# Cholera is a communicable disease caused by the bacterium Vibrio cholerae. Explain how cholera spreads between individuals and describe TWO ways in which the body defends itself against pathogens such as Vibrio cholerae.

> Edexcel A-Level Biology A: Salters-Nuffield (9BN0) — 5.2 Pathogens and infection · Explain · 5 marks

> Cholera causes severe diarrhoea and dehydration. Outbreaks are common in areas where clean drinking water is not available.

## Mark scheme (5 marks)

1. Cholera is a water-borne disease, spread through contaminated water (or food)
2. The bacterium enters the body when contaminated water or food is consumed / ingested
3. First named physical / chemical barrier defence — e.g. hydrochloric acid in the stomach kills bacteria / mucus traps pathogens / cilia waft pathogens away from the lungs
4. B-lymphocytes produce antibodies specific to the antigen on Vibrio cholerae
5. Antibodies trigger an immune response that destroys / neutralises the pathogen (or leads to its destruction)

## Key terms

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

## Related

- [Revision notes for Edexcel A-Level Biology A: Salters-Nuffield (9BN0)](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/cholera-is-a-communicable-disease-caused-d07d10d8) · Published by Druglandscape Ltd.