5th grade ecosystems and food chains

Question 1

Why are there usually far fewer foxes than rabbits in a field?

• A. Foxes do not like each other.
• B. Rabbits eat foxes.
• C. Much energy is used up or lost at each step of a food chain.
• D. Foxes do not need energy.

Question 2

True or false? Animals get energy directly from sunlight like plants.

• A. True
• B. False

Question 3

True or false? Removing a predator can cause its prey to increase.

• A. True
• B. False

Question 4

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. seal
• B. kelp (seaweed)
• C. zooplankton
• D. orca

Question 5

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

Question 6

Why are decomposers important for plants?

• A. They release nutrients (minerals) back into the soil
• B. They make plants grow faster in the dark
• C. They give plants sunlight
• D. They eat plant pests only

Question 7

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 sea urchin. Which animal loses one of its foods?

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

Question 8

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 does the herring eat?

• A. zooplankton
• B. orca
• C. phytoplankton
• D. kelp (seaweed)

Question 9

Is a bracket fungus on a dead log a producer, a consumer or a decomposer?

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

Question 10

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 11

Decomposers: which statement is NOT true?

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

Question 12

Why do the arrows in a food chain point from the food to the eater?

• A. They show the direction energy flows.
• B. They show who is bigger.
• C. They show who is faster.
• D. They point to the oldest animal.

Question 13

True or false? Plants are producers because they make food using light.

• A. True
• B. False

Question 14

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

• A. True
• B. False

Question 15

Here is a pond food web. (An arrow points from the food to the animal that eats it.) algae → mayfly larva algae → tadpole pondweed → pond snail algae → pond snail mayfly larva → dragonfly larva tadpole → dragonfly larva mayfly larva → stickleback (small fish) dragonfly larva → stickleback (small fish) stickleback (small fish) → heron tadpole → heron Which of these is a producer?

• A. stickleback (small fish)
• B. heron
• C. pondweed
• D. tadpole