CH6 the cell cycle Flashcards
What is the cell cycle
A highly ordered sequence of events that results in the division of a cell and the formation of two identical daughter cells
What is interphase
long periods of growth and normal working where cell carries out its major functions
What occurs during interphase
- DNA replicated and checked for errors in nucleus
- protein synthesis occurs in cytoplasm
- mitochondria and chloroplasts grow and divide
- normal metabolic processes of cell
What happens during G1
- proteins from which organelles are synthesised are produced
- organelles replicate
- cell increases in size
What happens during S
DNA replicated in nucleus
What happens during G2
- cell continues to grow in size
- energy stores increased
- duplicated DNA is checked for errors
What are the two stages of mitotic phase
- mitosis
- cytokinesis
What is G0
When cell leaves the cycle either permanently or temporarily
Why may a cell enter G0
- differentiation
- DNA damaged
How is the cell cycle controlled
By checkpoints which ensure that processes at each phase of the cycle has been accurately completed before progressing
What occurs at the G1 checkpoint
If cell satisfies requirements, DNA replication begins and if not, enters G0
What occurs at the G2 checkpoint
- DNA must have been replicated without error
- if passed, mitosis able to start
What occurs at spindle assembly checkpoint
Point where chromosomes should all be attached to spindles
