Ecosystems Review

What do plants give off into the air that animals need?

• oxygen

• carbon dioxide

• pollen

• sunlight

Which will most likely cause a decrease in predator populations?

• an increase in prey populations

• a decrease in prey populations

• a decrease in decomposers

• an increase in producers

When animals breathe, they give off carbon dioxide. What happens to this gas?

• It becomes part of the soil.

• Plants use it in photosynthesis

• Other animals use it to breathe

• Predators compete for it

Both deer and squirrels needing acorns for food is an example of

• reproducing

• hunting

• competion

• photosynthesis

When does the greatest competition occur for food and water between organisms from different populations?

• when the populations require similar shelter

• when the populations occupy the same niche ( which means all animals live in the same area and eat the same food)

• when the populations are in different ecosystems

• when the populations hunt at the same time of day

Which is a benefit of having different types of producers in an ecosystem?

• There is more competition for food by consumers.

• The ecosystem can support more types of consumers.

• There will be more decomposers living in the ecosystem.

• The ecosystem will be better able to support carnivores.

Which best explains why predators need other animals within an ecosystem?

• They depend on them for food.

• They depend on them for water.

• They depend on them for protection.

• They depend on them for competition

Which best describes an animal that hunts living animals for food?

• herbivore

• predator

• prey

• scavenger

Which consumer in a grassland ecosystem would be considered both predator and prey?

• a grasshopper, because it eats grass and is eaten by birds

• a rabbit, because it eats snakes and is eaten by deer

• a snake, because it eats mice and is eaten by hawks

• an earthworm, because it eats dead animals and is eaten by birds

What would most likely result if all plants in an area were destroyed?

• Consumer populations would increase because more sunlight would reach the ground.

• Decomposer populations would increase because more sunlight would reach the ground

• Consumer populations would decrease because plants provide them with water.

• Consumer populations would decrease because plants provide them with energy.