Zusammenfassung der Ressource
Cloning
- 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
- 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
- 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)
- 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.