Genetic modification case study

Are genetically modified crops a good or a bad thing? Read on and decide for yourself about this population problem

Background briefing

Many scientists claim that genetically modified (GM) crops will contribute to feeding a larger population more sustainably, though anti-GM campaigners disagree.

North and South America:

In the USA, where 40 per cent of GM crops are grown, a type of pest-resistant GM corn was removed from sale because it was thought that the bacterial genes it contained might cause allergies.

Brazil grows 23 per cent of the world’s GM crops, while Argentina grows 14 per cent. Concerns are not just related to consumer safety, but also to the effects of GM crops on agricultural ecosystems. For example, one GM cotton crop that was created to tolerate a particular weedkiller resulted in the growth of super-weeds that became resistant to the weedkiller after farmers started applying it too heavily.


GM crops are hardly grown at all. This is partly due to the perception among some consumers that GM foods are unnatural and potentially unsafe. There is no clear evidence that the risks associated with eating GM foods are greater than for non-GM foods.

In a 2012 Wellcome Monitor survey here in the UK, 90 per cent of adults and 83 per cent of young people had heard of the germ ‘GM’/‘genetically modified’, but only 34 per cent thought they had a very good or good understanding of it. A quarter of adults thought that by eating GM fruit, a person’s genes could also become modified, while just under a third of young people thought the same.


Plantings of GM food crops are small, but Bt cotton is very popular. There is mistrust of the companies that sell GM products because the seeds are expensive, making it difficult for farmers from low- and middle-income countries to afford them.


Scientists engineer a new type of Cavendish banana that is resistant to Panama disease.

  • Would you be happy to eat GM bananas? Why or why not?
  • What are the benefits and risks for farmers, for consumers and to biodiversity of switching to the GM crop?
  • Who owns these new varieties? Who should own them?

About this resource

This resource was first published in ‘Populations’ in June 2014.

Ecology and environment
Education levels:
16–19, Continuing professional development