# HIV is a communicable disease that can lead to AIDS. Explain how HIV affects the immune system and why people with AIDS are more likely to die from other infections.

> WJEC A-Level Biology (Wales) — 3.5 Human impact on the environment · Explain · 5 marks

> HIV is transmitted through bodily fluids and destroys white blood cells. Over time, this leads to AIDS, in which the immune system is severely weakened.

## Mark scheme (5 marks)

1. HIV destroys / attacks white blood cells
2. Fewer lymphocytes / phagocytes available to produce antibodies or carry out phagocytosis
3. The immune system is weakened / cannot respond effectively to pathogens
4. Pathogens that enter the body cannot be neutralised / destroyed as quickly or effectively
5. Other infections / diseases can therefore take hold and become fatal because the immune system cannot mount an adequate specific defence

## Key terms

- [HIV](https://www.gradenine.co.uk/glossary/hiv)
- [AIDS](https://www.gradenine.co.uk/glossary/aids)
- [immune system](https://www.gradenine.co.uk/glossary/immune-system)

## 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/hiv-is-a-communicable-disease-that-6f9d50dc) · Published by Druglandscape Ltd.