1.5 Protein control of cell division

Question 1

What are the 4 stages of the cell cycle.

Answer 1

Mitosis, G1, Synthesis and G2.

Question 2

Where are the checkpoints, and their names?

Answer 2

G1 Checkpoint, G2 checkpoint and the spindle assembly checkpoint (M).

Question 3

Describe the G1 checkpoint.

Answer 3

Cell growth and proliferation in the G1 stage creates a build up of cyclin-dependent kinase, which phosphorylates and inhibits retinoblastoma. Insufficient phosphorylation of retinoblastoma prevents progression of the cell cycle. Cells not sufficiently phosphorylated are put into G0, or quiescence.

Question 4

Describe the G2 checkpoint.

Answer 4

G2 checkpoints prevents the progression of damaged cells to the mitosis stage.

Question 5

What occurs at the S stage of the cell cycle?

Answer 5

DNA replication.

Question 6

What is triggered if the cell is damaged.

Answer 6

p53, which either repairs the damaged cell, or triggers apoptosis.

Question 7

What are the 4 stages of mitosis?

Answer 7

Prophase, metaphase, anaphase and telophase.