Ecosystems — Grade 4 Science Practice Worksheet

Grade 4 Easy difficulty 10 problems

An ecosystem is a community of living organisms interacting with each other and their nonliving environment — sunlight, water, soil, and air.

Producers (plants and algae) make their own food through photosynthesis. Consumers eat other organisms. Decomposers break down dead matter and return nutrients to the soil.

Food chains show energy flow from one organism to the next. Food webs show overlapping chains in a community. Energy decreases at each level — only about 10% transfers to the next trophic level.

Skills practiced

  • Identifying producers, consumers, and decomposers
  • Building and reading food chains
  • Understanding energy flow
  • Describing habitat roles
Name: Date: Period:

Practice Worksheet: Ecosystems

Instructions: Solve each problem carefully. Show all work clearly. Write your final answer in the space provided or on a separate sheet as directed.

  1. 1.What is an ecosystem?
  2. 2.Which of the following is a living part of an ecosystem?
    1. A. Sunlight
    2. B. Water
    3. C. Tree
    4. D. Soil
  3. 3.Name two nonliving things in an ecosystem.
  4. 4.A is an animal that eats only plants.
  5. 5.Draw a simple food chain with three parts. Label each part.
  6. 6.Which of the following is a producer in an ecosystem?
    1. A. Fox
    2. B. Grass
    3. C. Mushroom
    4. D. Hawk
  7. 7.What happens to the plants and animals in an ecosystem when there is not enough water?
  8. 8.A is a living thing that breaks down dead plants and animals.
  9. 9.Circle the correct answer: A deer is a (herbivore / carnivore / omnivore).
  10. 10.Why are decomposers important in an ecosystem?

Answer Key

  1. 1.
    Final answer: An ecosystem is a community of living things interacting with each other and with their nonliving environment.
  2. 2.
    Final answer: c) Tree
  3. 3.
    Final answer: Accept any two: sunlight, water, soil, air, rocks, temperature.
  4. 4.
    Final answer: herbivore
  5. 5.
    Final answer: Example: Sun →\rightarrow Grass →\rightarrow Rabbit. (Accept any correct three-part chain with labels.)
  6. 6.
    Final answer: b) Grass
  7. 7.
    Final answer: Plants may wilt or die, and animals may move away or die from lack of water.
  8. 8.
    Final answer: decomposer
  9. 9.
    Final answer: herbivore
  10. 10.
    Final answer: Decomposers break down dead plants and animals, returning nutrients to the soil so new plants can grow.
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Common mistakes to avoid

  • Calling all animals producers
  • Reversing arrow direction in food chains (arrows point to who gets eaten)
  • Forgetting decomposers in food webs
  • Confusing habitat with ecosystem

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