Stem Cells

• A stem cell is an undifferentiated cell of an organism which is capable of giving rise to many more cells of the dame type, and from which certain other cells can arise from differentiation
• Embryonic stem cells are found in early embryos and are completely undifferentiated. This means that they can be used to turn into any type of cell.

  Embryonic stem cells can be cloned and made into most types of cells.

  Environmental factors can be used to influence their differentiation into almost any kind of cell
• Adult stem cells, found in bone marrow, differentiate into fewer cell types than stem cells in embryos. They are used to replace dying cells and damaged tissues
• Cells of the meristem can differentiate to produce all types of plant cells at any time during the life of the plant.

  The main meristems are close to the tip of the shoot, and the tip of the root.

  in a growing shoot, new cells are produced continuously near the tip
• Stem cells from human embryos can be clones and made to differentiate into most different types of human cells
• Stem cells from adult bone marrow can form many types go cells including blood cells
• Meristem tissue in plans can differentiate into any type of plant cell throughout the life of the plant
• Treatment with stem cells may be able to help with conditions such as diabetes and paralysis
• In therapeutic cloning an embryo is produces with the same genes as the patient
• Stem cells form the embryo are not rejected by the patients body so they may be used for medical treatment
• The use of stem cells has potential risks, such as transfer of viral infection, and some people have religious or ethical objections
• Stem cells from meristems in plants can be used to produce clones of plants quickly and economically.

  • Rare species can be cloned to protect from extinction
  • Crop plants with special features such as disease resistance can be cloned to produce large numbers of identical plants for farmers