There are cells that are not specialised, and thus can use all of their DNA:
- Embryonic stem cells
- Adult stem cells: in the small intestine, skin and bone marrow
- Most plant cells
Mature mammals also have multipotent cells which are able to specialise, but only into certain cells.
A cell from a plant can be grown in vitro, this means outside a living organism, in a nutrient medium with chemical stimuli, into a new plant or organ because of their totipotency.
Totipotent and multipotent cells can be used to create tissue to repair damage caused by disease or other medical issues by using growth factors to make them differentiate, for example red blood cells could be grown to treat leukaemia or beta cells could be grown to help someone with diabetes. There are different growth factors which are have different effects depending on concentrations and combinations.
Embryonic stem cells have be found more useful as they are easier to manipulate, however, there are ethical issues with using embryonic stem cells in this way:
- Some people consider embryos to be living things
- Research in that area could lead to cloning or people choosing the genetics of their babies
- Embryos are just cells and not life
- There are laws prohibiting cloning and 'designer babies' in the UK so that is not a problem]
- It is wrong to continue to let people suffer when they could be treated as a result of stem cells