Cell Cycle

Question 1

3 Steps of Cell Cycle

Answer 1

1. Cell Growth/ Chromosome Duplication
2. Chromosome Segregation
3. Cell Division

Question 2

cells reproduce by duplicating their contents and dividing in two

Answer 2

cell cycle

Question 3

4 Phases of Cell Cycle

Answer 3

1. G1
2. S
3. G2
4. M

Question 4

What happens during G1 and G2 (interphase) phases?

Answer 4

cell continues to grow while being monitored

Question 5

What happens during the S phase?

Answer 5

cell replicates its DNA (synthesis)

Question 6

What 2 things happen during the M phase?

Answer 6

mitosis and cytokinesis

Question 7

when the nucleus divides

Answer 7

mitosis

Question 8

when the cell splits into two/ cytoplasm divides

Answer 8

cytokinesis

Question 9

A number of checkpoints are accomplished in order to move to next phase of the cell cycle. (T or F)

Answer 9

True

Question 10

Progression through the cell cycle depends on what?

Answer 10

cyclin-dependent protein kinases (Cdks)

Question 11

The amount of cyclins stay constant throughout the cell cycle. (T or F)

Answer 11

False, the abundance varies to regulate activity of Cdks

Question 12

Distinct Cdks associate with different cyclins to trigger the different events of the cell cycle. (T or F)

Answer 12

True

Question 13

Link the 4 cyclin-Cdk complexes to the cyclin

Answer 13

G1-Cdk : cyclin D
G1/S-Cdk : cyclin E
S-Cdk : cyclin A
M-Cdk : cyclin B

Question 14

Some Cdk activity is regulated by cyclin degradation. (T or F)

Answer 14

True

Question 15

For S-Cdk to be active, inhibitory phosphates must be removed. (T or F)

Answer 15

False, for M-Cdk

Question 16

The activity of a Cdk can be blocked by the binding of a Cdk inhibitor. (T or F)

Answer 16

True

Question 17

Inhibition of activating phosphatase blocks entry to which phase?

Answer 17

mitosis

Question 18

Inhibition of APC activation delays exits from which phase?

Answer 18

mitosis

Question 19

Cdk inhibitors block entry to which phase?

Answer 19

S phase

Question 20

DNA damage can arrest the cell cycle in G2 phase. (T or F)

Answer 20

False, G1 phase

Question 21

Describe 2 Steps of the Initiation of DNA Replication

Answer 21

1. In G1, Cdc6 binds to ORC loading a pair of DNA helicases to form a pre-replicative complex.
2. In S phase, S-Cdk triggers replicative complex to start DNA synthesis at replication fork.

Question 22

At mitosis, activated M-Cdk indirectly activates more M-Cdk, creating a negative feedback loop. (T or F)

Answer 22

False, a positive feedback loop

Question 23

5 Steps of Mitosis

Answer 23

1. Prophase
2. Prometaphase
3. Metaphase
4. Anaphase
5. Telophase

Question 24

What happens during interphase? (3)

Answer 24

-cell increases in size
-DNA of chromosomes replicated
-centrosome duplicated

Question 25

What happens during prophase? (2)

Answer 25

-duplicated chromosomes condense -mitotic spindle assembles between two centrosomes

Question 26

Chromosomes in prophase consist of two sister chromatids. (T or F)

Answer 26

True

Question 27

What happens during prometaphase? (2)

Answer 27

-breakdown of nuclear envelope -chromosomes attach to spindle microtubules and undergo movement

Question 28

What happens during metaphase? (2)

Answer 28

-chromosomes align at equator of spindle -each sister chromatid attaches to opposite spindle pole

Question 29

What happens during anaphase? (1)

Answer 29

-sister chromatids separate and are pulled to spindle poles (chromosome segregation)

Question 30

What happens during telophase? (2)

Answer 30

-sets of chromosomes arrive at the poles -new nuclear envelope reassembles forming two separate nuclei

Question 31

tie together two adjacent sister chromatids in each duplicated chromosome

Answer 31

cohesins

Question 32

help coil each sister chromatid into a smaller, more compact structure easier to segregate

Answer 32

condensins

Question 33

The cytoskeleton plays an essential role in mitosis. (T or F)

Answer 33

True

Question 34

In what two phases are centrioles replicated?

Answer 34

S and G2 phases

Question 35

Microtubules don't move during chromosome segregation. (T or F)

Answer 35

False, they move and rearrange

Question 36

Where do microtubules attach to on the chromosomes?

Answer 36

the kinetochore

Question 37

Name the 3 classes on microtubules found in the mitotic apparatus

Answer 37

1. Aster 2. Kinetochore 3. Interpolar

Question 38

What does APC trigger?

Answer 38

the separation of sister chromatids by promoting the destruction of cohesins