# Explain why some mutations that occur in somatic cells are not inherited by offspring, whereas mutations in germline cells can be passed on to future generations.

> IB DP Biology Higher Level (2023 syllabus) — D1.3 Mutations and gene editing (HL only) · Explain · 4 marks

## Mark scheme (4 marks)

1. Somatic cells are non-reproductive body cells that do not contribute to gamete formation.
2. A mutation in a somatic cell is passed only to daughter cells by mitosis, so remains confined to a clone of cells in that individual.
3. Germline cells (cells that give rise to gametes, e.g. in gonads) carry mutations that are incorporated into eggs or sperm.
4. At fertilisation, a gamete carrying the germline mutation contributes the mutant allele to every cell of the new organism, making the mutation heritable.

## Key terms

- [somatic cell](https://www.gradenine.co.uk/glossary/somatic-cell)
- [germline cell](https://www.gradenine.co.uk/glossary/germline-cell)
- [mutation](https://www.gradenine.co.uk/glossary/mutation)

## Related

- [Revision notes for IB DP Biology Higher Level (2023 syllabus)](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-some-mutations-that-occur-1cd29ba9) · Published by Druglandscape Ltd.