# DNA is a naturally occurring polymer found in the nucleus of living cells. Explain how the structure of DNA as a polymer relates to its function in storing genetic information, and describe one key difference between DNA as a natural polymer and a synthetic polymer such as polythene.

> OCR A-Level Chemistry B: Salters (H433) — PL Polymers and life · Explain · 5 marks

> DNA (deoxyribonucleic acid) is a polymer made from monomers called nucleotides. The sequence of these monomers along the DNA chain encodes the instructions needed to build and operate a living organism. Polythene is a synthetic polymer made from ethene monomers and is used to make plastic bags and bottles.

## Mark scheme (5 marks)

1. DNA is a polymer made from many monomers (nucleotides) joined together
2. The sequence/order of monomers in DNA stores genetic information
3. A large number of different monomer sequences are possible, allowing a vast amount of information to be stored
4. DNA is a natural polymer (produced by living organisms) whereas polythene is a synthetic polymer (made by humans / in industry)
5. DNA has a variety of different monomer units (four different nucleotides), whereas polythene is made from only one type of monomer (ethene/identical repeat units)

## Key terms

- [polymer](https://www.gradenine.co.uk/glossary/polymer)
- [natural polymer](https://www.gradenine.co.uk/glossary/natural-polymer)
- [synthetic polymer](https://www.gradenine.co.uk/glossary/synthetic-polymer)
- [genetic information](https://www.gradenine.co.uk/glossary/genetic-information)

## Related

- [Revision notes for OCR A-Level Chemistry B: Salters (H433)](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/dna-is-a-naturally-occurring-polymer-8d000ba4) · Published by Druglandscape Ltd.