6.1 Cell Cycle Flashcards
What are the two main phases of the cell cycle
Interphase and the mitotic phase
What is the interphase
Long periods of growth and normal working
What different processes happen to the cell during interphase
- DNA is replicated and checked for error
- Protein synthesis occurs
- Mitochondria grow and divide
- Chloroplasts grow and divide in plant and algal cell cytoplasm’s
- The normal metabolic processes of cells occur
What are the 3 stages of interphase
G1, S, and G2
What happens during the G1 phase
It is the first growth phase. Proteins from which organelles are synthesised are produced and organelles replicate. Also the cell increases in size
What happens during the S phase
The synthesis phase. DNA is replicated in the nucleus
What happens during the G2 phase
The second growth phase. The cell continues to increase in size, energy stores are increased and the duplicated DNA is checked for errors
What is the mitotic phase
The period of cell division
What are the two stages of cell division (mitotic phase)
Mitosis and Cytokineses
What happens during mitosis
The nucleus divides
What happens during cytokineses
The cytoplasm divides and two cells are produced
What is the G0 phase
The phase where the cell leaves the cycle
What are the possible reasons for a cell leaving the cell cycle
Differentiation, Damaged DNA and Age
What is differentiation and why does it cause a cell to leave the cell cycle
It is a cell that becomes specialised to carry out a particular function. These types of cells are unable to divide so leave the cell cycle
Why does a damaged cell leave the cell cycle
A damaged cell can no longer divide and therefore enters a period of permanent cell arrest (G0)
What are checkpoints in the cell cycle
The control mechanisms of the cell cycle that monitor and verify whether each process has been accurately completed
What are the 3 checkpoints in the cell cycle
G1, G2 and spindle assembly (metaphase checkpoint)
Where is the G1 checkpoint
At the end of the G1 phase, just before the S phase
What does the G1 checkpoint check
- Cell size
- Nutrients
- Growth factors
- DNA damage
Where is the G2 checkpoint
At the end of the G” phase, beofre the start of the mitotic phase
What does the G2 checkpoint check for
- Cell size
- DNA replication
- DNA damage
Where is the spindle assembly checkpoint
At the point in mitosis where all the chromosomes should be attached to spindles
What does the spindle assembly checkpoint check for
Chromosome attachment to the spindle
