stem cells

• describe stem cells

  undifferentiated cells that divide by mitosis to produce more undifferentiated cells and differentiate into different types of cells
• give types of animal stem cells

  embryonic and adult
• describe embryonic stem cells

  come from early human embryo to differentiate into most types of cells
• describe adult stem cells

  come from adult bone marrow and differentiate into certain types of cells (blood cells)
• give conditions treated by stem cells

  diabetes and paralysis
• give two medical uses of stem cells

  faulty cell replacement and therapeutic cloning
• describe process of faulty cell replacement

  1. extract embryonic stem cells
  2. stimulate differentiation
  3. replace faulty cells with specialised cell
• describe process of therapeutic cloning

  1. embryo produced with same genetic material as patient
  2. embryonic stem cells transplanted to patient
  3. embryonic stem cells differentiate inside patient
• give disadvantages of stem cell treatment

  limited supply of embryonic stem cells, risk of infection, risk of rejection and ethical objections
• give type of plant stem cell

  meristem
• describe meristem stem cell

  found in growing roots and shoots to differentiate into any type of plant cell
• give uses of meristem stem cells

  produce clones of desired plants for particular characteristic or prevent extinction