It may be helpful to start a discussion of the ethical issues posed by the topic of cloning by defining some terms:
A clone is an organism that is identical in genetic composition to another organism. Clones are usually produced by asexual reproduction, but new techniques of cell biology have enabled the laboratory production of clones by transplantation of the nucleus. See the basic process on the next page.
Stem cells are the cells of the early embryo from which all the cells in the adult body will develop. They are said to be totipotent. The term stem cell has also been used for other undifferentiated cells in the body, for example in the bone marrow. However, these cells can only differentiate into types of blood cell, and are said to be pluripotent.