The cell cycle

Question 1

what does the cell cycle result in

Answer 1

division of the cell and the formation of two new genetically identical daughter cells

Question 2

what are the two main phases of the cell cycle

Answer 2

interphase
mitotic phase (division)

Question 3

interphase is the _______ phase in the cell cycle

Answer 3

longest

Question 4

what happens during interphase

Answer 4

• DNA is replicated and checked for errors in the nucleus
• Protein synthesis occurs in the cytoplasm
• mitochondria grow and divide
• chloroplast grow and divide (in plant and algal cytoplasm)
• normal metabolic processes of cells occur

Question 5

what are the three stages of interphase

Answer 5

G1
S
G2

Question 6

what happens in G1

Answer 6

the first growth phase
proteins from which organelles are synthesised are produced and organelles replicate.
the cell increases in size

Question 7

what happens in S

Answer 7

synthesis phase
DNA is replicated in the nucleus

Question 8

what happens in G2

Answer 8

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

Question 9

what happens during mitotic phase

Answer 9

the period of cell division. cell division involves mitosis and cytokinesis

Question 10

what is mitosis

Answer 10

nucleus dividing

Question 11

what is cytokinesis

Answer 11

cytoplasm divides and two new cells are produced

Question 12

what is G0

Answer 12

the phase where the cell leaves the cell cycle temporarily or permanently

Question 13

why may the cell enter G0 / leave the cell cycle

Answer 13

differentiation- a cell that becomes specialised can no longer divide
the DNA of a cell may be damaged in which case it can no longer divide

Question 14

how is the cell cycle controlled

Answer 14

checkpoints

Question 15

what is the purpose of checkpoints

Answer 15

they monitor and verify whether the processes at each stage of the cell cycle have been accurately completed before the cell progresses to the next phase

Question 16

checkpoint at G1

Answer 16

before entry to S phase
if cell satisfies checkpoint’s requirements it is triggered to begin DNA replication
if not, it enters resting phase (G0)

Question 17

checkpoint at G2

Answer 17

before start of mitotic phase
checks DNA has been replicated without error
if checkpoint passed, cell initiates molecular processes that signal the beginning of mitosis

Question 18

checkpoint at spindle assembly

Answer 18

is at the point in mitosis where all the chromosomes should be attached to spindles and have aligned. mitosis cannot proceed until this checkpoint is passed