stem cells

• stem cells found in early human embroys can turn into any type of cell while stem cells found in adults (e.g from bone marrow) are limited to certain cells (e.g blood cells).

  stem cells can be grown in a lab to produce clones made to diffrentiate into specialised cells to be used in medicine or research.
• adult and embryonic stem cells can be used to cure disease (e.g healthy adult stem cells transplanted to replace faulty blood cells, or embryonic nerve cells to help people paralysed by spinal injurys).

  in theraputic cloning an embryo could be made to have the same genetic information as the patient so the stem cells are not rejected by the patients body, however there are risks of using stem cells (e.g cells grown in a lab could become contaminated by a virus).
• some people think using human embryos for research is immoral because they believe it is wrong to destroy human life, others think curing existing patients is more important.
• in plants stem cells are found in meristems (where growth occurs) and never loose the ability to diffrentiate, these stem cells can be used to clone plants (prevent extinction, grow plants with wanted features e.g disease resistance).