Ecosystems

Which comparison of ecosystems is true?

• Tundras are warmer than grasslands.

• Grasslands get more rain than deserts.

• Deserts have more plants than rainforests.

• Rainforests are rockier than tundras.

Which two organisms in the food chain shown above are carnivorous?

• grass and mice

• mice and snakes

• hawks and grass

• snakes and hawks

The Russian thistle, commonly known as the tumbleweed, is a big, round plant with many branches and short, stiff leaves. This plant spreads a large number of seeds when it breaks off from its stalk. The thistle is most likely found in what kind of environment?

• swamp

• prairie

• forest

• tundra

A brown bear eats a variety of foods including berries, insects, and small animals. Which best describes a brown bear?

• producer

• herbivore

• carnivore

• omnivore

Which is an example of a decomposer?

• a hawk

• a mouse

• a flower

• a mushroom

In which ecosystem can the greatest variety of organisms be found?

• lake

• estuary

• rainforest

• stream

Which best describes a characteristic of both lakes and estuaries?

• Both have saltwater.

• Both have freshwater.

• Both have a rocky bottom.

In the food web, which organisms are producers?

• frog and rat

• rat and leaves

• leaves and berries

Which ecosystem would most likely contain fish that can only survive in freshwater?

• lake

• ocean

• estuary

Which best explains why the sun is important to all ecosystems?

• It provides heat.

• It provides daylight.

• Producers rely on it to make their food.