6.1 The cell cycle Flashcards
processes taking place during
interphase
G1, S and G2
what are the 5 stages of the cell cycle
G1, S and G2 mitosis and cytokinesis,
mitosis
nuclear division produces 2 identical cells
impotance of mitosis
- growth
- repair
- asexual reproduction
- replacment
whats the role of checkpoints in the cell cycle
control mechanisms that monitor, regulate and verify trigger the next stage
what occurs at G1in the cell cycle
‘growth phase’
- protein synthesis and organelles are replicated
- cell size increases
- G1 checkpoint: cell size nutrients dna damage growth factors
what is G0? when does it occur and why?
cell leaves the cell cycle temorarily or permanently if it fails its checks at G1 this can be due to
* differnetiation : cell becomes specialised and no longer able to divide and wont return
* damaged: DNA is damaged and no longer viable permanet arrest occurs most cells have a set no times before this occurs
* age: cell becomes senescant
what happens in the S phase
‘synthesis stage’ DNA is replicated
what happens in the G2 phase?
‘2nd growth phase’
- increases in size further
- increases in energy store
- Dna checked for errors while duplicating
- more protein synthesis
whats regulated at the G2 checkpoint?
- cell size
- dna damage
- dna replication
where does a cel go if fails G1 checkpoint
G0 senescant
the third checkpoint in the cell cycle is
spindle checkpoint during metaphase checks that the chromosones are attached to the spindle
M phase consists of both …….. and ……..
mitosis and cytokinesis
sister chromatids are bound at a
centromere
homologous pair of chromosomes overlap at
chiasmata
