They are functionally to reproduce themselves throughout the life span of an animal and have the ability to produce at least one type and often several types of specialized cells that make up the body of an animal.
Stem cells undergoes linage commitment and differentiation, resulting in differentiated progenitors, precursor cells, and ultimately, terminally differentiated cells.
Differentiation is defined of cell type specific morphological, phenotypic, and functional features.
Stem cells are named primarily in two ways:
*by the age of the originating organisms, hence, embryonal stem (ES) and adult stem cells
*by the chief type of cell produced by the stem cell, such as germ stem (GS) cells which give rise to sex cells of the germ line and hematopoietic cells stem cells (HSC) which give rise to all adult blood cell lineages.
What is stem cells?