# Describe how the use of insecticides, herbicides, chemical fertilisers and selective breeding each contribute to increasing crop yield in modern farming.

> Cambridge International IGCSE Biology (0610) — 20.1 Food supply · Describe · 4 marks

## Mark scheme (4 marks)

1. Insecticides kill insects that damage or consume crops, reducing crop losses
2. Herbicides kill weeds, reducing competition with crops for nutrients, water or light
3. Chemical fertilisers increase the amount of nutrients / mineral salts in the soil, so plants grow larger and produce more fruit
4. Selective breeding involves choosing and breeding organisms with desirable characteristics (e.g. high yield) so that offspring also have high yield

## Key terms

- [insecticides](https://www.gradenine.co.uk/glossary/insecticides)
- [herbicides](https://www.gradenine.co.uk/glossary/herbicides)
- [chemical fertilisers](https://www.gradenine.co.uk/glossary/chemical-fertilisers)
- [selective breeding](https://www.gradenine.co.uk/glossary/selective-breeding)
- [yield](https://www.gradenine.co.uk/glossary/yield)

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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/describe-how-the-use-of-insecticides-f5b7395f) · Published by Druglandscape Ltd.