5.8 Stem Cells

These are the precursors of all followed cell types e.g. blood stem cells removed from the umbilical cords of new born babies. The blood stem cells, produce by mitosis all the types of blood cells including T and B-lymphocytes.  It also produces by mitosis more stem cells this ensuring and inexhaustible supply of cells. The blood stem cells are present in everyone’s bone marrow.  Umbilical cord blood has a much higher proportion of stem cells in it.