# Scientists have used genetic engineering to insert a gene into salmon that causes them to grow much faster than normal. Explain the process used to insert the growth gene into the salmon's genome.

> OCR A-Level Biology B — Advancing Biology (H422) — 5.3 Manipulating genomes · Explain · 5 marks

> Farmers who raise salmon for food are interested in using genetically engineered salmon because the fish reach market size in half the usual time. The growth gene originally came from a different species of fish.

## Mark scheme (5 marks)

1. The desired growth gene is identified / located in the donor organism's DNA
2. Restriction enzymes are used to cut out the growth gene from the donor DNA
3. A vector (such as a plasmid or virus) is used to carry / transfer the gene
4. Ligase enzyme is used to join / seal the growth gene into the vector
5. The vector transfers the gene into the salmon's cells so it becomes part of the salmon's genome and is expressed

## Key terms

- [genome](https://www.gradenine.co.uk/glossary/genome)
- [gene](https://www.gradenine.co.uk/glossary/gene)

## Related

- [Revision notes for OCR A-Level Biology B — Advancing Biology (H422)](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/scientists-have-used-genetic-engineering-to-80f9690a) · Published by Druglandscape Ltd.