The second path, which is the path that we are advocating, would be to use the cells to create specific cell types that a particular patient needs. But the pre-embryo, in and of itself, doesn't spontaneously form wanted tissues. You would have to coax the pre-embryo cells to turn into the types of cells you want to form. We believe that all of this could be done in tissue culture, growing individual cells, without creating a cloned human being. Young and old cells show dramatic differences.
Cloning can convert old cells into young cells.
Technically, an embryonic stem cell is a cultured inner cell mass. So the blastocyst is a little ball of cells, and inside it is a cluster of cells called the inner cell mass, and surrounding them is a shell of cells called the trophectoderm. The trophectoderm will become the placenta, and the inner cell mass will become the entire animal or, in the case of humans, the entire human being. The inner cell mass cells are totipotent. They have complete power.