Cloning

Cloning

1. Tissue Culture

   • 1) Parent plant with desired characteristics is selected
     • 2) A few cells are scraped off into several beakers containing nutrients and hormones
       • 3) A week or two later there are lots of genetically identical plants growing
   • The process must be aseptic (carried out in the absence of harmful bacteria) otherwise the plants will rot

2. Embryo Transplants

   • 1) Parents with desired characteristics are mated
     • 2) Embryo is removed before the cells become specialised
       • 3) Then they are split into several clumps
         • 4) These embryos are implanted into the uterus of sheep who will give birth to the clones
   • The offspring are genetically identical to each other but not to the parents

3. Adult cell cloning

   • 1) An egg is taken from an ovary of sheep A
     • 2) A cell is taken from the udder of sheep B
       • 3) The egg is enucleated (no nucleus)
         • 4) The udder cell and the enucleated egg are fused with electricity
           • 5) Now an egg has been made that contains DNA from sheep B
             • 6) Cell division happens until an embryo is formed
               • 7) The embryo is implanted into the uterus of sheep A
                 • 8)A sheep is born with the DNA from sheep B (a clone of sheep B)

4. Genetic Engineering

   • 1) An enzyme is used to cut a chromosome so DNA can be removed
     • 2) Another enzyme is used to cut open a bacterial DNA (plasmid)
       • 3) Enzymes are used to insert the piece of human DNA into the plasmid
         • 4) The plasmid is reinserted into a bacterium which divides rapidly
   • Benefits: plants and animals can be modified to have desired characteristics
   • Disadvantages: costly and a single mistake could create a new genetic disorder, for example.