5.6- Applications of Reproduction and Genetics

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  • Created by: Rebecca
  • Created on: 21-06-11 13:06

Cloning:

  • Clones are asexually reproduced, hence genetically identical.
  • Cloning can occue natural, for exmaple in bacteria, yeast, and plants grown from suckers, bulbs and corms.
  • Artificial clones can be formed in animals by separating embryos at an early stage.
  • Artificial plant clones can be formed by taking cuttings and performing micropropagation.

Cloning Animals- Embryo Cloning:

  • This technique has been used to produce genetically identical individuals, and has made it possibly for farmers to dramatically increase the number of animals. 
  •  Eggs are taken from high milk yielding cows and are fertilised in a petri dish using sperm from the best bulls.
  •  This is known as in vitro fertilisation (IVF or Test-Tube Fertilisation). 
  • The fertilised egg divides to form a ball of cells. 
  • This group of cells or young embryo are split into separate cells. Each of these cells then develop into a new embryo, genetically identical to the original. 
  • The embryos are then transplanted into other cows called surrogates. 
  • As well as increasing the farmer's stock, this technique is also used to preserve rare breeds where the embryo of the rare breed is split and transplanted into a surrogate common breed.

Cloning Animals- Cloning by Nuclear Transplants:

  • This technique allows clones to be produced from one individual. 
  • It involves transplanting a nucleus from a somatic cell into an egg cell. 
  • Cells are taken from the tissues of the udder of a sheep (the donor) and cultured in a medium which stops division.
  • An unfertilised egg is removed from a different sheep (the recipient) and the nucleus is removed leaving an egg cell without  a nucleus.
  • The donor and recipient cells are fused together and allowed to divide producing a ball of cells.
  • The developing embryo is implanted into the uterus of another sheep (the host or surrogate).
  • The lamb born is genetically identical to the original donor sheep.
  • This technique has enabled desirable qualities to be preserved for future generations.
  • Cloning means that if, for example, a mutation occurs in a cow that means she yields much more milk than the rest of her herd, she can be cloned, as this is the only technique that

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