# Explain how the use of pesticides on farmland can lead to a decrease in the population of birds of prey in the area.

> WJEC GCSE Biology (Wales) — 1.6.3 Human impact on the environment · Explain · 4 marks

## Mark scheme (4 marks)

1. Pesticides are sprayed onto crops / used to kill pest insects / invertebrates on farmland
2. The pesticide accumulates / builds up in the body tissues of the insects / small organisms that absorb it (bioaccumulation)
3. Animals that eat large numbers of the contaminated insects / prey (e.g. small birds, mice) accumulate higher concentrations of pesticide in their tissues
4. Birds of prey eat many contaminated prey animals so accumulate toxic / lethal concentrations of pesticide, causing death / reduced reproduction / population decline

## Key terms

- [pesticide](https://www.gradenine.co.uk/glossary/pesticide)
- [birds of prey](https://www.gradenine.co.uk/glossary/birds-of-prey)

## Related

- [Revision notes for WJEC GCSE Biology (Wales)](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-how-the-use-of-pesticides-bf0438ba) · Published by Druglandscape Ltd.