# Explain how the kidneys help to maintain homeostasis in the body.

> WJEC A-Level Biology (Wales) — 3.7 Homeostasis and the kidney · Explain · 5 marks

> The kidneys play a vital role in keeping the internal environment of the body constant. They filter the blood and produce urine, adjusting its composition depending on the body's needs.

## Mark scheme (5 marks)

1. Homeostasis is the maintenance of a constant internal environment
2. The kidneys filter the blood / remove waste products from the blood
3. Urea is removed / excreted by the kidneys
4. The kidneys regulate/control water content of the blood / body
5. The kidneys regulate ion / salt concentration in the blood

## Key terms

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

## Related

- [Revision notes for WJEC A-Level 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-kidneys-help-to-1bb3c7c7) · Published by Druglandscape Ltd.