# Describe the role of valves in the heart, and explain why the wall of the left ventricle is thicker than the wall of the right ventricle.

> Cambridge International IGCSE Biology (0610) — 9.2 Heart · Describe and Explain · 4 marks

## Mark scheme (4 marks)

1. Valves prevent the backflow of blood (in the heart).
2. Named example of a valve and its correct location between two named chambers or between a ventricle and an artery.
3. The left ventricle must pump blood at higher pressure / over a greater distance than the right ventricle.
4. A thicker muscular wall allows the left ventricle to contract more forcefully / generate greater pressure.

## Key terms

- [valves](https://www.gradenine.co.uk/glossary/valves)
- [left ventricle](https://www.gradenine.co.uk/glossary/left-ventricle)
- [right ventricle](https://www.gradenine.co.uk/glossary/right-ventricle)

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and 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/describe-the-role-of-valves-in-73fc074a) · Published by Druglandscape Ltd.