Genetic Engineering (OCR Gateway GCSE Biology: Combined Science)

• Food production can be intensified (making more food with fewer resources) by an artificial process called genetic engineering
• This involves taking genes from one organism and placing them into the cells of another organism (another species)
  • In doing so, this gives the new organism a new characteristic that it would not have developed naturally
• Genetic engineering can be defined as follows:
  • A process which 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
  • Often referred to as 'GM' or 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

Benefits and risks of genetic engineering of food products

• Benefits:
  • Improvement of crop yields (see above)
  • Making crops more nutritious to fight deficiency diseases
• Risks
  • Possible spread of genes to wild plants
    • e.g. a herbicide-resistance gene getting into other plants, creating 'superweeds'
  • Unknown effects on human health of GM crops
  • Religious and ethical concerns about tampering with nature
    • Do animals suffer in the process?
    • Are we likely to go on and engineer ourselves genetically, creating a 'genetic underclass'
  • Knock-on effects on associated wildlife, reducing the biodiversity of agricultural land
  • The general level of uncertainty about genetic engineering and the possible unforeseen complications that it might uncover