# Influenza is a communicable disease caused by a virus. Explain how the human body responds to an influenza infection, from the point at which the virus enters the body to the destruction of the pathogen.

> Eduqas A-Level Biology — 3.5 Human impact on the environment · Explain · 5 marks

## Mark scheme (5 marks)

1. Non-specific defence / barrier is the first line of defence (e.g. skin, mucus, hairs in the nose, stomach acid)
2. White blood cells detect the virus using antigens on its surface
3. Lymphocytes produce antibodies that are specific / complementary to the antigens on the influenza virus
4. Antibodies bind to antigens on the virus to neutralise / clump (agglutinate) the pathogens together
5. Phagocytes engulf and digest the pathogen (phagocytosis) / memory cells remain so future infection is destroyed more quickly

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level Biology](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/influenza-is-a-communicable-disease-caused-6f2e6d38) · Published by Druglandscape Ltd.