Stem Cell

'''Stem cells''' are undifferentiated cells found in most, if not all, multi-cellular organisms. A stem cell is a "blank-slate" cell that spawns more-specialized cells to form tissues and organs, and is also self-renewing. They are characterized by the ability to [[Self-Rejuvenation|regenerate and renew themselves]] and the ability to differentiate into other cells. Their daughter cells may differentiate into other cell types (such as blood cells,..) which can be used to regenerate and repair the body. Therefore they are the body building cells of multi-cellular organisms. [[Cancer_Stem_Cell|Cancer stem cells]] are cancer cells that possess characteristics associated with normal stem cells.

The most versatile stem cells, embryonic stem cells, are found in the early embryo formed by the fusion of sperm and egg at conception. They generate specialized generations of cells to create the body's entire array of tissues and organs. The body also maintains "pools" of "adult stem cells" that are slightly less versatile than those in the embryo, but which can manufacture replacement cells for specific organs when needed.

== Links ==

* Wikipedia Entry for [http://en.wikipedia.org/wiki/Stem_cell Stem Cell]