# Malaria is a communicable disease caused by the protist Plasmodium, which is spread to humans through the bite of infected female Anopheles mosquitoes. Explain how the spread of malaria can be reduced, and describe the non-specific defences the human body uses if Plasmodium enters the bloodstream.

> Pearson Edexcel A-Level Biology A (9BI0) — 5.2 Pathogens and infection · Explain · 5 marks

> Malaria kills over 600,000 people worldwide each year, predominantly in tropical regions where the Anopheles mosquito is found. Unlike bacterial or viral diseases, malaria is caused by a protist pathogen transmitted by an animal vector.

## Mark scheme (5 marks)

1. Controlling the mosquito vector reduces spread — e.g. draining standing water / using insecticides / mosquito nets to prevent bites
2. The skin acts as a physical barrier preventing Plasmodium from entering the body
3. If Plasmodium enters the blood, white blood cells (phagocytes) engulf and destroy the pathogen by phagocytosis
4. B-lymphocytes detect the antigens on the surface of Plasmodium and produce specific antibodies
5. Antibodies bind to the antigens on Plasmodium, neutralising or marking it for destruction / triggering an immune response

## Key terms

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

## Related

- [Revision notes for Pearson Edexcel A-Level Biology A (9BI0)](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/malaria-is-a-communicable-disease-caused-455db3df) · Published by Druglandscape Ltd.