8A Stem Cells Flashcards
Define stem cells
undifferentiated cells that are able to differentiate into different types of specialised cells
Where are embryonic stem cells founds
in the embryo
define totipotent cells
cells than can differentiate into any type of body cell
Where are totipotent cells found
in mammals in the first few divisions of the embryo
Define pluripotent cells
cells that are able to diffrent into many but not all cells eg germ cells
Define multipotent cells
cells that are able to differentiate into a few different types of cells eg red or white blood cells
Define unipotent stem cells
cells that are able to differentiate into only one type of cell eg epidermal skin cells
How do stem cells become specialised
when different genes are expressed in the right conditions
What is a cardiomyocyte
a heart muscle cell
What are cardiomyocytes made from
unipotent stem cells
What are stem cells used to treat
Bone marrow transplants to treat leukaemia and lymphoma
Sickle cell anaemia and severe combined immunodeficiency
Spinal cord injuries
Heart disease and damage caused by heart attacks
Bladder conditions
Respiratory diseases
Organ transplants
Stem cell benefits
Could save many lives
Could improve the quality of lives
Adult stem cell benefits
Obtained in a simple operation with little risk
Adult stem cell disadvantages
Can cause discomfort
They aren’t as flexible as embryonic stem cells
Embryonic stem cell advantages
they are pluripotent
Embryonic stem cell disadvantages
could be unethical
How do induced pluripotent cells work
by reprogramming specialised adult body cells to become pluripotent these are made to express a series of transcription factors
What are transcription factors
proteins that control whether or not a gene is transcribed
Ethical issues surrounding embryonic stem cells
people believe that you could be destroying a potential foetus
There are fewer objections to stem cells being obtained from egg cells that have not been fertilised but have been artificially activated as these would not survive in a womb
People believe that adult stem cells should be used as these do not destroy potential lives
Why should induced pluripotent stem cells be used
They could be made from a patients own cells so there is less chance of the cells being rejected by the body
