the embryonic staircase? Totipotent stem cells are capable of producing all tissue, including the trophoblast necessary for implantation. Totipotent stem cells have the potential of becoming embryos. Pluripotent stem cells have every

Stem Cells : What Are They? Many types of stem cells exist in the human body. All have the capacity to replicate, to self-renew; and they have the capacity to differentiate in order to produce specific body parts such as muscle cells,

putting this is to say that stem cells are pluripotent rather than totipotent . It is true that advanced technology might be able to render these cells effectively (if not actually) totipotent. Research undertaken in Canada in 1993 involving the

Totipotent Stem Cells Stem cells which are capable of forming every type of body cell. Each totipotent cell could replicate and differentiate and become a human being. All cells within the early embryo are totipotent up until the

Human Embryonic Stem Cells The study of human stem cells has barely begun and what is known is summarized in this section. The vast majority of experimental data discussed here are the results of experiments in mice. ES cells from

can contribute. Totipotent stem cells are cells that can give rise to a fully functional organism as well as to every cell type of the body. Pluripotent stem cells are capable of giving rise to virtually any tissue type, but not

funding to support stem cell research wish to avoid the problems associated with restrictions on embryo research; so they exempt stem cells through definition. If stem cells are pluripotent and not totipotent , then they escape

this the case? Is it because totipotent cells have a genetic potential lacking in pluripotent cells? No. What distinguishes them is that totipotent cells have access to a placenta making them available for implantation; whereas pluripotent stem

the source for pluripotent cells. Then we would experience a shift in ethical ground tantamount to an earthquake. Initially and naively, we could breathe a sigh of relief. If laboratory scientists are no longer tempted to harvest stem cells

could generate enough stem cells in culture to preclude constant demand for more and more tissue. In sum, stem cell research as presently understood should have a negligible impact on IVF or abortion practices. The Ethics Advisory Board