BIO - stem cells

• embryonic stem cells can turn into any type of cell - they are totipotent.
• differentiation is the process by a which a cell changes to become specialised for a particular job.
• stem cells are found in early human embryos.
• all the different types of cells found in a human being have to come from those few cells in the early embryo.
• adults also have stem cells, but they are found in certain places such as bone marrow.
• unlike embryonic stem cells, adult stem cells can't turn into any type of cell, they can only differentiate into certain cell types.
• stem cells from embryos and bone marrow can be grown in a lab to produce clones and made to differentiate into specialised cells to use in medical research.
• adult stem cells are used to cure diseases and replace damaged cells in the body
• embryonic stem cells can be used to replace damaged cells in the body and can be used to treat diseases
• in therapeutic cloning, an embryo could be made to have the same genetic information as the patient - therefore the stem cells would not be rejected by the patient's body.
• there are some risks involved in using stem cells such as: the stem cells grown in the lab may become contaminated with a virus which could be passed on to the patient.
• some people believe that life begins at conception, therefore they feel that human embryos shouldn't be used fro research as each one is a potential life.
• some people think that curing patients who already exist and who are suffering is more important than the rights of embryos.
• one arguement that defends the use of embryonic stem cells, is that the embryos used in research are usually unwanted ones from fertility clinics. therefore, if they weren't used for research, they would be destroyed.
• in plants, stem cells are found in meristems and are able to differentiate into any type of cell.
• the main meristems of the plant are close to the tip of the shoot and the tip of the roots.
• stem cells from plants can be used to produce clones of whole plant quickly and cheaply.
• stem cells in plants can be used to grow more plants of rare species - to prevent them from being wiped out).
• stem cells can be used to grow crops of identical plants that have desired features for farmers, for example, disease resistant.