cancer and cell cycle Flashcards
name the 3 main checkpoints
G1 => S
G2 => Mitosis
Metaphase => Anaphase
G1 => S
is the cell big enough?
G2 => Mitosis
is DNA replicated?
Metaphase => Anaphase
are chromosomes aligned?
at each checkpoint, ______ acts as “stop signs”
specialized proteins
name 4 reasons cell division will not occur
cells of that type are not required
not enough nutrients for cell growth
DNA has not replicated
DNA is damaged
cell division is needed to replace _______ and _______ cells
damaged / worn out
when cells leave at the first checkpoint, what cycle do they enter?
non dividing stage
how many cells die in the human body per minute?
3 billion
what are 2 types of cell death?
apoptosis
necrosis
why do cells leave the cell cycle?
it’s time to die
what is apoptosis?
programmed cell death
what kills the cell (apoptosis)?
“suicide genes”
cells can only divide a certain number of times until they _________
receive instructions to die
what is a major purpose of apoptosis?
to remove cells that have lost their ability to function correctly
what is necrosis?
cell death due to unexpected and accidental cell damage
what are some reasons cells might be damaged beyond repair?
toxic chemicals (radiation, toxins) physical events (trauma, lack of oxygen due to blocked blood flow)
what happens when a cell ignores the “stop signs”?
they don’t leave the cell cycle to die, but continue to grow and divide repeatedly and excessively to create a lump of abnormal cells
what is the lump of abnormal cells called?
a tumour
what happens when a tumour is further mutated?
it can become cancerous