CLONING

In biology, cloning is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria,insects or plants reproduce asexually.

  Cloning in biotechnology refers to processes used to create copies of DNA fragments (molecular cloning), cells (cell cloning), or organism. The term also refers to the production of multiple copies of a product such as digital media or software.

Clones are organisms that are exact genetic copies. Every single bit of their DNA is identical. Clones can happen naturally, identical twins are just one of many examples. Or they can be made in the lab. 

The term clone is derived from the Ancient Greek word which means "twig", referring to the process whereby a new plant can be created from a twig.

In horticulture, the spelling clon was used until the twentieth century; the final e came into use to indicate the vowel is a "long O" instead of a "short O". Since the term entered the popular lexicon in a more general context, the spelling clone has been used exclusively. In botany, lusus was the word which was traditionally used.

Cloning was first experimented on dolly the sheep. Artificial cloning technologies have been around for much longer than Dolly, though.

There are three types of cloning:

·       Molecular Cloning­- It involves making of multiple molecules. Initially, the DNA of interest needs to be isolated to provide a DNA segment of suitable size. Subsequently, a ligation procedure is used where the amplified fragment is inserted into a vector . The vector is linearised, and incubated with the fragment of interest under appropriate conditions with an enzyme. Following ligation the vector with the insert of interest is transfected into cells. Finally, the transfected cells are cultured. As the aforementioned procedures are of particularly low efficiency, there is a need to identify the cells that have been successfully transfected with the vector construct containing the desired insertion sequence in the required orientation.

Cell cloning-In the case of unicellular organisms, this process is simple and essentially only requires the inoculation of the appropriate medium. However, in the case of cell cultures from multi-cellular organisms, cell cloning is an arduous task as these cells will not readily grow in standard media.

A useful tissue culture technique used to clone distinct lineages of cell lines involves the use of cloning rings (cylinders). According to this technique, a single-cell suspension of cells that have been exposed to a mutagenic agent or drug used to drive selection is plated at high dilution to create isolated colonies, each arising from a single and potentially clonal distinct cell.

Somatic-cell nuclear transfer can also be used to create embryos for research or therapeutic purposes. The most likely purpose for this is to produce embryos for use in stem cell research. This process is also called "research cloning" or "therapeutic cloning." The goal is to harvest stem cells that can be used to study human development and to potentially treat disease. While a clonal human blastocyst has been created, stem cell lines are yet to be isolated from a clonal source.

Organism Cloning-It involves creating a new multicellular organism which are genetically identical to each other. It is asexual method of reproduction(which is naturally occurring phenomenon in many species). Scientists have achieved many achievements in field of cloning, including asexual reproduction of cows and sheeps like dolly the sheep. Cloning has been common practice in the horticultural world for hundreds of years.

 So, at last I would say that we can’t decide that cloning is useful or harmful.