modification

• selective breeding


  breeding plants and animals for specific genetic characteristics
• selective breeding

  • decide which characteristic is important
  • choose parents that show the characteristic the most and breed them
  • the offspring that have the characteristic are bred together
  • repeat over generations until all offspring have the characteristic
• selective breeding pros

  • you can breed disease resistance
  • can produce animals with more meat or milk
  • more profit for farmers
• selective breeding cons

  • interferes with natural selection
  • chance of inbreeding
  • no variation in the population
• genetic engineering


  modifying the DNA of an animal or plant to create a characteristic
• genetic engineering pros

  • can be used to produce medicine e.g insulin
  • can produce animals with suitable organs for human organ transplant
  • can be used to modify crops to be resistant to droughts (no water)
• genetic engineering cons

  • difficult to predict its effects on an organism
  • its use in agriculture and medicine may effect humans
  • genes from crops could get into the environment and cause superweeds
• genetic engineering for insulin

  • section of insulin gene is cut out using restriction enzymes
  • plasmid is removed from the bacteria cell and cut using restriction enzymes, forming complementary ends
  • insulin gene is placed into the plasmid using DNA ligase
  • genetically modified plasmid is put back into the bacteria cell
  • bacteria cell multiplys , passing on the modification
  • insulin is removed from the fermenter