Genetic engineering is also called genetic modification or GM. It involves modifying the genome of an organism by identifying and removing a gene from the genome of one organism, and introducing it into the genome of another organism to result in a desired characteristic. Genetic engineering can make faster changes to organisms than selective breeding.
Genetic engineering involves these steps:
Plant crops have been genetically engineered to be disease resistant or to produce bigger fruits.
Diabetes is a disorder in which the body's blood glucose levels remain too low or too high. It can be treated by injecting insulin. The extra insulin allows the glucose to be taken up by the liver and other tissues, which results in cells receiving the glucose they need, and blood glucose levels staying normal.
Bacterial cells have been genetically modified to produce substances such as human insulin.
Scientists have added a gene to wild rice that makes it produce beta carotene. This changes the colour of the wild rice to a golden colour. Beta carotene is needed by humans in order to make vitamin A - which is essential for good vision.
The advantage of golden rice is that it can be used in areas where vitamin A deficiency is common, so it can help prevent blindness. In many countries golden rice is not being grown commercially over fears associated with genetically modified crops.
There are ethical issues involved in genetic modification, as well as concerns about the possible health risks of genetically modified food. For example, a GM food might contain a substance that causes an allergic reaction in some people, or higher levels of a toxin naturally found in the food. Others think it is ethically wrong to create new life forms, or to move genes between different species.