6.1 Cell Cycle

Question 1

What are the two main phases of the cell cycle

Answer 1

Interphase and the mitotic phase

Question 2

What is the interphase

Answer 2

Long periods of growth and normal working

Question 3

What different processes happen to the cell during interphase

Answer 3

• 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

Question 4

What are the 3 stages of interphase

Answer 4

G1, S, and G2

Question 5

What happens during the G1 phase

Answer 5

It is the first growth phase. Proteins from which organelles are synthesised are produced and organelles replicate. Also the cell increases in size

Question 6

What happens during the S phase

Answer 6

The synthesis phase. DNA is replicated in the nucleus

Question 7

What happens during the G2 phase

Answer 7

The second growth phase. The cell continues to increase in size, energy stores are increased and the duplicated DNA is checked for errors

Question 8

What is the mitotic phase

Answer 8

The period of cell division

Question 9

What are the two stages of cell division (mitotic phase)

Answer 9

Mitosis and Cytokineses

Question 10

What happens during mitosis

Answer 10

The nucleus divides

Question 11

What happens during cytokineses

Answer 11

The cytoplasm divides and two cells are produced

Question 12

What is the G0 phase

Answer 12

The phase where the cell leaves the cycle

Question 13

What are the possible reasons for a cell leaving the cell cycle

Answer 13

Differentiation, Damaged DNA and Age

Question 14

What is differentiation and why does it cause a cell to leave the cell cycle

Answer 14

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

Question 15

Why does a damaged cell leave the cell cycle

Answer 15

A damaged cell can no longer divide and therefore enters a period of permanent cell arrest (G0)

Question 16

What are checkpoints in the cell cycle

Answer 16

The control mechanisms of the cell cycle that monitor and verify whether each process has been accurately completed

Question 17

What are the 3 checkpoints in the cell cycle

Answer 17

G1, G2 and spindle assembly (metaphase checkpoint)

Question 18

Where is the G1 checkpoint

Answer 18

At the end of the G1 phase, just before the S phase

Question 19

What does the G1 checkpoint check

Answer 19

• Cell size
• Nutrients
• Growth factors
• DNA damage

Question 20

Where is the G2 checkpoint

Answer 20

At the end of the G” phase, beofre the start of the mitotic phase

Question 21

What does the G2 checkpoint check for

Answer 21

• Cell size
• DNA replication
• DNA damage

Question 22

Where is the spindle assembly checkpoint

Answer 22

At the point in mitosis where all the chromosomes should be attached to spindles

Question 23

What does the spindle assembly checkpoint check for

Answer 23

Chromosome attachment to the spindle