# Explain why the left ventricle of the heart has a thicker wall than the right ventricle, and describe the role of the atrioventricular valves in ensuring blood flows in the correct direction.

> WJEC A-Level Biology (Wales) — 2.1 Classification and biodiversity · Explain · 5 marks

## Mark scheme (5 marks)

1. The left ventricle pumps blood around the entire/whole body (systemic circulation)
2. The left ventricle must generate a higher/greater blood pressure than the right ventricle
3. A thicker wall means a more powerful contraction (to generate this high pressure)
4. The atrioventricular valves are located between the atria and the ventricles
5. The atrioventricular valves prevent backflow of blood from the ventricles into the atria

## Key terms

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

## 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-why-the-left-ventricle-of-ead70ec6) · Published by Druglandscape Ltd.