# Explain how the human body uses both non-specific defences and the specific immune response to prevent and destroy a bacterial pathogen that enters the body through a skin wound for the first time.

> WJEC A-Level Biology (Wales) — 3.1 Photosynthesis · Explain · 5 marks

> A person cuts their finger and bacteria enter the body through the broken skin.

## Mark scheme (5 marks)

1. Blood clotting seals the wound, acting as a mechanical barrier to prevent more microorganisms from entering.
2. White blood cells detect antigens on the surface of the bacteria.
3. Phagocytes engulf and digest the bacteria (phagocytosis).
4. Lymphocytes produce specific antibodies that bind to the antigens on the bacteria to neutralise / destroy them.
5. Memory cells remain after the infection so that if the same bacteria enter again, antibodies are produced more quickly.

## Key terms

- [non-specific defence](https://www.gradenine.co.uk/glossary/non-specific-defence)
- [immune response](https://www.gradenine.co.uk/glossary/immune-response)

## 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-how-the-human-body-uses-a7c1036a) · Published by Druglandscape Ltd.