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The biology of cloning.

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AS level Biology Coursework Cloning Cloning has received a lot of interest recently, with the death of Dolly the sheep, 'the first mammal ever created from the non-reproductive tissue of an adult animal', and whether her death had anything to do with the fact that she was a clone, as well as the current rumours over human clones and the moral issues involved with it. Cloning involves a process called nuclear transfer, which was first explored by Spemann in the 1920's to conduct genetics research. All cloning experiments of adult mammals have used a variation of nuclear transfer. Nuclear transfer requires two cells, a donor cell and an oocyte, or egg cell. Research has proven that the egg cell works best if it is unfertilized, because it is more likely to accept the donor nucleus as its own. The egg cell must be enucleated. The nucleus is removed from the egg cell. This removes the majority of its genetic information. The donor cell is then forced into the Gap Zero, or G0 cell stage, a dormant phase, in different ways depending on the technique. ...read more.


was selected from the udder cells of a Finn Dorset sheep to provide the genetic information for the clone. For this experiment, the researchers allowed the cell to divide and form a culture in vitro, or outside of an animal. This produced multiple copies of the same nucleus. This step only becomes useful when the DNA is altered, such as in the case of Dolly, because then the changes can be studied to make sure that they have taken effect. * The donor cell is grown in a Petri/culture dish. * A donor cell was taken from the culture and then starved in a mixture which had only enough nutrients to keep the cell alive. * This culture dish barely has enough nutrients to keep the cell alive. * This caused the cell to begin shutting down all active genes and enter the G0 stage. The egg cell of a Blackface ewe was then enucleated and placed next to the donor cell. One to eight hours after the removal of the egg cell, an electric pulse was used to fuse the two cells together and, at the same time, activate the development of an embryo. ...read more.


They also feel we are taking 'Gods' work into our own hands, 'For the first time we are not faced with the lamb of God, but the Lamb of Man' - Daily Mail Feb 14 1997. Human cloning is currently illegal in Britain, however, there are many countries in which it is not against the law. People are now worried of the dangers of cloning because of the apparent premature aging and the death of Dolly the sheep, as well as the number of failures it took before Dolly was created. This in itself holds major moral issues against the cloning of humans. Dr Wilmut himself, creator of Dolly has blasted ideas of human cloning, describing it as 'extremely cruel'. He warned that four years of experiments on animals had shown the cloning technique to be deeply flawed, with many miscarriages and deformities. It is uneasy to see now what future outcomes cloning may bring, but it easy to see it could have many positive effects, such as the treatment of diseases, but I believe a line must be drawn when we are moving from necessity to convenience and into the realm of genetically enhanced livestock and designer babies. 1 ...read more.

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