A clone is a plant organism, animal organism, individual cell, or an aggregate of cells which undergoes the process of cloning to reproduce asexually from a single progenitor cell, somatic cell, nucleus, or ancestor to which it is genetically identical. The word “cloning” may also refer to the duplication of any biological materials like cells or DNA. Although the cloned cells, organisms, or individuals share the same genetic material, it is not necessary that they appear identical.

Cloning occurs by nature and becomes fundamental to all living things. For example, Prokaryotic organisms (nuclei) like bacteria produce their genetically identical replicas through the process of binary fission, or budding. In eukaryotic organisms (organisms with a nucleus) like humans, cells undergo a process called mitosis to produce clones. Lastly, gamete cells (eggs and sperm) undergo different processes called meiosis, which involves genetic recombination.

The first artificial cloning was done in 1996 by British researchers who cloned an adult sheep to produce a lamb that they named Dolly. After Dolly, more animals were cloned such as pigs, monkeys, horses, rats, goats, mice, and dogs.

Reproductive cloning, gene cloning, and therapeutic cloning are the three different types of artificial cloning. Gene cloning is the process of producing identical copies of the genetic material such as genes or segments of DNA. Reproductive cloning produces copies of whole animals, and therapeutic cloning produces embryonic stem cells for experiments that are useful in treating injured or damaged cells.