Essay by roshan_n80University, Master'sA, February 2004

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Cloning is the production of a group of genetically identical cells or

organisms, all descended from a single individual. The members of a clone

have precisely the same characteristics, except where mutation and

environmentally caused developmental variation have occurred. The DNA is

precisley the same and they are only differentiated by their experiences in

which dictate their personality. There are some types of natural cloning

that nature displays. Some animals have tremendous powers of Regeneration.

If the body of certain starfishes is cut up into its five arms, each arm

will regenerate a complete individual. Another type of asexual reproduction

found in all animals, human beings included, is the formation of identical

twins, triplets, and so on. Identical siblings constitute a clone. The

growth of a tumor in the body of an individual is, in effect, the formation

of a clone of malignant cells. Humans have learned from nature and started

their cloning saga also.

In one method of artificial cloning used in plant

breeding, cells are cut from a plant and placed in a flask with a nutrient

medium. The cells grow and divide, forming embryonic tissues that are

transferred to soil, where they produce complete plants. Grafting is

another method of cloning used in Horticulture. Matching cuts are made in

the stems of two plants, which are then fitted together so that their

transport systems are in contact. The wounded area heals, and the two stems

become a single physiological unit. All the McIntosh apple trees now in use

and many other fruit varieties have been derived by grafting from single

ancestral trees. "Nuclear transplantation," in which nuclei from cells of

one individual are transferred to unfertilized eggs whose nuclei have been

removed, is one method of artificial cloning in animals. All the

transplanted nuclei are generally identical,