clone

Clone is a genetically identical copy of an organism, cell, or DNA sequence. The term can describe a natural process or a laboratory technique. In biotechnology, cloning usually refers to molecular cloning (copying DNA fragments) or reproductive cloning (creating a living organism with the same genome as the donor).

Molecular cloning uses a DNA fragment inserted into a vector, such as a plasmid, propagated in a host cell to produce multiple copies. Reproductive cloning aims to create an animal identical to the donor, commonly through embryo splitting or somatic cell nuclear transfer. Dolly the sheep, created in 1996, demonstrated this capability in mammals. Therapeutic cloning is related but seeks to derive pluripotent stem cells for medical use, not a cloned animal.

Cloning occurs naturally in asexually reproducing organisms and in plants by cuttings or grafts, yielding true copies. In labs and industry, cloning underpins genetic engineering, agriculture, and lab-grown cell lines, including cloned genes and proteins.

Ethical and regulatory debates cover safety, animal welfare, germline modification, and the implications of human cloning. Laws vary by country, with many prohibiting reproductive cloning while permitting certain forms of research.