# Explain why a diploid nucleus is used, rather than a nucleus from a gamete, when cloning a mammal by somatic cell nuclear transfer.

> Pearson Edexcel International GCSE Biology (4BI1) — 5.4 Cloning · Explain · 4 marks

> Scientists cloned a sheep named Dolly by removing the nucleus from an unfertilised egg cell and replacing it with a nucleus taken from an udder cell of an adult sheep. The resulting clone was genetically identical to the adult sheep that donated the nucleus.

## Mark scheme (4 marks)

1. A diploid nucleus contains two sets of chromosomes
2. This ensures the clone has the full / correct number of chromosomes (in every body cell)
3. A gamete nucleus is haploid and contains only one set of chromosomes
4. Using a haploid nucleus would not produce an organism genetically identical to the donor / the clone would not develop correctly

## Key terms

- [diploid nucleus](https://www.gradenine.co.uk/glossary/diploid-nucleus)
- [cloning](https://www.gradenine.co.uk/glossary/cloning)

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](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-a-diploid-nucleus-is-69a943b4) · Published by Druglandscape Ltd.