Stem cells are the cells that are able to reproduce themselves using the process of cell division. Stem cells also do not have a function, but they are capable of developing into cells with more specialized functions. There are three types of stem cells, which are: embryonic stem cells, embryonic "fetal" germ cells, and adult stem cells. Embryonic stem cells come from embryos (organisms that are in their earliest stage of development). Adult stem cells come from adult organ or tissue. There is a big debate going on about the issue of using the embryonic cells to cure various diseases, discovering more about birth defects, and producing new genes that could prevent birth defects. One side of the debate views the use of the embryonic cells as "the killing of the seeds of a new generation" and proposes using the adult stem cells instead. The other side of...