will decrease.

• The algae population will increase, and the seal population will increase.

• The algae population will increase, and the seal population will decrease.

The diagram below is an aquatic food chain. Which will most likely occur if there is overfishing and a loss of clams?

• The amount of algae would increase and the number of bass would increase.

• The amount of algae would decrease and the number of bass would increase.

• The amount of algae would increase and the number of bass would decrease.

• The amount of algae would decrease and the number of bass would decrease.

This food chain shows organisms in a classroom aquarium. Which would benefit if the snail living in the aquarium were removed?

• algae

• crayfish

• fish

• plant

Why are animals like deer, raccoons, bears, and coyotes sometimes seen in neighborhoods?

• because it is easier to find food

• because they can escape predators

• because their habitats are increasing

• because their habitats are decreasing

The diagram below is a simple grassland food chain.

grass - mouse - snake

If a predator of the snake were introduced to the ecosystem, which would most likely happen

• The grass population would increase.

• The snake population would increase

• The mouse population would increase

• The mouse population would decrease.

This is an aquatic food chain. Which situation will most likely occur if the pond is polluted?

• The tadpole population will decrease while the others will remain the same.

• The algae population will decrease while the others will remain the same.

• The algae, tadpole, and perch populations will decrease.

• The algae, tadpole, and perch populations will increase.

Which is an example of a terrestrial organism relying on an aquatic organism for food?

• Eagles consume fish to survive.

• Birds consume worms to survive.

• Fish consume seaweed to survive.

• Frogs consume flying bugs to survive.

Which food chain below is shown correctly?

• 
• 
• 

The diagram below shows part of a river food web. Which change would MOST likely reduce the number of both large roach fish and steelhead fish?

• an increase in the amount of algae

• an increase in the number of small invertebrates

• a decrease in the number of predatory invertebrates

• a decrease in the number of young stickleback fish