The cell cycle 6.1

Question 1

what does mitosis produced

brief

Answer 1

forms to 2 genetically identical daughter cells

Question 2

what are the 2 main phases of the mitosis cell cycle

Answer 2

In eukaryotic cells the cell cycle has 2 main phases - interphase and mitotic (division) phase

Question 3

what phase does the cell spend most of its time in

Answer 3

• Cells do not divide continuously
• spend majority of time in interphase perparing for mitotic (division) phase

Question 4

what occurs in mitosis interphase overall

Answer 4

• DNA replicated and checked for errors
• energy stores increases
• organelles replicate
  ^Protein synthesis occurs
• normal metabolic processes occur

Question 5

what are the 3 main stages of interphase

Answer 5

The three main stages are
G1 (first growth phase)
S (synthesis phase)
G2 (growth phase 2)

Question 6

what occurs in G1 in interphase

Answer 6

• proteins are synthesised
• organelles replicate
• cell increases in size
• DNA checked for errors before replication

Question 7

what occurs in the S phase of mitosis

Answer 7

DNA is replicated in the nucleus

Question 8

what occurs in G2 of mitosis

Answer 8

increase in size, energy stores
duplicated DNA is checked for errors

Question 9

what are all the phases of mitosis cell division

Answer 9

G1 (growth phase 1)
S phase (synthesis phase)
G2 (growth phase 2)
pmat
cytokinesis

Question 10

what occurs in cytokinesis (mitotic phase)

Answer 10

The cytoplasm divides and 2 cells are produced

Question 11

what is G0 and what occurs in this phase

Answer 11

G0 is the name given to the phase when the cell leaves the cycle, either temporarily or permanently.
Also called apoptosis

Question 12

For what reasons could a cell go into G0

Answer 12

• specalised cells are no longer able to divide
• DNA of cell may be damaged, can longer divide
• cells become senescent
  ^cell ages & permanently stops dividing but doesn’t die

Question 13

Can cells go back into the cell cycle from G0

Answer 13

• few can be stimulated to go back into the cell cycle and start dividing again
  ^e.g. lymphocytes in an immune response

Question 14

what is the function of checkpoints in the cell cycle

Answer 14

• checks that each phase of cell cycle has been completed properly before entering next phase

Question 15

what are the checkpoints in the cell cycle (mitosis)

Answer 15

G1 checkpoint
G2 checkpoint
spindle assembly checkpoint

Question 16

what does G1 checkpoint check for

Answer 16

cell size, nutrients, growth factors, Dna damage

Question 17

what does the g2 checkpoint check for

Answer 17

checks for cell size
checks for DNA replication
checks Replicated DNA errors have been repaired

Question 18

How is the spindle assembly checkpoint passed and where is it located in the cell cycle

Answer 18

all the chromosomes should be attached to spindles and have aligned.
at end of metaphase

Question 19

What enzyme brings about the passing of checkpoints

Answer 19

Kinases

Question 20

what is the most common cause of tumors

Answer 20

damage or mutations to genes in proteins used in cell cycle