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Types of stem cells🧐
Stem cells are undifferentiated cells.
EMBRYONIC - can differentiate into every type of cell in your body
ADULT STEM CELLS - they are only found in certain places (eg. the bone marrow), they aren't as versatile as emb. cells as they can only produce several types of specalised cell.
MERISTEMS (plants only) -
- only cell in plants that divide by mitosis.
- found in the parts of a plant that are growing (eg. tip of roots and shoots).
- produce unspecialsed cells that are able to divide and form any cell type.
- can divide and differentiate for as long as the plant lives.
- unspecialised cells --------> specialised tissues
Stem cells in medicine🤒
In I/GCSE Biology, you may be asked to weigh the benefits and risks of using stem cells
BENEFITS:
- Already used to cure some diseases (eg. sickle cell aneamia can sometimes be cure by a bone marrow transplant)
- Emb. cells can be extracted and grown. Under certain conditions they can be stimulated to differentiate into specialised cells
- It may be possible to create specialised cells from stem cells to replace those which have been damaged.
RISKS:
- Rejection - if transplanted cells aren't grown using the patient's own stem cells, the patients body may recognise the cells as foreign and trigger an immune response. Although drugs can be taken to supress this response, it makes the patient suspectable to disease and illness
- Tumour development - stem cells divide quickly, if the scientists are unable to control the rate of division, a tumour may develop
- Disease transmission - viruses are inside cells, if they go undetected and stem cells are then transplanted, the virus may be passed on, making the recipient even sicker.
Drafted by Catrina (Biology)