Mitosis Flashcards
Checkpoints
“stop” and go-ahead” signals regulate cycle
3 checkpoints
G1
G2
M
G1 checkpoint
withought the go-ahead; cell goes into G0 sort of like cellular limbo. Functionally, but not dividing, not growing.
M checkpoint
kinetochore attachment on all chromosomes to mitotic spindle fibers gives the go-ahead to move from metaphase to anaphase
M checkpoint
If the microtubules spindles do not attach properly, cell division dosent occur –> can signal that something is wrong
apoptosis
cellular programmed death
proliferation
rapid growth and division
anchorage dependency
cells require a surface for division
Density-dependent inhibition
cells from a single layer, cells divide to fill a gap then stop
cancer
cells divide withought listening to typical stop signals; uncontrolled cellular division
Benign
dosent spread to other tissues
malignant
dangerous, spreads to other tissues
metastasis
spread to distant parts of body
Henrietta Lacks
she had cervical cancer, during her tumor removal scientists took samples without her consent.
her cells turned out to be immortal - good for growing in a lab
Her cells are called HeLa cells and have had an immeasurable impact on cancer research
PDGF
platelet-derived growth factor: made by platelets (cells in bloodstream)
when other cells pick up this growth factor - triggers signal transduction and provides a ‘go-ahead’ signal
