# Describe how the human body uses non-specific defences and the specific immune response to protect itself when a pathogen enters through a cut in the skin.

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

## Mark scheme (5 marks)

1. Non-specific mechanical barrier: blood clotting seals the wound to prevent pathogens entering
2. Phagocytes engulf / ingest pathogens and digest them using enzymes (phagocytosis)
3. Lymphocytes detect antigens on the pathogen surface and release complementary antibodies
4. Antibodies bind to antigens on the pathogen, neutralising it / causing agglutination so the pathogen is destroyed
5. Memory cells remain after infection so that if the same pathogen enters the body again, the response is faster / pathogen is killed more quickly

## Key terms

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

## Related

- [Revision notes for WJEC A-Level Biology (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-the-human-body-uses-6403b722) · Published by Druglandscape Ltd.