Genetic modification

• Selective breeding/artificial selection

  • individuals with desirable characteristics are bred together.
  • offspring with the same characteristics are bred until a new species is created.
  • leads to inbreeding and a reduced gene pool
  • animal- chickens that lay big eggs, fast horses, sheep with good quality wool
  • plant- good crop yeild, disease resistance, weather tolerance
• Tissue cultures 


  Small pieces of organisms are grown using nutrient media
• Plant tissue cultures

  1. parent plant is chosen
  2. small explant is taken from the parent plant
  3. explant is transfered to a sterile petri dish containing nutrient agar
  4. hormones are added to aid growth
  5. plantlets form
  6. plantlets are transferred into a potting tray with compost to enable them to continue to grow.
• Why are plant tissue cultures used in mass production?

  1. High crop yield
  2. low risk of disease
  3. can be completed anytime of year
  4. quick
  5. cheap
• Animal tissue culture


  Genetically identical animal cells are produced for medical examination/research.
• Animal tissue cultures

  1. Tissue extracted from animal
  2. Enzymes are used to separate the cells
  3. Cells are placed in the culture vessel along with a growth medium
  4. Once grown, the culture is stored
• Genetic engineering

  Modifying the genome of an organism to introduce desirable characteristics
• What is DNA that contains DNA from another organism known as?

  recombinant DNA
• What is an organism receiving the genetic material called?

  Transgenic organism
• How can insulin be genetically modified?

  It can be injected into bacteria, which produces insulin for people with diabetes
• What is special about golden rice?

  it is modified to have extra vitamin c
• The Process of genetic engineering

  1. Required gene is located within the original organism.
  2. Restriction enzymes isolate the required gene, leaving it with sticky ends.
  3. A bacterial plasmid is cut with the same enzyme laving it with corresponding sticky ends.
  4. The plasmid and gene are stuck together using a DNA ligase enzyme, forming an unbroken molecule of DNA.
  5. New plasmid is inserted into a bacteria cell.
  6. Bacteria is reproduced with the same plasmid containing the recombinant plasmid.
  7. Can be placed in a fermenter to reproduce in controlled conditions
• What is sticky ends?

  A short section of unbonded bases of dna