Stem Cells

• Differentiation is the process by which a cell changes to become specialised for its job.
• Undifferentiated cells, called stem cells, can divide to produce lots more undifferentiated cells. They can differentiate into different types of cell, depending on what instructions they’re given.
• Stem cells are found in early human embryos. They're exciting to doctors and medical researchers because they have the potential to turn into any kind of cell at all.
• Adults have stem cells found in certain places like bone marrow. Unlike embryonic stem cells, they 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 (genetically identical cells) and made to differentiate into specialised cells to use in medicine or research.
• Medicine 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 can be used to replace faulty cells in sick people - you could make insulin producing cells for people with diabetes, nerve cells for people paralysed by spinal injuries, and so on.
• In a type of cloning called therapeutic cloning, an embryo could be made to have the same genetic information as the patient. This means that the stem cells produces from it would also contain the same genes and so wouldn’t be rejected by the patient‘s body if used to replace faulty cells.
• There are risks involved in using stem cells in medicine. For example, stem cells grown in the lab may be contaminated with a virus which could be passed on to the patient and so make them sicker.
• Some people are against stem cell research because they feel that human embryos shouldn’t be used for experiments since each one is a potential human life. However others think that curing existing patients who are suffering is more important than the rights of embryos. They argue that the embryos used in the research are usually unwanted ones from fertility clinics which if they weren’t used for research would probably just be destroyed.
• In some countries stem cell research is banned. It’s allowed in the UK as long as it follows strict guidelines.
• In plants, stem cells are found in the meristems (parts of the plant where growth occurs).
• Throughout a plants entire life, cells in its meristem tissues can differentiate into any type of plant cell.
• Stem cells found in plants meristems 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 from being wiped out) They can also be used to grow crops of identical plants that have desired features for farmers, for example, disease resistant.