The cell cycle

Question 1

Interphase

Answer 1

1. G1 - 1st growth phase where cell grows and new organelles and proteins are made.
2. S - Synthesis phase where DNA is replicated in the nucleus.
3. G2 - 2nd growth phase where cell keeps growing and proteins needed for cell division are made.

Question 2

Mitosis

Answer 2

The mitotic phase is the period of cell division. Cell division involves 2 stages: mitosis (nucleus divides) and cytokinesis (cytoplasm divides and 2 cells are produces).

Question 3

G0

Answer 3

When cell leaves the cycle either temporarily or permanently.

Differentiation: cell becomes specialised to carry out particular function and cannot divide.

DNA of cell may be damaged and it is no longer viable: Damaged cell can no longer divide.

Question 4

What are checkpoints?

Answer 4

Checkpoints are control mechanisms of the cell cycle and it regulates them.
They monitor and verify whether the processes at each phase of the cell cycle have been accurately completed before the cell is allowed to progress into the next phase.

Question 5

Checkpoints

Answer 5

G1 Checkpoint: Cell checks that the chemicals needed for replication are present and for any damage to the DNA before S-phase.

G2 Checkpoint: Checks whether all DNA has been replicated w/o damage. Then cell can enter mitosis.

Metaphase checkpoint: Checks if chromosomes are attached to spindles and have aligned.