Clone (genetics)

From ArticleWorld

A clone is an identical replica of a macromolecule according to genetics. Cloning can be applied to all or part of a molecule. The cloning of a gene is to extract it from one organism and insert it into another. Cloning is also defined as the making of a genetically identical organism through non-sexual means.

Plant clones

Cloning in plants has been occurring naturally for millions of years. This has been by the method of reproduction that uses runners. The plant sends out a runner that takes root and a new plant forms. This occurs in many plants still such as potatoes, grasses and onions. These new plants are clones as they are genetically identical to the parent plant.

Clones of plants have also been created when people use cuttings to grow new plants in a process called vegetative propagation. The clones develop from cuttings as the ends of the cutting have a group of non-specialized cells called a callus. This can develop in to specialized structure on growth. Some new methods of plant clone production have developed. One of these is called tissue culture propagation. This uses root tip cells and cultures them into calluses which are then stimulated to grow.

Animal clones

In the animal kingdom there are also animals that use cloning as a reproductive means naturally. This occurs when the unfertilized eggs of some animals develop into adults usually due to some chemical stimulus. The offspring is a clone of the female that produced the egg. This is parthenogenesis. Natural clones are also seen in identical twins where they are genetically identical duplicates of one another.

Scientists have experimented with the production of clones of animals but are unable to form clones from the direct stimulation of a specialized cell. They instead transfer the genetic information from a specialized cell into an unfertilized egg which has had its genetic information destroyed and stimulate this to grow by fusing it with electricity. This method has been used to produce animal clones.

Why clone?

Cloning has been used to produce organisms with desirable qualities and has value to issues such as endangered species repopulation. Cloning however has initiated ethical debates with concerns that human cloning is unethical.