Stem cells

• A stem cell is an undifferentiated cell which can give rise to more cells of the same type and can differentiate to form other types of cells
• The stem cells in bone marrow differentiate to form cells found in our blood

  
• Treating Leukaemia (Cancer of the bone marrow) via Bone marrow transplants:

  1. Patient's existing bone marrow destroyed using radiation
  2. Transplant of bone marrow received via donor
  3. Stem cells divide and form new bone marrow
• In bone marrow transplants, the donor must be compatible otherwise white blood cells produced by the donated bone marrow could attack the patient's body
• The problems of bone marrow transplants include:

  1. The donor must be compatible
  2. Viruses being passed from the donor to the patient
• In therapeutic cloning, an embryo is produced with the same genes as the patient, meaning that stem cells can be transplanted into the patient from the embryo without being rejected by the patient's immune system and once inside the patient, stem cells can differentiate to replace cells that stopped working properly.
• Therapeutic cloning can be useful for a range of medical conditions such as diabetes or paralysis, however there are ethical and religious objections to the procedure.
• Cloning can be used to stop rare plants from going extinct, or producing cloned crop plants for farmers.
• Meristem tissue in plants can differentiate into any type of plant cell throughout the life of the plant. Stem cells from these meristems can be used to produce clones of plants quickly and economically