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Cloning is the process of making an identical copy of something. It refers to processes used to create copies of DNA fragments, be it molecular cloning or cell cloning or organisms. The term also covers when organisms such as bacteria, insects or plants reproduce asexually.

The possibility of human cloning was raised when scientists at Roslin Institute created the much-celebrated sheep called Dolly. It aroused worldwide interest and concern because of its scientific and ethical implications. The immediate reaction was that humans would now be able to make brand-new copies of themselves. This breakthrough in 1997 also generated uncertainty over the meaning of cloning'. There are three types of cloning. They are DNA cloning, reproductive cloning and therapeutic cloning.

Recombinant DNA technology or DNA cloning involves the transfer of a DNA fragment from one organism to a self-replicating genetic element. Scientists studying a particular gene often use bacterial plasmids to generate multiple copies of the same gene. Plasmids are self-replicating extra-chromosomal circular DNA molecules. When the fragment of the chromosomal DNA is joined with its cloning vector in the lab, it is called a recombinant DNA molecule.

Reproductive cloning is a technology used to generate an animal that has the same nuclear DNA as another currently or previously existing animal. Dolly was created by this type of cloning technology. In the process, scientists transfer genetic material from the nucleus of a donor adult cell to an egg whose genetic material has been removed. The reconstructed egg containing the DNA from a donor cell must be treated with chemicals or 'electric current to stimulate cell division. Once the cloned embryo reaches a suitable stage, it is transferred to the uterus of a female host where it continues to develop until birth.

Therapeutic cloning is also called `embryo cloning'. It is the production of human embryos for use in research. The goal of this process is not to create cloned human beings but rather to harvest stem cells that can be used to treat disease. Stem cells are important to biomedical researchers because they can be used to generate virtually any type of specialised cell in the human body.

Stem cells are extracted from the egg after it has divided for five days. The extraction process destroys the embryo, which raises a variety of ethical concerns. It is hoped that one day, stem cells can be used to serve as replacement cells to treat heart disease, Alzheimer's, cancer and other diseases.

Recombinant DNA technology is useful for learning about other related technologies such as gene therapy and genetic engineering of organisms. Gene therapy can be used to treat certain genetic conditions by introducing virus vectors that transfer corrected copies of faulty genes into the cells of a host organism. Similarly, genes from different organisms can be used to improve taste and nutritional value or provide resistance to particular types of disease or genetically engineer food crops.

 

Based on the passage given, write a summary on :

the process of cloning

three types of cloning and their uses

 

Your summary must:

be in continuous writing ( not in note form )

not be longer than 130 words, including the 10 words given below

 

Begin your summary as follow:

Cloning is the process of making identical DNA fragments or ...

 
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Answer
 
Cloning is the process of making identical DNA fragments or organisms. DNA cloning involves the transfer of a DNA fragment from one organism to the same gene. Reproductive cloning can generate an animal that has the same DNA. The immediate reaction of the cloning of Dolly was that we could make brand-new copies of ourselves. The reconstructed egg is treated to stimulate cell division. Therapeutic cloning is the production of human embryos for use in research. The goal is to harvest stem cells to treat heart disease, Alzheimer's, cancer and other diseases. They are important in biomedical research. Recombinant DNA technology is useful to learn about gene therapy and genetic engineering of organisms. Gene therapy is used to provide resistance to particular types of disease and genetically engineer food crops. (126 words)
     
 
 

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