Differentiation and stem cells

• Cell differentiation is the process by which a cell changes to become specialised for its function
• Stem cells:

  • undifferentiated cells
  • can divide to produce many more undifferentiated cells
  • can differentiate into different types of cells
• Embryonic stem cells are found in the early stages of the embryo, they can differentiate into any type of cell
• Adult stem cells are found in different tissues including the bone marow, they cannot specialise into any type of cell, only certain ones, including red and white blood cells
• Medicine uses adult stem cells to cure disease, this is called stem cell therapy
• Stem cells are transferred from the bone marrow of a healthy person to a patient and can replace faulty blood cells in the patient who recieves 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, nerve cells for people paralysed by spinal injuries, etc..
• Embryonic stem cells are obtained from unused embryos from fertility clinics
• Many people object morally to using embryonic stem cells for medical purposes, since each one is a potential human life, even though the embryos would simply be destroyed otherwise
• There are also risks involved in using stem cells in medicine. For example, stem cells grown in a lab may be contaminated by a virus which could be passed on to the patient
• In plants, stem cells are found in meristems (parts of the plant where growth occurs)
• Throughout the plant's entire life, cells in the meristem tissues can differentiate into any type of cell
• These stem cells can be used to produce clones of whole plants quickly and cheaply
• Stem cells from plants can be used to grow more plants of rare species
• Stem cells can be used to grow crops of identical plants that have desired features for farmers, for example disease resistance