# Genetic modification can be used to produce crops with beneficial characteristics. Describe the roles of restriction enzymes and DNA ligase in the genetic modification of an organism.

> Cambridge International IGCSE Biology (0610) — 21.3 Genetic modification · Describe · 4 marks

## Mark scheme (4 marks)

1. Restriction enzymes cut DNA at specific sequences to isolate the desired gene
2. Restriction enzymes produce sticky ends on the isolated gene (and on the cut plasmid)
3. The same restriction enzymes are used to cut the plasmid, producing complementary sticky ends
4. DNA ligase joins / seals the complementary sticky ends of the gene and plasmid together to form recombinant DNA / a recombinant plasmid

## Key terms

- [restriction enzymes](https://www.gradenine.co.uk/glossary/restriction-enzymes)
- [DNA ligase](https://www.gradenine.co.uk/glossary/dna-ligase)

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Source: [GradeNine](https://www.gradenine.co.uk/q/genetic-modification-can-be-used-to-965db26c) · Published by Druglandscape Ltd.