# Explain why only a small percentage of the energy available at one trophic level is transferred to the next trophic level in a food chain.

> AQA A-Level Biology (7402) — 3.5.3 Energy and Ecosystems · Explain · 5 marks

## Mark scheme (5 marks)

1. Energy is lost through movement / respiration by organisms at each trophic level
2. Energy is lost as heat (to the surroundings / environment)
3. Not all of the organism is eaten / some biomass is not consumed
4. Energy is lost in faeces / undigested material that passes out of the body
5. Only the energy stored in the biomass of organisms at one trophic level is available to the next trophic level

## Key terms

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

## Related

- [Revision notes for AQA A-Level Biology (7402)](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-only-a-small-percentage-585c2e4f) · Published by Druglandscape Ltd.