In 1997, Dolly the sheep became the first mammal to be successfully cloned. The cloning required an astonishing 277 trials that produced only 29 embryos, among which only one birth survived.
The rapid advancements in science and technology over the last couple of decades has meant that mankind is exploring newer frontiers and challenging long-held beliefs and notions. One such field is cloning. Creating exact copies or cloning human beings has always fired the human imagination. This desire has manifested itself in various art and entertainment depicting cloned humans. The successful cloning of 'Dolly' in 1997 further fueled talk about the possibility of human cloning. Over the years, cloning has come to mean an artificial and identical genetic copy of an existing life form.
To explain in a scientific way, cloning means replacing the egg nucleus of an organism with the donor's nucleus. This nucleus contains unique genes of the donor. The procedure involves removing the nucleus of a somatic cell and inserting it into an enucleated or unfertilized egg cell. Unlike natural reproduction, wherein the egg contains a combination of genetic material, this egg which grows into an embryo contains only the donor's gene.