Stem Cell

• Stem cells

  Undifferentiated cells that can give rise to more cells of the same type and can differentiate to form other cell types
• to form a human a sperm meets with an ovum that will undergo mitosis forming an embryo then the embryo will differentiate to multiple specialised and normal body cells forming a human body and the cells in the embryo are the embryonic stem cells
• stem cells can be found in adult organisms such as bone marrow
• unlike embryonic stem cells, adult stem cells cant differentiate into any type of cells
• stem cells in the bone marrow differentiate to red blood cells, white blood cells, platelets
• stem cells are useful in medicine such as a bone marrow transplant for someone with leukaemia
• leukaemia is a bone marrow cancer
• how stem cells treat leukaemia

  the patients existing bone marrow is destroyed using radiation

  they patient receives a transplant from a bone marrow donor

  the stem cells in the bone marrow now divide and form a new bone marrow, the also differentiate and form blood cells
• problems with bone marrow transplant

  • the patient has to be compatible with the other patient or else the donor's white blood cells could attack the patients body.
  • or the patient theres risk of viruses being passed from the donor
• stem cells can also be used to therapeutic

  cloning
• therapeutic cloning is when an embryo is produced with the same genes of the patient so stem cells can be transplanted into the embryo without being rejected by the patients immune system. Then the stem cells can differentiate to replace cells that weren't working correctly
• therapeutic cloning is useful for diabetes or paralysis
• there are religious or ethical arguments to therapeutic cloning
• roots and buds contain meristem tissues that are stem cells that can differentiate into any other cell type at any moment in their life
• meristem tissue can be used to produce clones of a plant quickly and cheaply
• cloning plants can be useful for

  mass producing a rare plant to stop it going extinct

  mass producing crop plants that are resistant to a disease for farmers