Genetic engineering and genetic modification are relatively recent terms but humans have been genetically modifying animals and plants using selective breeding for thousands of years. Genes can also change without human intervention. This is known as mutation. Debating the arguments for and against GM ingredients provides opportunities to discuss how and why decisions about science are made and the related ethical issues. These discussions can also provide the opportunity to show that there are some questions that science cannot currently answer.

Assessable learning outcomes

Both tiers:

Describe the process of selective breeding involving the:

• selection characteristics;
• cross breeding;
• selection of suitable offspring over many generations

Explain how selective breeding can contribute to improved agricultural yields.

Explain some potential advantages and risks of genetic engineering and selective breeding:

• advantage - production of organisms with new features;
• disadvantage - inserted genes may have unexpected harmful effects

Describe, in outline only, some examples of genetic engineering:

• transferring resistance to herbicides, frost damage or disease to crop plants

Higher Tier only:

Explain that a selective breeding programme may reduce the gene pool leading to problems of inbreeding:

• accumulation of harmful recessive characteristics;
• reduction in variation

Discuss the moral and ethical issues involved in genetic modification weighed against the potential benefits.