How would human cloning work?
Scientists believe that human cloning would involve the following steps: • A somatic cell (as opposed to a germ cell, or egg) is taken from a woman donor. • An unfertilized egg is retrieved from a second woman. • The nucleus of the unfertilized egg is removed. (The egg is now enucleate.) • The nucleus of the somatic cell is removed and transferred to the enucleated egg. Thus, the somatic-cell nucleus has replaced the nucleus of the egg cell. • The egg is now implanted into the uterus of a surrogate mother, where it develops into a fetus. • The resulting baby is genetically identical to the original cell donor. You may be wondering why all of these steps involving the transfer of nuclei are necessary. Normally, when an embryo develops, it is formed from the fusion of an egg and a sperm. Egg and sperm cells are each haploid (they contain only one copy of each gene). When they fuse, the resulting embryo is diploid (it contains two copies of each gene, and its complement of genetic materia
