# Describe how white blood cells defend the body after a pathogen has entered the bloodstream.

> Cambridge International IGCSE Biology (0610) — 10.1 Diseases and immunity · Describe · 4 marks

## Mark scheme (4 marks)

1. Phagocytes engulf and destroy pathogens by phagocytosis
2. Lymphocytes detect specific antigens on the surface of the pathogen
3. Lymphocytes produce specific antibodies complementary to the antigen
4. Antibodies bind to antigens causing pathogens to clump together / be marked for destruction by phagocytes

## Key terms

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

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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-white-blood-cells-defend-e3380d88) · Published by Druglandscape Ltd.