What Are Stem Cells?
Stem Cell: An undifferentiated cell that has the capacity to divide indefinitely by mitosis and to differentiate into one or more specialized cell types.
Stem cells are fundamental to life , they drive growth and development in embryos, and they maintain and repair tissues throughout an organism's lifespan. Not all stem cells are equal, however. Their potency , the range of cell types they can give rise to , varies significantly.
Biologists classify stem cells into three main categories based on this potency:
- Totipotent , can become any cell type, including extra-embryonic tissues
- Pluripotent , can become any cell type of the body, but not extra-embryonic tissues
- Multipotent , can become a limited range of related cell types within a specific tissue
Understanding the differences between these categories is essential for both developmental biology and the growing field of regenerative medicine.
The prefixes help you remember the hierarchy: toti- (Latin for "all/whole"), pluri- (Latin for "many"), multi- (Latin for "several"). Potency decreases from totipotent → pluripotent → multipotent.