# Scientists have used genetic engineering to produce insulin in bacteria. Explain how a human insulin gene is inserted into a bacterium to produce large quantities of insulin.

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

> People with Type 1 diabetes need regular doses of insulin. Before genetic engineering, insulin was extracted from the pancreases of pigs and cows. Today, genetically engineered bacteria are used to manufacture human insulin on a large scale.

## Mark scheme (5 marks)

1. The human insulin gene is identified/located on a human chromosome
2. The gene is cut out using enzymes
3. A plasmid (from a bacterium) is cut open using enzymes
4. The insulin gene is inserted into the plasmid and sealed/joined using enzymes
5. The plasmid is inserted into a bacterium, which then replicates/reproduces to produce large quantities of insulin

## Key terms

- [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)
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Source: [GradeNine](https://www.gradenine.co.uk/q/scientists-have-used-genetic-engineering-to-09e54b56) · Published by Druglandscape Ltd.