# A farmer decides to rear cattle for beef rather than growing wheat to sell directly as food for humans. Explain why feeding the wheat to cattle before humans eat the beef is a less efficient use of biomass than humans eating the wheat directly.

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

## Mark scheme (4 marks)

1. Biomass is lost at each trophic level / when moving up the food chain
2. Biomass is used by the cattle for respiration / movement / keeping warm
3. Adding an extra trophic level (cattle) means more biomass is lost overall before it reaches humans
4. If humans eat wheat directly (as producers / at a lower trophic level) more biomass is available to them

## Key terms

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

## Related

- [Revision notes for AQA GCSE Biology (8461)](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/a-farmer-decides-to-rear-cattle-4e4c6678) · Published by Druglandscape Ltd.