Facts About Human Cloning

There are two types of cloning. The first and most well known type of cloning is cloning to produce children, called “reproductive cloning.” The second type of cloning is cloning for biomedical research, known as “therapeutic cloning.”

 
Reproductive Cloning (cloning to produce children)
Humans may one day be able to be cloned using a procedure similar to the one used to generate Dolly the sheep. This kind of cloning involves taking the nucleus of a body (somatic) cell and introducing it into an egg cell (ovum) which has had its nucleus removed. The resultant cloned embryo is then implanted into a uterus to bring it to birth. The cloned embryo is an identical twin of the person who donated the starting somatic cell. Cloning is simply another approach to mimicking the biology that generates identical twins.

Therapeutic Cloning (cloning for research)
Therapeutic cloning involves making a cloned embryo by the same series of steps as reproductive cloning, but instead of implanting it into a uterus to be born, the embryo is destroyed to harvest its stem cells. Hence, therapeutic cloning is identical to reproductive cloning except for the final step. Therapeutic cloning is sometimes referred to as the “clone and kill” technique. The aim is to obtain rejection-proof stem cells for transplantation into the person from whom the clone was made. Because stem cells from the clone are actually from the identical twin of the person cloned, they should theoretically be a good match and not be rejected.