4.3.3Use of Biological Resources

GM Plants and Food Production — Edexcel International GCSE Science Double Award (Modular) - Biology Unit 2 Revision Notes & Topical Questions

5 min read 6 parts Lesson 14 of 15

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Part 1 of 4What is a GM crop?

Genetic modification

Genetic modification Genetic modification (genetic engineering) means inserting a gene from another organism into an organism's genome so that it gains a new characteristic.

In crops

In crops The aim is usually to improve food production, for example by giving resistance to pests or herbicides, better nutrition or tolerance of drought.

GM crops

Insect resistance

Insect resistance Maize and wheat given a bacterial gene that makes a toxin harmful to insects such as caterpillars, so less is eaten and yield rises.

Herbicide resistance

Herbicide resistance Crops that survive a herbicide; spraying then kills the weeds but not the crop.

Better nutrition

Better nutrition Golden rice has genes from a plant and a bacterium so that the grains make a chemical the body converts into vitamin A, helping to prevent deficiency disease.

Drought tolerance

Drought tolerance Plants able to grow in very dry conditions, which can raise yield in dry regions.

Advantages	Disadvantages
Less pesticide and herbicide needed, which is better for the environment	GM seed is more expensive, which can put poorer farmers at a disadvantage
Cheaper and less time-consuming for farmers	Farmers may depend on particular herbicides, often sold by the seed company
Higher yields, since there is less competition from weeds and less pest damage	Inserted genes could spread to wild plants by pollination, for example making weeds herbicide-resistant
Added nutrients can improve health	Fewer weeds can reduce biodiversity, affecting insects and the birds that eat them
Drought-tolerant varieties can grow where others fail	Some GM plants may grow less well than non-GM ones, and some people worry that the effects on health are not fully known

State the benefit clearly, such as increased yield or improved nutrition.

Link it to a consequence, such as more food for a growing population or fewer chemicals used.

State a relevant risk, such as gene transfer to weeds, cost or loss of biodiversity.

Finish with a conclusion that weighs the two, noting that continued testing and regulation are needed.

Term	Meaning
Genetic modification	Changing an organism's genome by inserting genes from another organism.
Genome	All the genetic material of an organism.
Herbicide	A chemical that kills plants, used to control weeds.
Golden rice	A GM rice that produces a precursor of vitamin A.
Biodiversity	The variety of living species in an area.

Saying GM crops are made by selective breeding — GM involves directly inserting a gene, often from another species.

Thinking herbicide-resistant crops mean no herbicide is used — herbicide is still sprayed to kill weeds.

Listing only advantages or disadvantages in an evaluation question — give both sides.

Writing that golden rice contains vitamin A — it contains a chemical that the body turns into vitamin A.

Last updated: 20 October 2026