Section B3g: Living and Growing - New Genes for Old

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.

Suggested activities and experiences to select from:

Research examples of different animal and plant breeds that have been produced by selective breeding.

Assessable learning outcomes:

Foundation Tier only:
Recognise features of plants and animals that might be selected for enhancement in a breeding programme.
State that genes can be transferred from one living organism to another and that this is called genetic engineering or genetic modification. Recognise features of plants and animals that might be selected for in a genetic engineering programme.

Both tiers:
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:

• Taking the genes from carrots that control beta-carotene production and putting them into rice. Humans can then convert the beta-carotene from rice into Vitamin A (solving the problem of parts of the world relying on rice but lacking in vitamin A);
• the production of human insulin by genetically engineered bacteria;

Higher Tier only:
Describe the principles of genetic engineering:

• selection of characteristics;
• isolation of genes;
• insertion;
• replication

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

Section B6h: Beyond the Microscope - Genetic Engineering

Biotechnology is "using life to make things". Genetic engineering has the potential to alter life on Earth in a very short time span by transferring genes from one organism to another. The advantages are enormous, the long term risks high.

Assessable learning outcomes:

Foundation Tier only:

• State that genetic engineering alters the genetic code of an organism
• State that genes from one organism will work in another organism

State that genetic engineering involves:

• removing a gene from one organism;
• inserting it into another organism;
• the gene works in the new organism

Both tiers:
Recall that genetic engineering alters the genetic code of an organism by inserting genes.
Recall that the new type of organism is called a transgenic organism.

Describe the main stages in genetic engineering:

• identification of a desired gene in one organism;
• removal of gene from DNA;
• cutting open the DNA in another organism;
• inserting the new gene into the DNA;
• gene works in transgenic organism;
• transgenic organism is then cloned to produce identical copies

Describe how bacteria can be used in genetic engineering, for example, to produce human insulin:

• gene for producing human insulin cut out of human DNA;
• loops of bacterial DNA called plasmids cut open;
• insulin gene inserted into plasmid;
• transgenic bacteria cultured by cloning;
• large quantities of insulin harvested

Higher Tier only:
Describe how restriction enzymes cut open DNA and ligase enzymes rejoin DNA strands.
State that assaying techniques are used to check that the new gene has been correctly transferred.