Bone marrow stem cell, coloured scanning electron micrograph (SEM). This cell is known as a multipotential stem cell because it can form the precursors to every type of blood cell. During blood cell development the multipotential stem cell develops by a process known as haemopoiesis into either red blood cells (erythrocytes), or one of three types of white blood cell (granulocytes, lymphocytes or monocytes). Blood cells have short lifespans and are therefore constantly produced by the bone marrow.
Credit: SCIENCE PHOTO LIBRARY