Explain how scientists could use genetic engineering to produce human insulin in bacteria.

Eduqas GCSE Biology — 7.4 Selective breeding and gene technology · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

People with type 1 diabetes need insulin. Scientists can use genetic engineering to insert the human insulin gene into bacteria, which then produce insulin that can be harvested for medical use.

Model answer (4 marks)

1. The human insulin gene is isolated from human DNA.
2. The gene is inserted into a bacterial plasmid (vector).
3. The plasmid is introduced into the bacterium (transformation).
4. The bacteria replicate and produce human insulin.

Examiner tips

Use the exact sequence of steps: isolation, insertion, transformation, production.
Show the role of the plasmid as a vector and that bacteria multiply to produce insulin.

Common mistakes

Confusing isolation with cutting the gene; not mentioning the plasmid as a vector; omitting that bacteria replicate to produce insulin.

Mark scheme (4 marks)

The human insulin gene is cut/removed from human DNA
The gene is inserted into a vector / bacterial plasmid
The plasmid / vector is introduced into the bacterium
The bacteria multiply / reproduce and produce human insulin

Key terms in this question

genetic engineering