B2.2 Growth and differentiation Flashcards
humans begin life as what
a fertilised egg cell
what does the fertilised egg cell undergo
mitosis
why does the fertilised egg cell undergo mitosis
to form an identical ball of ESCs
what happens to ESCs
differentiate to form many different types of cell required in the body
in animals differentiations happens when
at an early stage of development
cells are what to do a particular job
specialised
genes are switched ‘on’ or ‘off’ resulting in what
different sub-cellular structures to enable it to carry out a certain function
adult stem cells (ASCs) exist in some tissues to what
replace dead or damaged specialised cells that cannot divide by mitosis
ASCs are not what
differentiated (not specialised)
in plants, most plant cells have the ability to do what all through their lives
differentiate
undifferentiated cells form at active regions of where called what-plant
root and stem called meristems
what happens in the meristems
mitosis and later differentiation to take on specialised roles when they reach their final position in the plant
do plants differentiate permanently
no- if moved to another location, they an re-differentiate to become another type of cell
differentiation
the process by which cells become specialized to perform specific functions in an organism
stem cells
undifferentiated cell which can differentiate to form other types of cells
