# A scientist wants to produce a crop plant that is resistant to a particular herbicide. The scientist plans to use genetic engineering to insert a gene from a bacterium into the crop plant's genome. Explain how genetic engineering could be used to produce herbicide-resistant crop plants, and describe one potential benefit and one potential risk of releasing these genetically modified plants into the environment.

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

> Genetic engineering allows scientists to transfer genes from one organism to another, creating organisms with new characteristics. Herbicide-resistant crop plants have been developed to allow farmers to spray fields with herbicides without harming the crop.

## Mark scheme (5 marks)

1. The gene for herbicide resistance is identified and cut from the bacterium's DNA
2. The gene is inserted into the crop plant's genome / DNA
3. The modified plant can now express the gene and produce the protein that confers herbicide resistance / the plant's phenotype is changed
4. One benefit: increased crop yield / farmers can spray herbicides to kill weeds without damaging the crop, resulting in more food production
5. One risk: the herbicide-resistance gene could spread to wild plant species / weeds via cross-pollination, creating 'superweeds' that are difficult to control

## Key terms

- [genetic engineering](https://www.gradenine.co.uk/glossary/genetic-engineering)
- [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/a-scientist-wants-to-produce-a-9d43e3a3) · Published by Druglandscape Ltd.