Stem Cells
- Stem cells are undifferentiated cells that are able to express all of their genes and divide by mitosis.
- During development, the stem cells undergo cell differentiation. This is the process by which cells become specialised for different functions.
- Fully developed cells are unable to divide by mitosis
Stem Cell | Ability |
Totipotent | Can divide and differentiate into any type of cell. |
Pluripotent | Can self-renew and differentiate into any type of cell except the cells that make up the placenta. |
Multipotent | Can only differentiate and divide into a limited number of cell types |
Unipotent | Can only differentiate into a single type of cell e.g. cardiomyoblasts can only differentiate into cardiomyocytes. |
- Totipotent stem cells are only present in mammals in the first few cell divisions of an embryo. During development, totipotent cells become specialised by expressing different genes and producing different proteins.
- Induced pluripotent stem cells are unipotent stem cells that have been reprogrammed to become pluripotent by using protein transcription factors to express genes associated with pluripotency.
- Pluripotent stem cells can be used to replace cells and treat human disorders like leukaemia and diabetes