Genetic Modification Pros & Cons IGCSE Biology

Genetic Modification: Evaluating the Benefits and Risks

Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.

Key concept

Genetic modification (GM) offers benefits such as pest-resistant crops, higher yields and production of medical proteins, but raises concerns including ecological risks, reduced biodiversity, ethical issues and unknown long-term effects on health and the environment.

GM evaluation questions are common extended-response questions. Students must present both sides with specific, named examples and avoid vague statements. The strongest answers link each benefit and risk to a biological mechanism or real-world example.

Benefits of genetic modification

Agriculture: GM crops can be engineered for pest resistance (e.g. Bt cotton produces a toxin that kills insect pests, reducing the need for chemical pesticides), herbicide tolerance (allowing farmers to spray weeds without damaging the crop), drought tolerance (allowing crops to grow in dry conditions) and improved nutritional content (e.g. Golden Rice contains beta-carotene to combat vitamin A deficiency).

Medicine: Genetically modified bacteria produce human proteins such as insulin and growth hormone. GM organisms can be used to study diseases and develop new treatments. Gene therapy aims to treat genetic diseases by replacing faulty genes.

Industry: GM microorganisms produce industrial enzymes, biofuels and biodegradable plastics more efficiently.

Risks and concerns

Ecological risks: GM organisms might spread their modified genes to wild populations through cross-pollination. For example, herbicide-resistant genes could transfer to wild plants, creating "superweeds" that are difficult to control. Pest-resistant crops might also harm non-target organisms such as beneficial insects.

Biodiversity: If farmers switch to a few GM varieties, genetic diversity in crop species decreases. A genetically uniform crop is vulnerable to new diseases or pests.

Health concerns: Although no health risks from eating approved GM foods have been demonstrated, some people worry about unknown long-term effects. Allergies could potentially be introduced if proteins from allergenic organisms are transferred.

Ethical and social considerations

Ethical concerns: Some people believe modifying organisms is morally wrong and interferes with nature. Others argue that traditional selective breeding also modifies organisms, just more slowly. Animal welfare concerns arise when animals are genetically modified for research or production.

Economic issues: GM seeds are often patented by large companies, meaning farmers must buy new seeds each year instead of saving seeds from their harvest. This can increase costs for farmers in developing countries and create dependence on seed companies.

Consumer choice: Many people want GM foods to be labelled so they can make informed choices about what they eat. Regulations vary between countries.

Writing a balanced evaluation

For extended-response questions, the examiner expects:

1. At least two specific benefits with biological explanations and named examples.
2. At least two specific risks or concerns with explanations.
3. A conclusion that weighs up both sides rather than simply stating "it depends".

Avoid vague statements like "it is unnatural" or "it could be dangerous". Instead, explain the specific mechanism of the risk: "herbicide-resistant genes could transfer to wild plants by cross-pollination, creating weeds that cannot be controlled by herbicides". Specificity is what distinguishes a good answer.

Try a focused question (6 marks)

Discuss the advantages and disadvantages of growing genetically modified crops.

Show the answer and marking guidance

Advantage: GM crops can be engineered for pest resistance (e.g. Bt crops produce a toxin that kills insect pests), reducing the need for chemical pesticides.
Advantage: Crops can be modified for higher yield or improved nutritional content (e.g. Golden Rice with vitamin A), helping to address food shortages and malnutrition.
Advantage: Herbicide-tolerant crops allow farmers to control weeds without damaging the crop, increasing efficiency.
Disadvantage: GM genes could transfer to wild plants by cross-pollination, creating herbicide-resistant weeds.
Disadvantage: Growing only a few GM varieties reduces genetic diversity, making crops vulnerable to new diseases.
Disadvantage: GM seeds are often patented, increasing costs for farmers who must buy new seeds each year.

Original Cambridge-style practice written for this site. It is not an official Cambridge past-paper question.

Common mix-ups to avoid

Check these points against your own answer before moving on.

Giving only advantages or only disadvantages when asked to "discuss" or "evaluate".
Using vague language like "it is bad for the environment" without a specific mechanism.
Confusing genetic modification with selective breeding.
Not providing named examples of GM organisms or their applications.
Forgetting to include a concluding statement in an extended-response answer.