Genetic engineering is a process that modifies the genome of an organism by introducing a gene from another organism, to give a desired characteristic. Genes from the chromosomes of humans and other organisms can be cut out and transferred to the cells of other organisms.
In agriculture, crops that have had their genes modified in this way are called genetically modified (GM) crops. GM crops include ones that are resistant to insect attack or to herbicides, and some produce bigger, better fruits. GM crops generally show increased yields. In medicine, bacterial cells have been genetically engineered to produce useful substances such as human insulin to treat diabetes. Research is also exploring genetic modification to overcome some inherited disorders.
Some people object to genetic engineering. Concerns about GM crops include the effect on populations of wild flowers and insects. Some people feel the effects of eating GM crops on human health have not been fully explored.
Higher tier only: enzymes are used to isolate the required gene. The gene is inserted into a vector, usually a bacterial plasmid or a virus. The vector inserts the gene into the required cells. Genes are transferred to the cells of animals, plants or microorganisms at an early stage in their development, so that they develop with the desired characteristics.
