stem cells

• Stem cells


  Cells that can divide by mitosis to form more cells and can differentiate into specialized cells
• Stem cells

  • Can divide by mitosis to form more cells
  • Can differentiate into specialized cells
• How human life starts

  1. Sperm cell fertilizes egg cell

  2. Forms zygote

  3. Zygote divides by mitosis repeatedly

  4. Forms embryo

  5. Embryonic stem cells can differentiate into any cell type

  6. Cells continue to divide and differentiate

  7. Leads to baby after 9 months
• Embryonic stem cells


  Stem cells found in the embryo that can differentiate into any cell type
• What can adult stem cells differentiate to?

  Can only differentiate into a narrow range of cell types
• Adult stem cells

  • Stem cells in bone marrow that can differentiate into blood cells
• Plant stem cells

  Stem cells found in meristematic tissues in plants that can differentiate into all the cells and tissues the plant needs
• Plant stem cells persist for the plant's entire life, unlike embryonic stem cells which disappear by the time we're fully developed
• Adult stem cells can only differentiate into different types of blood cells, e.g. white blood cells, red blood cells and platelets. 
• Where in the body are adult stem cells found?

  Bone Marrow
• What do we call the plant tissues that are continually growing and that contain stem cells?

  Meristems
• Which two parts of the plant contain meristem tissue?

  Tips of the roots

  Tips of the shoots
• Meristems and cloning


  They can be used to make clones of the plant- this may be necessary if the parent plant has certain desirable features (such as disease resistance), for research or to save a rare plant from extinction.
• Therapeutic Cloning


  An embryo is produced with the same genes as the

  patient.

  • The embryo produced could then be harvested to obtain the embryonic stem cells.
  • These could be grown into any cells the patient needed, such as new tissues or organs.
  • The advantage is that they would not be rejected as they would have the same genetic makeup as the individual.
• What are adult stem cells used for?

  They are used to replace dying cells and damaged tissues.