Genetic Engineering (Edexcel GCSE Biology: Combined Science)

• Genetic engineering is a process that involves modifying the genome of an organism to introduce desirable characteristics
• Specifically, genetic engineering is changing the genetic material of an organism by removing or altering genes within that organism, or by inserting genes from another organism
• The organism receiving the genetic material is said to be genetically modified or is described as being a transgenic organism
• The DNA of the organism that now contains DNA from another organism as well is known as recombinant DNA
• There are many examples of genetically modified organisms, including:
  • The gene for human insulin has been inserted into bacteria, which then produce human insulin that can be collected and purified for medical use for diabetics
  • Crop plants, such as wheat and maize, have been genetically modified to contain a gene from a bacterium that produces a poison that kills insects, making them resistant to insect pests such as caterpillars
  • Crop plants have also been genetically modified to make them resistant to certain herbicides (chemicals that kill plants), meaning that when the herbicide is sprayed on the crop it only kills weeds and does not affect the crop plant
  • Some crops have been genetically modified to produce additional vitamins, e.g. ‘golden rice’ contains genes from another plant and a bacterium which make the rice grains produce a chemical that is turned into vitamin A in the human body, which could help prevent vitamin A deficiency in certain areas of the world

Genetic engineering in medicine

• Modern medical research is exploring the possibility of genetic modification to overcome some inherited disorders
• As these inherited genetic diseases are caused by faulty genes, it may be possible to treat these by inserting working versions of these genes into people with the genetic disease
• This is called gene therapy