Stem Cells

• Stem cell research has exciting possibilities, but it is also pretty controversial.
• Embryonic stem cells

  Can turn into any type of cell
• Undifferentiated cells


  Can divide to produce more stem cells
• Stem cells

  Can differentiate into different types of cell, depending on what instructions they're given
• Stem cells are found in early human embryos
• Adults also have stem cells
• Adult stem cells

  Can't turn into any cell type at all- only certain ones, such as blood cells
• Stem cells from embryos and bone marrow can be grown in a lab
• • Undifferentiated cells, called stem cells, can divide to produce more stem cells. They can differentiate into different types of cell, depending on what instructions they're given.
• • Stem cells are found in early human embryos. These can differentiate into any type of cell.
  • Adults also have stem cells, but they're only found in certain places, like bone marrow.
  • Unlike embryonic stem cells, adult cells can't turn into any cell type at all- only certain ones, such as blood cells.
  • Stem cells from embryos and bone marrow can be grown in a lab to produce clones and be made to differentiate into specialised to use in medicine or research.
• Stem cells may be able to cure many diseases
• • Medicine already uses adult stem cells to cure disease. For example, stem cells transferred from the bone marrow of a healthy person can replace faulty blood cells in the patient who receives them.
• • Embryonic stem cells could also be used to replace faulty cells in sick people- you could make insulin-producing cells for people with diabetes, or nerve cells for paralysed people.
• • In a type of cloning, called therapeutic cloning, an embryo could made to have the same genetic information as the patient. This means that the stem cells produced from it would also contain the same genes and wouldn't be rejected by the patient's body if used to replace faulty cells.
• • There are risks in using stem cells in medicine. For example, stem cells grown in the lab may become contaminated with a virus that could be passes on to the patient and make them sicker.
• Some people are against stem cell research.

  • They feel human embryos shouldn't be used for experiments since each one is potential human life.
  • They campaign for the rights of embryos and feel that scientists should concentrate more on finding and developing other sources of stem cells, so people could be helped without using embryos.
  • In some countries stem cell research is banned, but it's allowed in the UK as long as it follows strict guidelines.
• Some people argue the embryos will be destroyed either way.

  • They think curing patients who already exist and who are suffering is more important than the rights of embryos.
  • They argue that the embryos were probably unwanted anyway, so it's better they are used for research.
• Stem cells can produce identical plants

  • In plants, stem cells are found in the meristems (where growth occurs)
  • Throughout the plant's entire life, cells in the meristem tissues can differentiate into any type of plant cell.
  • These stem cells can be used to produce clones (identical copies) of whole plants quickly and cheaply.
  • They can be used to grow more plants of rare species (to prevent them being wiped out)
  • Stem cells can also be used to grow crops of identical plants that have desired features for farmers, like disease resistance.
• Some species of orchid are endangered in the UK. Many can be successfully reproduced using stem cells.
• It may be possible to 'reprogramme' differentiated adult cells back into an undifferentiated stage.