Upload Now
In this article we will discuss about Cloning:- 1. Meaning of Cloning 2. Types of Cloning 3. Advantages 4. Disadvantages.
Meaning of Cloning:
The term cloning describes a number of different processes that can be used to produce genetically identical copies of a biological entity. The copied material, which has the same genetic makeup as the original, is referred to as a clone. Cloning in biotechnology refers to processes used to create copies of DNA fragments (molecular cloning), cells (cell cloning), or organisms.
a. British biologist J.B.S. Haldane is given credit for having coined the word “clone” during a speech in 1963.
b. In 1966, scientists Marshall Niremberg, Heinrich Mathaei, and Severo Ochoa broke the genetic code, allowing for studies on genetic engineering.
c. Dolly (5 July 1996 – 14 February 2003) was a female domestic sheep, and the first mammal to be cloned from an adult somatic cell, using the process of nuclear transfer.
d. On September 15, 2007, the Philippines announced its development of Southeast Asia’s first cloned water buffalo.
e. Since Dolly, researchers have cloned a number of large and small animals including sheep, goats, cows, mice, pigs, cats, rabbits, and a gaur. All these clones were created using nuclear transfer technology.
Types of Cloning:
1. Organism Cloning:
Organism cloning (also called reproductive cloning) refers to the procedure of creating a new multicellular organism, genetically identical to another. This form of cloning is an asexual method of reproduction, where fertilization or inter-gamete contact does not take place.
There is a lot of ethical debate over whether or not organism cloning should be used. However, this type of cloning or asexual propagation has been common practice in the horticultural world for hundreds of years.
2. Molecular Cloning:
Molecular cloning is a set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules and to direct their replication within host organisms. Molecular cloning takes advantage of the fact that the chemical structure of DNA is fundamentally the same in all living organisms.
In standard molecular cloning experiments, the cloning of any DNA fragment involves seven steps:
1. Choice of host organism and cloning vector
2. Preparation of vector DNA
3. Preparation of DNA to be cloned
4. Creation of recombinant DNA
5. Introduction of recombinant NA into host organism
6. Selection of organisms containing recombinant DNA
7. Screening for clones with desired DNA inserts and biological properties.
3. Cellular Cloning:
Cloning a cell means to derive a population of cells from a single cell. Somatic cell nuclear transfer (SCNT) can also be used to create embryos for research or therapeutic purposes. The most likely purpose for this method of cloning is to produce embryos for use in stem cell research.
Hence, it can also be termed as “research cloning” or “therapeutic cloning.” Recently, scientists at the New York Stem Cell Foundation Laboratory have reprogrammed an adult human egg cell to an embryonic state using cloning technology and created a self- reproducing line of embryonic stem cells from the developing embryo.
Advantages of Cloning:
1. Cloning of stem cells will provide treatment for variety of diseases.
2. It gives an opportunity to the parents to choose the characters and traits they want in their children and also eliminate the unwanted ones.
3. It provides a better understanding of the hereditary/genetic diseases.
4. The endangered species of various animals can be preserved and no risk of any extinction.
5. Provide organs for transplantation and also eliminates certain risks thus associated with the procedure of transplantation, so better life expectancy.
Disadvantages of Cloning:
1. Losing the diversity of genes.
2. It might be unethical and cause imbalance in the society.
3. Human cloning might pose the danger of human race extinction.