6.5 Stem Cells
First review @November 13, 2023
Practise Q's Done
Second review @November 17, 2023
the process of a cell becoming specialised is differentiation— this allows the cell to
carry out specific functions within an organism
differentiation involves the expression of a select few genes within a cell
Stem Cells
all cells begin as undifferentiated cells— these are cells that originate from cell
division, this can be either mitosis or meiosis
stem cells are not adapted to carry out any specific functions and have the potential to
differentiate into different specialised cells within an organism
stem cells are able to undergo cell division until they become senescent (reach their max
cell divisions) and then enter the G0 phase
activity of stem cells must be closely monitored— if they divide too slowly, tissue cells
won’t be replaced fast enough and if they divide too quickly and uncontrollably then a
cancerous tumour may develop
Stem cell potency:
potency— a cells ability to differentiate into different cell types
the greater the number of cells it can differentiate into, the greater the potency
types of potency:
totipotent— can differentiate into any type of cell including embryonic tissue cells,
only totipotent until embryonic tissue cells are formed
pluripotent— can differentiate into any cell except embryonic tissue cells, cannot
form a new organism like totipotent cells
multipotent— can only differentiate into cells of the same type tissue, e.g.
haematopoietic stem cells give rise to many types of blood cells and are found in
bone marrow
6.5 Stem Cells 1
First review @November 13, 2023
Practise Q's Done
Second review @November 17, 2023
the process of a cell becoming specialised is differentiation— this allows the cell to
carry out specific functions within an organism
differentiation involves the expression of a select few genes within a cell
Stem Cells
all cells begin as undifferentiated cells— these are cells that originate from cell
division, this can be either mitosis or meiosis
stem cells are not adapted to carry out any specific functions and have the potential to
differentiate into different specialised cells within an organism
stem cells are able to undergo cell division until they become senescent (reach their max
cell divisions) and then enter the G0 phase
activity of stem cells must be closely monitored— if they divide too slowly, tissue cells
won’t be replaced fast enough and if they divide too quickly and uncontrollably then a
cancerous tumour may develop
Stem cell potency:
potency— a cells ability to differentiate into different cell types
the greater the number of cells it can differentiate into, the greater the potency
types of potency:
totipotent— can differentiate into any type of cell including embryonic tissue cells,
only totipotent until embryonic tissue cells are formed
pluripotent— can differentiate into any cell except embryonic tissue cells, cannot
form a new organism like totipotent cells
multipotent— can only differentiate into cells of the same type tissue, e.g.
haematopoietic stem cells give rise to many types of blood cells and are found in
bone marrow
6.5 Stem Cells 1
