# Describe the roles of the lungs and the skin as organs of excretion in humans.

> Pearson Edexcel International GCSE Biology (4BI1) — 2.13 Excretion: humans · Describe · 4 marks

## Mark scheme (4 marks)

1. The lungs excrete carbon dioxide (produced during respiration)
2. The lungs also excrete water (vapour)
3. The skin excretes sweat / sweat contains water and urea (and salts)
4. Excretion is the removal of waste products of metabolism from the body

## Key terms

- [excretion](https://www.gradenine.co.uk/glossary/excretion)
- [lungs](https://www.gradenine.co.uk/glossary/lungs)
- [skin](https://www.gradenine.co.uk/glossary/skin)

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](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-the-roles-of-the-lungs-2e5db381) · Published by Druglandscape Ltd.