Stem cells

• What is a stem cell?


  An unspecialised cell which is capable of differentiating into other cell types and of self-renewal
• What is the function of stem cell in embryos?


  embryonic stem cells can replicate themselves and differentiate into other types of cells.

  may be able to treat conditions like paralysis and diabetes by dividing to replace damaged cells
• What is the function of stem cells in adult bone marrow?


  adult stem cells can differentiate into several cell types to replace dead or damaged tissues. bone marrow stem cells can form many different types of blood cells.
• What is the function of stem cells in plant meristems?


  Meristem stem cells retain ability to differentiate into any type of cell throughout their lifespan.
• What is therapeutic cloning?


  A cloning method where an embryo is produced with the same genetic makeup as the patient.

  the stem cells which originate from the embryo will not be rejected by the patient's immune system.
• What are the advantages of cloning plants using meristem stem cells?


  can prevents extinction of rare plants

  can produce large numbers of plant with a favourable characteristic

  can produce identical plants for research
• What are the issues with the use of embryonic stem cells?


  many embryonic stem cells are from abortions

  ethical/religious objections

  stem cell therapies are slow,expensive and difficult

  adult stem cells infected with virus can transfer to patient

  if not similar genetic makeup the immune system could have an response