# Describe how trophic levels are organised in a food chain and explain why producers are described as providing biomass for all living things.

> AQA GCSE Biology (8461) — 4.7.4 Trophic levels in an ecosystem (Bio only) · Describe and Explain · 4 marks

## Mark scheme (4 marks)

1. A trophic level is the position of an organism in a food chain
2. Producers are at the first trophic level / start of the food chain
3. Producers are photosynthetic organisms that use light energy to produce organic material / biomass
4. All other organisms (consumers) obtain biomass by eating producers or organisms that have eaten producers, so all biomass in the food chain originates from producers

## Key terms

- [trophic level](https://www.gradenine.co.uk/glossary/trophic-level)
- [producer](https://www.gradenine.co.uk/glossary/producer)
- [biomass](https://www.gradenine.co.uk/glossary/biomass)
- [food chain](https://www.gradenine.co.uk/glossary/food-chain)

## Related

- [Revision notes for AQA GCSE Biology (8461)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and 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/describe-how-trophic-levels-are-organised-b7f7b81f) · Published by Druglandscape Ltd.