# Explain why bacteria and viruses are both described as pathogens, and state ONE difference between the way bacteria and viruses cause disease.

> WJEC GCSE Biology (Wales) — 2.6.1 Pathogens and disease · Explain · 4 marks

## Mark scheme (4 marks)

1. A pathogen is a microorganism that causes disease / infection
2. Both bacteria and viruses can invade / enter the body and cause disease / illness
3. Bacteria produce toxins / release harmful chemicals that damage tissues / cause symptoms
4. Viruses reproduce / replicate inside host cells, causing cell damage / destruction

## Key terms

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

## Related

- [Revision notes for WJEC GCSE Biology (Wales)](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/explain-why-bacteria-and-viruses-are-69a5350d) · Published by Druglandscape Ltd.