Cell Cycle

Question 1

The cell cycle is divided into which main phases

Answer 1

Mitosis and interphase

Question 2

Phases of interphase

Answer 2

G1, S, G2

Question 3

Rapidly renewing human cells progress through the full cycle in about 24 hours. T/F

Answer 3

T

Question 4

What happens in G1?

Answer 4

The cell acquires nutrients, and synthesizes RNA and proteins for DNA synthesis

Question 5

Checkpoint/s of G1

Answer 5

G1 DNA-damage checkpoint, and restriction point

Question 6

What happens in S?

Answer 6

DNA is replicated

Question 7

Checkpoint/s of S

Answer 7

S DNA-damage chckpoint

Question 8

What happens in G2?

Answer 8

The cell prepares to divide

Question 9

Checkpoint/s of G2

Answer 9

G2 DNA-damage checkpoint, and unreplicated-DNA checkpoint

Question 10

Checkpoint/s of mitosis

Answer 10

Spindle-assembly checkpoint and chromosome-regregation checkpoint

Question 11

From what stage does a dividing cell leave the cell cycle?

A. M Phase
B. G1 Phase
C. S Phase
D. G2 Phase

Answer 11

B

Question 12

In rapidly dividing embryonic cells, in what stages of the cell cycle will most cells be in?

A. M + G1 
B. M + S 
C. M + G2 
D. G1 + G2 
E. S + G2

Answer 12

B

Question 13

Which cyclin increases in concentration as a dividing cell exits interphase?

A. Cyclin A 
B. Cyclin B 
C. Cyclin C 
D. Cyclin D 
E. Cyclin E

Answer 13

B

Question 14

Which of the following cyclin is present in most stages of the cell cycle?

A. A 
B. B 
C. C 
D. D
E. E

Answer 14

`D

Question 15

Which of the following is NOT a characteristic of the Restriction (R) Point of the cell cycle?

A. It is within the G1 phase
B. Commits the cell to divide
C. The cell becomes insensitive to mitogens beyond this point
D. Signals the cell to exit the cycle and enter G0 phase

Answer 15

D

Question 16

Which of the following is NOT a mode of CDK regulation?

A. interactions with CDK inhibitors
B. ubiquitination of cyclins
C. acetylation of CDKs
D. phosphorylation of CDKs

Answer 16

C

Question 17

Which chemical modification mediates the destruction of cyclins?

A. ubiquitination 
B. phosphorylation
C. methylation 
D. dephosphorylation 
E. acetylation

Answer 17

A

Question 18

Which of the following BEST describes cyclin?

A. It does not have intrinsic enzymatic activity.
B. It binds to cdk.
C. It is synthesized and degraded each cell cycle.
D. All of the above
E. A and B only

Answer 18

D

Question 19

Which of the following BEST describe cell cycle arrest?

A. Asynchronous profile with flow cytometry
B. G1 accumulation of cell population
C. S-phase activation
D. All of the above

Answer 19

B

Question 20

Which cyclin is involved in the M to G1 phase?

A. Cyclin D
B. Cyclin E
C. Cyclin B
D. Cyclin A

Answer 20

A

Question 21

Which cyclin is involved in the G1 to S phase?

A. Cyclin D
B. Cyclin E
C. Cyclin B
D. Cyclin A

Answer 21

B

Question 22

How does p53 regulate cell cycle?

A. It activates p21 gene. 
B. It deactivates pRb gene. 
C. It disrupts G1 to S phase. 
D. All of the above 
E. A and B only

Answer 22

D

Question 23

Which of the ff. statements may explain why cancer cells are able to evade apoptosis?

A. loss of p53 function 
B. overexpression of Bax 
C. overexpression of Bcl-2 
D. A & C 
E. AOTA

Answer 23

D

Question 24

Which of the following best describes cyclin:

a. Synthesize and degrade during each cell cycle
b. Binds to cdk
c. Does not have internal enzymatic process
d. Both a and b
e. All of the above

Answer 24

e

Question 25

Phases of mitosis

Answer 25

Prophase, Metaphase, Anaphase, Telophase

Question 26

Cytokinesis is a phase of mitosis. T/F

Answer 26

F Mitosis is a process of chromosome segregation and nuclear division. This need not involve division of cytoplasm.

Question 27

Mitotic phase where replicated chromosomes condense and become visible

Answer 27

Prophase

Question 28

Mitotic phase where the nucleolus disappears

Answer 28

Prometaphase or late prophase

Question 29

Mitotic phase where the nuclear envelope begins to disintegrate into small transport vessicles

Answer 29

Prometaphase or late prophase

Question 30

Ring of proteins that hold together sister chromatids

Answer 30

Cohesins and centromere

Question 31

A highly specialized protein complex that appears on each chromatid opposite ot the centromere

Answer 31

Kinetochore

Question 32

Mitotic phase beginning with the mitotic spindle

Answer 32

Metaphase

Question 33

Mitotic spindle is made of which structural protein?

Answer 33

Microtubules

Question 34

Mitotic phase where the chromosomes aline at the central plane of the cell

Answer 34

Metaphase

Question 35

Mitotic phase where the sister chromatids separate

Answer 35

Anaphase

Question 36

Mitotic phase where the nuclear envelope around the chromosomes are restored

Answer 36

Telophase

Question 37

The gene for kinesin was knocked out. In which stage of mitosis would the cells be stuck? a. prophase b. prometaphase c. metaphase d. anaphase e. telophase

Answer 37

b

Question 38

Which of the following results from an unregulated cell division? a. Protooncogene is active b. Tumor suppresor genes are active c. Oncogenes are inactive d. None of the above

Answer 38

d

Question 39

What is true about interphase? a. Dependent on 1 type of cyclin b. Metabolically less active than G0 c. Cell size is fixed d. Chromosome number is not constant

Answer 39

d

Question 40

What will be the cellular outcome when there is a longer persistence of activated CDKs during G1? a. Shorter G2 length b. Hypertrophic cell c. G1 arrest d. Smaller cell volume

Answer 40

b

Question 41

Which of the following is not true about cytokinesis? a. Involves actin b. Highly dependent on ATP c. Involves microtubules d. Initiates after mitosis

Answer 41

d

Question 42

In cancer, which cell cycle stage is responsible for insensitivity to growth inhibition? a. G1 b. S c. G2 d. M

Answer 42

a

Question 43

Which of the following is a feature of the early divisions of embryonic cells? a. No G1 and G2 b. No G1, Short G2 c. Short G1, no G2 d. Short G1 and G2

Answer 43

b

Question 44

Which of the following will result from non-polyubiquitination of cyclin B? a. Uncontrolled continuous nuclear division b. Non-entry to the M phase c. Exit out of the cell cycle to G0 d. Arrest of nuclear division

Answer 44

D

Question 45

Which cell cycle stage determines commitment to go through the cell cycle? (R Point) a. G1 b. S c. G2 d. M

Answer 45

A

Question 46

Which cell stage is most sensitive to oncogene activity? a. G1 b. S c. G2 d. M

Answer 46

A

Question 47

Which is least likely to result in uncontrolled cell division? a. Mutation in both tumor suppressor alleles b. Oncogene that is always active c. Deletion of a proto-concogene gene d. An inhibition-resistant tumor suppressor protein

Answer 47

C

Question 48

Which of the following is not a means of controlling CDKs? a. Phosphorylation b. DNAse activation c. Binding by inhibitors d. Amount of cyclins

Answer 48

B

Question 49

Which of the following is true about apoptosis? a. Presence of inflammation b. Cause by chemical injury c. Cleared by phagocytosis d. Cellular leakage

Answer 49

c