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Cloning Essay

Autor:   •  March 8, 2011  •  Essay  •  1,175 Words (5 Pages)  •  2,012 Views

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On July 5, 1996, a sheep named Dolly was born in the Roslin Institute in Edinburgh, Scotland. Dolly was the first clone of a mammal from an adult cell. Dolly was not, however the world's first attempt at cloning, which began at the beginning of the century. (10) The birth of Dolly also introduced the birth of the possibility of another idea: the cloning of human beings This gave rise to controversy and the question of whether cloning humans was morally right.

There are two different methods or ways to clone. One way is known as embryo cloning, which is also known as 'artificial twinning' because it resembles the process in which twins develop. "Human embryo cloning starts with a standard in vitro fertilization procedure. Sperm and an egg cell are mixed together on a glass dish. After conception, the zygote (fertilized egg) is allowed to develop into a blastula (a hollow mass of cells). The zygote divides first into two cells, then four, then eight... A chemical is added to the dish to remove the "zona pellucida" covering. This material provides nutrients to the cells to promote cell division. With the covering removed, the blastula is divided into individual cells which are deposited on individual dishes. They are then coated with an artificial zona pellucida and allowed to divide and develop. The experiment by Sillman et al. showed that the best results could be obtained by interrupting the zygote at the two cell stage. Many of these pairs of zygotes were able to develop to the 32 cell stage, but no further. They might well have had the potential to develop further and even mature into a viable fetus, except that the original ovum was defective and would have died anyway." (4)

The other form of cloning is known as Adult DNA cloning which was what was done in the case of Dolly. "...a cell was taken from mammary tissue of a mature 6 year old sheep while its DNA was in a dormant state. It was fused with a sheep ovum which had had its nucleus removed. The "fertilized" cell was then stimulated with an electric pulse. Out of 277 attempts at cell fusion, only 29 began to divide. These were all implanted in ewes. 13 became pregnant but only one lamb, Dolly, was born." (4)

There are certain medical benefits to cloning. First of all, we will now be able to replace damaged cells with new cells. Second, we will also be able to create human beings who will be able to act as organ donors. Third, Couples who are unable to conceive children will still be able to have children with their genes. (13) By cloning, treatments for diseases that involve damaged cells that are unable to replace themselves, (Parkinson's Disease, diabetes and muscular dystrophy) can be found. (7)

A CNN poll interviewed 1005 Americans in 1997. (4) The results were as follows:

* 89% believed that the

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