stems cells Flashcards
what is a stem cell
- Undifferentiated cells
- continually divide
- become specialised
3 types of stem cells
- Totipotent: devolve into any type of cell
- pluripotent: can develop into any cell type excluding placenta and embryo
- multipotent: can only develop into a few different types of cells
What happens to totipotent cells during embryonic development
Certain parts of the DNA are selectively translated so that only some genes are ‘switched on’ in order for cells to differentiate into a specific type and form the tissues that make up the foetus
feature of pluripotent stem cells
- divide unlimited
- used to repair or replaced damaged tissues
unipotent stem cell
- develop into 1 type of cell
- eg cardiomyocytes (heart cells)
what stem cells are found in embryos
totipotent and pluripotent
what stem cells are found in mature animals
multipotent and unipotent
uses of stem cells
- medical therapies eg bone marrow transplants
- drug testing on artificially grown tissues
- research
sources of stem cells
pluripotent = embryos up to 16 days after fertilisation
multipotent = umbilical cord blood /placenta
adult stem cells = bone marrow
how are induced pluripotent stem cells created
- created from adult unipotent cells and returned to state of pluripotency
- genes that were switched off to make them specialised must be switched back on
- using TF
why use IPS
don’t cause destruction the embryo
why are IPS good
- self renewal properties
- divide indefinitely
