# Explain why only around 10% of the energy available at one trophic level is transferred to the next trophic level in a food chain.

> Pearson Edexcel International GCSE Biology (4BI1) — 4.2 Feeding relationships · Explain · 4 marks

> In a grassland ecosystem, grass is eaten by rabbits, which are in turn eaten by foxes. At each stage of this food chain, a large proportion of the energy is lost and is not available to the next consumer.

## Mark scheme (4 marks)

1. Energy is lost through respiration / used for metabolic processes / heat loss to the environment
2. Energy is lost in excretion / waste products such as urine or faeces
3. Energy is used for movement / locomotion / physical activity
4. Therefore only the energy stored in the biomass of the organism is available to the next trophic level

## Key terms

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

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](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-around-10-of-95f11ea4) · Published by Druglandscape Ltd.