Can divide without limit. Stem cells that can give rise to only to one type of cell are called unipotent and stem cells that can give rise to many types of cells are called pluripotent . Epidermal stem cells are found in the basal layer, and are the only cells that can undergo mitosis. These cells will differentiate into keratinocytes which form the multilayered epidermis. Pluripotent stem cells differentiate into blood cells or hemopoietic cells.
All blood cells have limited life spans and are produced throughout the life of an animal.
They are generated from stem cells in bone marrow.