# Describe how bacteria are used in the production of yoghurt from milk.

> WJEC GCSE Biology (Wales) — 2.7 Micro-organisms and their applications · Describe · 4 marks

## Mark scheme (4 marks)

1. Bacteria are added to warm milk
2. Bacteria ferment the lactose (sugar) in the milk
3. Lactic acid is produced during fermentation
4. The lactic acid causes the milk to thicken / curdle / become more acidic, forming yoghurt

## Key terms

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

## Related

- [Revision notes for WJEC GCSE Biology (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-bacteria-are-used-in-f46f559d) · Published by Druglandscape Ltd.