ABSTRACT
To appreciate the techniques involved in cloning one must understand the differences between the two cell types, somatic cells and gametes, and the two types of cell division, mitosis and meiosis. In humans and other mammals, identical twins are natural clones. For both natural clones and those obtained by embryo splitting, the characteristics of the clones are predictable only within certain limits. The only way to obtain an exact copy of an adult organism with specific genetic characteristics is to clone it by nuclear transplantation. Cloning by nuclear transplantation will broaden the range of species that can be used for such research, and the results may be more directly relevant to human pathology. Cell lines established from the "best" animals could be used to derive flocks or herds of clones that would be genetically identical and all have the desired traits for high-performance characteristics.
