# Explain how a polymer is formed from monomers, and why this process is important in living organisms.

> AQA A-Level Biology (7402) — 3.1.1 Monomers and Polymers · Explain · 5 marks

## Mark scheme (5 marks)

1. Monomers are small/single molecules that are the building blocks of polymers
2. Monomers are joined together by chemical bonds to form a polymer
3. The process of joining monomers to form a polymer is called polymerisation
4. A polymer is a long chain/large molecule made of many repeating monomer units
5. Polymers are important because large biological molecules (such as DNA, proteins, or carbohydrates) are polymers that carry out essential functions in living organisms

## Key terms

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

## Related

- [Revision notes for AQA A-Level Biology (7402)](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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-a-polymer-is-formed-ae417fd5) · Published by Druglandscape Ltd.