# Explain why the heart is described as having two separate sides, and outline why this arrangement is important for supplying oxygen to the body's tissues.

> WJEC GCSE Biology (Wales) — 1.4.1 Blood and circulation · Explain · 4 marks

## Mark scheme (4 marks)

1. The right side of the heart pumps deoxygenated blood to the lungs
2. The left side of the heart pumps oxygenated blood to the rest of the body
3. Keeping oxygenated and deoxygenated blood separate prevents mixing
4. This ensures tissues receive blood with a high oxygen concentration / efficient delivery of oxygen to tissues

## Key terms

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

## Related

- [Revision notes for WJEC GCSE 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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-the-heart-is-described-21207a92) · Published by Druglandscape Ltd.