Cloning

=  ﻿ ﻿Cloning =

What is cloning? Cloning is the creation of an organism that is genetically exact copy of another. So both DNA’s strands are exactly the same.

Cloning is one section of genetic engineering, where duplicate copies of pre-existing organisms are created through the use of a variety of methods (http://library.thinkquest.org/19697/). In one, the female egg is “made to behave” like a zygote through a stimulus such as “chemicals or electricity.” This process is called ‘parthenogenesis’

**Embryo Cloning**:This is a medical technique which produces identical twins or triplets. It duplicates the process that nature uses to produce twins or triplets. One or more cells are removed from a fertilized embryo and encouraged to develop into one or more duplicate embryos. These twims or triplets have an identical DNA. There has been very little to none ersearc on humans.

**Reproductive Cloning**: This technique which is intended to produce a duplicate of an existing animal. It has been used to clone a sheep and other mammals. The DNA from an ovum is removed and placed with the DNA from a cell removed from an adult animal. Then, the fertilized ovum or a pre-embryo, is implanted in a womb and allowed to develop normally into a new animal. Many medical ethicists consider it to be a profoundly immoral procedure when done on humans, it is forbidden by law in many countries.

**Dolly** “the most famous sheep” was a domestic sheep that was born on July 5th of 1996 and died six years later, on February 14th of 2003. She was the first mammal to be cloned. From an adult somatic cell (any cells forming the body of an organism) by a nuclear transfer (type of cloning). His creators were Ian Wilmut (1944), Keith Campbell (1954 and colleges. Dolly was born and lived in Scotland at the Roslin Institute. Dolly had three mothers:  -one provided the egg  - the second  -and the third carried the cloned embryo to term  Also, Dolly was a mother of 6 lambs:  - The first time she had was Bonnie (1998)  - The second time Sally and Rossie (twins)  - And the third time she had Lucy, Darcy and Cotton (triplets)

At the age of five (2001), Dolly had arthritis and her pain was treated with anti-inflammatory drugs. She died with severe arthritis and cancer lung called Jaagsiekte (common in sheeps).

**Therapeutic cloning:** During therapeutic cloning, the initial stages are identical to adult DNA cloning. However, the stem cells are removed from the pre-embryo with the intention of producing tissue or a whole organ for transplant back into the person who supplied the DNA. The pre-embryo dies in the process. This process is used to create a healthy copy of a sick person's tissue or organ for transplant.

There are ethical problems when any of these three techiniques are applied to humans.

Disadvantages of cloning: Cloning means all humans beings is identical, which means that if we will do a cloning experiments on human, all humans will be at risk of getting infected by the same type of pathogen. This means that if everyone had the same gene type, their inmune systems wouldn't be able to defend to some types of diseases. If there are different people then there will always be a group of people that can defend themselves from most bacteria or diseases. Another disadvantage is that it’s inhuman to clone a human. A human clone can be even better than its original innkeeper which turns us to properties that can be sold to anyone. Advantages of cloning: With the process of cloning we can help the animals and species from facing extinction

([|[[http://www.arhp.org/publications-and-resources/patient-resources/printed-materials/cloning|http://www.arhp.org/publications-a]]]nd-resources/patient-resources/printed-materials/cloning).

 @http://en.wikipedia.org/wiki/Dolly_%28sheep%29