The cell cycle 2.1.6 (a,b) Flashcards
what are the three phases of the cell cycle?
interphase
mitotic phase
cytokenesis
what happens during interphase?
DNA is replicated
protein synthesis
mitochondria and chloroplasts grow and divide
what are the three stages of interphase?
G1
S phase
G2
what happens during G1?
proteins synthesise organelles which then replicate
the cell grows in size
what happens during S phase?
DNA is replicated in the nucleus
what happens during G2?
cell continues to grow in size
energy stores are increased
replicated DNA is checked for errors
what happens during the mitotic phase?
mitosis- the nucleus divides
cytokinesis- the cytoplasm divides
what happens during G0?
when the cell leaves the cell cycle
why may a cell enter G0?
- if the cell becomes specialised by differentiating which means it cannot divide
- if the DNA is damaged which makes the cell no longer viable
how is the cell cycle controlled?
through checkpoints
what are the three checkpoints in the cell cycle?
G1 checkpoint
G2 checkpoint
spindle assembly checkpoint
what is checked at the G1 checkpoint?
checks the DNA for damage before it replicates
ensures the DNA has the right amount of chemicals
what is checked at the G2 checkpoint?
checks the DNA has replicated without error before cell division occurs
what is checked at the spindle assembly checkpoint?
checks whether the chromosomes had been attached to the spindles
