2.6 Cell cycle (interphase)

Question 1

What phase does a cell spend most it’s time in?

Answer 1

Interphase

Question 2

What are the long periods of growth called?

Answer 2

Interphase

Question 3

What happens to the DNA during interphase?

Answer 3

It is replicated and checked for errors

Question 4

What occurs in the cytoplasm during interphase?

Answer 4

Protein synthesis

Question 5

What grows and divides during interphase?

Answer 5

• mitochondria

* chloroplasts (in plant and agal cells)

Question 6

What else occurs in interphase?

Answer 6

Normal metabolic processes (cell respiration)

Question 7

What are the 3 stages/phases of interphase?

Answer 7

• G1
• S
• G2

Question 8

What is G1 and what occurs here?

Answer 8

• first growth phase
• organelles replicate
• cell increases in size
• proteins from which organelles are synthesised are produced

Question 9

What is the S phase and what occurs here?

Answer 9

• synthesis phase

* DNA in the nucleus is replicated

Question 10

What is G2 and what occurs here?

Answer 10

• second growth phase
• cell increases in size
• DNA checked for errors
• energy stores increased

Question 11

What are the two main phases of the cell cycle?

Answer 11

• interphase

* mitotic phase

Question 12

What happens after interphase?

Answer 12

The mitotic phase

Question 13

What is G0?

Answer 13

The phase where the cell leaves the cycle (temporarily or permanently)

Question 14

What reasons are there for the G0 phase?

Answer 14

• differentiation
• errors/ damaged DNA
• age

Question 15

Why do cells enter the G0 phase due to differentiation?

Answer 15

• cells become specialised and can no longer divide and enter the cell cycle

Question 16

Why does the cell enter the G0 phase due to DNA damage?

Answer 16

• a damaged cell can no longer divide

* enters a period of permanent arrest

Question 17

Why do cells enter the G0 phase due to age?

Answer 17

• become senescent

* senescent cells are linked with age related diseases such as cancer and arthritis

Question 18

What types of cells can be stimulated and return back to the cell cycle from the G0 phase?

Answer 18

Lymphocytes (white blood cells) in a immune response

Question 19

What are checkpoints?

Answer 19

The control mechanisms of the cell cycle

Question 20

What occurs at checkpoints?

Answer 20

Monitoring and verifying wether processes at each stage of the cell cycle have been accurately completed before cells progress to the next stage

Question 21

What are the 3 checkpoints?

Answer 21

G1 checkpoint
G2 checkpoint
Spindle assembly point

Question 22

What checks are made at the G1 checkpoint?

Answer 22

Check for cell size, Cell growth and DNA damage

Question 23

What checks are made at the G2 checkpoint?

Answer 23

Checks for cell size, DNA replication and DNA damage

Question 24

What checks are made at the spindle assembly point?

Answer 24

Checks that chromosomes are attached to spindles