5th grade ecosystems and food chains

Question 1

Decomposers: which statement is NOT true?

• A. Fungi and bacteria are decomposers.
• B. Decomposition is faster when it is warm and moist.
• C. Decomposers return nutrients to the soil.
• D. Decomposers work fastest when frozen.

Question 2

Wolves were brought back to Yellowstone National Park. Deer stopped overeating young trees along rivers. What does this show?

• A. Wolves eat trees.
• B. Trees grow only near wolves.
• C. Deer and wolves never interact.
• D. A change to one predator can affect plants and the whole ecosystem.

Question 3

True or false? Changing one population never affects others in the web.

• A. True
• B. False

Question 4

What do decomposers do?

• A. break down dead plants and animals
• B. make food from sunlight
• C. pollinate flowers
• D. hunt living animals

Question 5

Here is an ocean food web. (An arrow points from the food to the animal that eats it.) phytoplankton → zooplankton kelp (seaweed) → sea urchin zooplankton → herring sea urchin → sea otter herring → seal seal → orca herring → orca Which of these is a producer?

• A. herring
• B. sea urchin
• C. seal
• D. phytoplankton

Question 6

Here is a woodland food web. (An arrow points from the food to the animal that eats it.) oak tree → caterpillar grass → rabbit oak tree → mouse grass → mouse caterpillar → blue tit rabbit → fox mouse → fox mouse → owl blue tit → owl Which of these does the blue tit eat?

• A. caterpillar
• B. rabbit
• C. fox
• D. mouse

Question 7

Is a caterpillar a producer, a consumer or a decomposer?

• A. producer
• B. consumer
• C. decomposer

Question 8

True or false? All the energy in grass passes to the cow that eats it.

• A. True
• B. False

Question 9

Here is an ocean food web. (An arrow points from the food to the animal that eats it.) phytoplankton → zooplankton kelp (seaweed) → sea urchin zooplankton → herring sea urchin → sea otter herring → seal seal → orca herring → orca A disease kills most of the seal. Which animal loses one of its foods?

• A. orca
• B. sea otter
• C. herring
• D. sea urchin

Question 10

How do plants store energy from sunlight?

• A. They do not store energy.
• B. They keep sunlight in their roots.
• C. They turn sunlight into soil.
• D. They use it to make sugars from carbon dioxide and water.

Question 11

What is a likely knock-on effect: a pesticide kills most of the insects in a field?

• A. insect-eating birds have less food
• B. reef fish lose food and shelter
• C. birds that eat small fish have less food
• D. rabbit numbers rise and more grass is eaten

Question 12

Decomposers: which statement is NOT true?

• A. Decomposition is faster when it is warm and moist.
• B. Fungi and bacteria are decomposers.
• C. Fungi are plants.
• D. Matter is recycled in an ecosystem.

Question 13

In a meadow, rabbits are eaten by foxes. A disease kills many rabbits. What will probably happen to the foxes?

• A. Their numbers will rise quickly.
• B. They will grow bigger.
• C. They will start eating grass.
• D. They will struggle to find food and their numbers may fall.

Question 14

True or false? Food webs only include animals.

• A. True
• B. False

Question 15

Compost heaps rot faster when they are…

• A. warm, moist and have air
• B. sealed in plastic with no air
• C. completely dry
• D. frozen