# Explain why DNA is described as a polymer made up of monomers, and state what the monomers of DNA are called.

> WJEC GCSE Biology (Wales) — 2.3.1 DNA structure · Explain · 4 marks

> DNA carries the genetic information needed to build and run every living organism. Scientists classify DNA as a biological polymer.

## Mark scheme (4 marks)

1. A polymer is a large molecule made up of many repeated smaller units (monomers) joined together
2. DNA is a polymer because it is made of many monomers joined in a long chain
3. The monomers of DNA are called nucleotides
4. Each nucleotide contains a sugar (deoxyribose), a phosphate group, and one of four bases

## Key terms

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

## 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)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-dna-is-described-as-d330c158) · Published by Druglandscape Ltd.