stem cells and cellular differentiation

• cellular differentiation is the process by which a cell becomes specialized to perform a specific function
• stem cells are cells that can differentiate into many different cell types
• in stem cells, each daughter cell can develop into a different type of cell depending on which parts of its DNA are switched on
• the 2 types of stem cells are:

  • embryonic
  • tissue (adult stem cells)
• embryonic stem cells can differentiate into any kind of cell
• tissue (adult stem cells) exist within specialized tissue and are only able to differentiate into certain types of cells (ex. stem cells in bone marrow can differentiate into white blood cells, red blood cells, or platelets)
• blood in the umbilical cord immediately following birth is a rich source of stem cells; they can develop into any kind of blood cell
• cord blood and bone marrow stem cells have both been used to treat diseases (leukemia)
• donor blood stem cells are injected into the patient's blood, grow in the patient's bone marrow and produce healthy blood cells
• in animals, regeneration refers to the ability of a tissue to repair itself
• starfish, flatworms, and salamanders can often replace large portions of their body