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Worksheet4th GradeLevel 2 · Standard

Free 4th Grade Decomposers: Nature's Recyclers Worksheet

Students learn how decomposers such as fungi, bacteria and earthworms break down dead plants and animals, how this returns nutrients to the soil for new plants, what conditions help decay happen faster, and how a compost bin uses decomposers.

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Grade
4th Grade
Subject
Science
Topic
Ecosystems & Food Chains
Difficulty
Level 2 · Standard
Estimated time
30 minutes
Curriculum
Texas grade levels (TEKS)
Questions
16
Answers
Included, with working
Format
PDF (A4), print or complete online

Students will practice

  • describing the role of decomposers
  • explaining how nutrients are recycled
  • identifying conditions that affect decay
  • interpreting a decay investigation

Curriculum: Texas grade levels (TEKS). We show specific outcome codes only where they have been verified against the official curriculum document.

What's next?

Completed: Decomposers: Nature's Recyclers

Ready for more? Move on to 5th Grade Science.

How to use this worksheet

  1. Print the PDF or complete it on screen. Write the student's name and date at the top.
  2. Read the instructions for each part together before starting. Encourage working to be shown.
  3. Mark with the answer sheet. Use the model answers and success criteria as a guide rather than a single right answer.
  4. Record the score, celebrate what went well, then follow the "What's next" suggestion.

Common questions

Who is this worksheet for?

4th Grade students (typically ages 9–10) working on ecosystems & food chains. It is pitched at level 2 · standard.

Are the answers included?

Yes. The PDF includes a full answer sheet with model answers and success criteria where there is more than one good answer. You can also view the answers online.

How long does it take?

About 30 minutes for 16 questions. Short, regular sessions work best: two or three a week beats one long one.

Do I need to sign up to download?

No. Click Download Free PDF and it opens immediately. It is free for personal, classroom and homeschool use.

What should we do next?

Explore more 4th Grade science resources.

Preview

Success TutoringWorksheets4th Grade · Science · Ecosystems & Food Chains

Decomposers: Nature's Recyclers

Name

Date

Score /

Use the words decomposer, decay, nutrients and recycle.

Part A: The clean-up crew

Read the passage. Then circle the best answer.

When plants and animals die, they do not stay around for ever. They are broken down by decomposers. Breaking down is called decay or decomposition.

The main decomposers are fungi (such as mushrooms and mold) and bacteria (living things too small to see). Animals such as earthworms, beetles and millipedes help by eating dead material and breaking it into smaller pieces.

As decomposers feed, they release nutrients from the dead material back into the soil. Plants take in these nutrients through their roots and use them to grow. Then animals eat the plants. This is how nutrients are recycled in an ecosystem.

Decomposers work fastest when it is warm and damp and there is some air. Cold, dry conditions slow decay down — that is one reason we keep food in the fridge.

1.What do decomposers do?
  1. Amake food from sunlight
  2. Bbreak down dead plants and animals
  3. Chunt live animals
  4. Dmake rain
2.Which of these is a decomposer?
  1. Aa mushroom
  2. Ba hawk
  3. Ca rabbit
  4. Da sunflower
3.Why are decomposers important for plants?
  1. AThey eat the plants' leaves.
  2. BThey return nutrients to the soil.
  3. CThey block the sunlight.
  4. DThey make the soil dry.
4.Which conditions help an apple core decay fastest?
  1. Acold and dry
  2. Bwarm and damp
  3. Cfrozen
  4. Dsealed in a dry jar
5.What would happen if there were no decomposers?
  1. ADead things would pile up and soil would run out of nutrients.
  2. BPlants would grow faster.
  3. CThere would be more rain.
  4. DNothing would change.

Part B: Recycling nutrients

6.Match each word to its meaning.
  • decomposer
  • nutrients
  • decay
  • substances plants need to grow
  • the breaking down of dead things
  • a living thing that breaks down dead material
7.Mushrooms and mold belong to a group of living things called (answer space).
8.Decomposers work best when it is warm and (answer space).
9.Explain how a fallen leaf can help a new plant grow. (answer space)

Part C: True or false?

Write True or False.

10.Bacteria are too small to see without a microscope. ☐ True   ☐ False
11.Decomposers are harmful and an ecosystem would be better without them. ☐ True   ☐ False
12.Food decays more slowly in the fridge. ☐ True   ☐ False
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Preview — the PDF contains the full resource and answer sheet.

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About this resource

Created by
Success Tutoring Science Team
Last reviewed
1 October 2026
How it was made
Written by our team

Free to print and share for personal, classroom and homeschool use. Please don't resell. Spotted an error? Let us know.