# Explain why homeostasis is important for the body and describe two processes that the kidneys carry out as part of homeostasis.

> Eduqas A-Level Biology — 3.7 Homeostasis and the kidney · Explain · 5 marks

> Homeostasis is the maintenance of a constant internal environment. The kidneys play a central role in homeostasis in humans.

## Mark scheme (5 marks)

1. Homeostasis keeps internal conditions within narrow/constant limits (accept: keeps conditions stable/balanced)
2. So that cells/enzymes function correctly / optimally (accept: so metabolic reactions can occur at the correct rate)
3. The kidneys filter the blood / remove waste products (e.g. urea) from the blood
4. The kidneys regulate/control the water content of the blood (osmoregulation)
5. The kidneys regulate ion/salt concentration of the blood (accept: control levels of ions such as sodium in the blood)

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level Biology](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-homeostasis-is-important-for-eccd339e) · Published by Druglandscape Ltd.