# Explain why energy is lost as it passes along a food chain, and state one consequence of this energy loss for the number of trophic levels in a food chain.

> Cambridge International IGCSE Biology (0610) — 19.2 Food chains and food webs · Explain · 4 marks

## Mark scheme (4 marks)

1. Energy is lost because not all material can be digested (e.g. fur, bones, cellulose)
2. Energy is lost through respiration / used for movement / maintaining body temperature
3. Energy is lost through excretion / decay
4. Because energy is lost at each trophic level, there is usually a maximum of five trophic levels / food chains are rarely longer than five trophic levels, as there would be insufficient energy to support further levels

## Key terms

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

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](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-energy-is-lost-as-37f932f9) · Published by Druglandscape Ltd.