# Explain why decomposers are essential for returning nutrients to the soil, and describe what would happen to plant growth if decomposers were absent from an ecosystem.

> WJEC GCSE Biology (Wales) — 1.6.2 Nutrient cycles · Explain · 4 marks

## Mark scheme (4 marks)

1. Decomposers break down / digest dead organisms (and waste materials)
2. This releases minerals / nutrients (e.g. nitrates / phosphates) back into the soil
3. Without decomposers, dead organic matter / minerals would not be recycled / returned to the soil
4. Plants would not be able to absorb sufficient minerals / nitrates, so growth would be reduced / stunted

## Key terms

- [decomposers](https://www.gradenine.co.uk/glossary/decomposers)
- [nutrients](https://www.gradenine.co.uk/glossary/nutrients)

## Related

- [Revision notes for WJEC GCSE Biology (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-decomposers-are-essential-for-104e2fd4) · Published by Druglandscape Ltd.