Cloning

From ArticleWorld

Cloning can be defined as the creation of an identical copy. It is therefore the production of a cell of multi-cellular organism that is genetically identical to another organism. This organism would be referred to as a clone of the original organism. In nature there are natural clones when asexual reproduction occurs and when genetically identical individuals are produced as in twins. It is however now common to associate the term clone to mean an identical copy that is created by some conscious means.

Cloning of plants and animals

The cloning of plants has been occurring for millions of years. Natural plant clones include runners as well as leaf cuttings. The use of leaf cuttings is also termed vegetative propagation. The cuttings develop into new plants due to the presence of unspecialized cells that form a group known as a callus. These can grow into specialized cells upon development. In plants, new methods are being used for cloning. One of these is called tissue culture propagation and uses the root tip cells. These cells develop into a callus and are stimulated to grow by the use of hormones to produce clones.

Animal cloning also can occur naturally under some chemical conditions where egg cells that are unfertilized can develop into mature adults. This process is parthenogenesis and results in a clone of the female that produced the egg. Clones also arise in the formation of identical twins. Experimentation into animal cloning is now a large field. Cloning in animals cannot occur from the stimulation of specialized cells but must be done in an alternative method. The concept behind this is based on the use of the nucleus from a specialized cell being inserted into an unfertilized egg in which the genetic information is removed. This cell is then exposed to electricity to stimulate fusion and then development can result.

Ethical issues

There are concerns mainly about human cloning. The technology for cloning has developed to the extent that human cloning is now thought possible by many. The Roman Catholic Church is opposed to human cloning as they believe that once fertilization occurs, an embryo constitutes a person.