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What genetic modification is

Biotechnology and genetic modification · Genetic modification · note 1 of 3

What genetic modification isSpec 21.3.1, 21.3.2

In short

Genetic modification is changing the genetic material of an organism by removing, changing or inserting individual genes. The result is a genetically modified organism, often with a gene from another species. Examples include bacteria that make human insulin, herbicide-resistant and insect-resistant crops, and golden rice, which contains a vitamin A precursor to improve its nutritional quality.

Genetic modification is changing the genetic material of an organism by removing, changing or inserting individual genes. An organism that has had its genes altered in this way is called a genetically modified organism (GMO). The inserted gene is often taken from another species.

Examples of genetic modification
ExampleWhat is doneResult
Human protein from bacteriaHuman genes are inserted into bacteriaBacteria make human proteins, such as insulin
Herbicide resistanceGenes are inserted into crop plantsThe crop is not killed by a herbicide, so the field can be sprayed to kill weeds without harming the crop
Insect resistanceGenes are inserted into crop plantsCrop is resistant to insect pests, so less insecticide is needed and yield is higher
Improved nutritional qualityGenes are inserted into crop plantsCrop contains more of a nutrient; for example, rice modified to contain a vitamin A precursor (golden rice)
Exam tip:

Use the word 'gene' in the definition: genetic modification changes an organism by removing, changing or inserting individual genes, not 'changing the whole organism'.

Written and checked against the Cambridge IGCSE Biology (0610) specification · Updated October 2026

Frequently asked questions

What is genetic engineering in agriculture?

Genetic engineering in agriculture means genetically modifying crop plants by inserting genes, often from another species. Examples are herbicide-resistant crops, which can be sprayed to kill weeds without being harmed, insect-resistant crops that need less insecticide, and crops with improved nutritional quality, such as golden rice, which contains a vitamin A precursor.

How is human insulin made by bacteria?

Supplement Human insulin is made by inserting the human insulin gene into bacteria. Restriction enzymes cut the gene out of human DNA, leaving sticky ends, and cut open a plasmid with matching sticky ends. DNA ligase joins the gene into the plasmid, making a recombinant plasmid. The bacteria multiply and express the gene, making insulin.

What do restriction enzymes and DNA ligase do?

Supplement Restriction enzymes cut DNA, leaving short single-stranded overhangs called sticky ends, while DNA ligase joins DNA. In genetic modification, the same restriction enzyme cuts out the human gene and cuts open the plasmid, so the sticky ends match. DNA ligase then joins the gene into the plasmid to form a recombinant plasmid.

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