Question 1

In which of the following cell types do G1 and G2 not take place?

Accepted Answer

A)   Early embryonic cells
B)   Budding yeast cells
C)   Typical proliferating human cells
D)   Skin fibroblasts A

Question 2

Transcription ceases as chromosome condensation occurs.

Accepted Answer

A) True 
 B)False

Question 3

Why is Rb, a product of the retinoblastoma gene, now termed a member of a family of proteins designated tumor suppressor genes?

Accepted Answer

Normally, Rb exists in an underphosphory...

Question 4

The G1 checkpoint in budding yeast cells is called

Accepted Answer

A)   START.
B)   the restriction point.
C)   the decision point.
D)   the G1/S boundary.

Question 5

Two sea urchin proteins were named cyclin A and B because, during the embryonic cell cycle, they were periodically

Accepted Answer

A)   activated and inactivated by phosphorylation and dephosphorylation.
B)   synthesized and degraded.
C)   bound and released by another protein.
D)   ubiquitylated and nonubiquitylated.

Question 6

Chromosomes are attached to spindle microtubules by

Accepted Answer

A)   centromeres.
B)   kinetochores.
C)   centrioles.
D)   centrosomes.

Question 7

The eukaryotic cell cycle is composed of four phases in the following order:

Accepted Answer

A)   G1; S; G2; M.
B)   G1; G2; S; M.
C)   G1; M; G2; S.
D)   S; G1; G2; M.

Question 8

Entry into mitosis occurs because

Accepted Answer

A)   cyclin is destroyed at the beginning of mitosis.
B)   cyclin is phosphorylated at the beginning of mitosis.
C)   sufficient cyclin-dependent kinase is synthesized to trigger mitosis.
D)   Cdk1/Cyclin B (MPF)  get activated.

Question 9

The DNA region to which proteins bind to form the kinetochore and spindle fibers attach for segregation of the chromosomes is called the

Accepted Answer

A)   chiasma.
B)   centromere.
C)   synaptonemal complex.
D)   origin.

Question 10

The progression from metaphase to anaphase results from

Accepted Answer

A)   phosphorylation mediated by Polo-like kinase.
B)   ubiquitin-mediated proteolysis of key regulatory proteins.
C)   phosphorylation mediated by Cdk2.
D)   activation by Wee1.

Question 11

The spindle assembly checkpoint monitors the alignment of chromosomes on the _______.

Accepted Answer

The answer of The spindle assembly checkpoint monitors the alignment...

Question 12

Rb is a tumor suppressor protein that acts by inhibiting phosphorylation of Cdk.

Accepted Answer

A) True 
 B)False

Question 13

In yeast, START triggers the progression from G1 to S. Which of the following are involved in regulating START?

Accepted Answer

A)   Nutrients
B)   Mating factors
C)   Cell size
D)   All of the above

Question 14

The degradation of cyclin B during _______ occurs after it becomes modified by the addition of ubiquitin.

Accepted Answer

The answer of The degradation of cyclin B during _______...

Question 15

Briefly describe how Hunt and colleagues identified cyclins and why they named them "cyclins"?

Accepted Answer

Hunt et al. knew that upon fertilization...

Question 16

What event takes place during interphase?

Accepted Answer

A)   Centromeres divide.
B)   Metabolic processes, such as DNA replication, are carried out by the cell.
C)   Spindle fibers start forming.
D)   Centrioles begin to appear. B

Question 17

Injection of MPF into frog oocytes induces them to enter _______.

Accepted Answer

The answer of Injection of MPF into frog oocytes induces...

Question 18

Which of the following is not one of the phases of mitosis?

Accepted Answer

A)   Prophase
B)   S phase
C)   Metaphase
D)   Anaphase

Question 19

In animal cells, Cdk2/cyclin A act to drive cells through the restriction point in G1.

Accepted Answer

A) True 
 B)False

Question 20

Identify the four different molecular mechanisms by which the activity of cyclin-dependent kinases is regulated after they are synthesized.

Accepted Answer

(1) Association of a Cdk with its partner cyclin; (2) phosphorylation of an activating threonine; (3) phosphorylation and dephosphorylation of inhibiting tyrosine and threonine residues; and (4) binding of Cdk inhibitors.

Exam 18: The Cell Cycle

In which of the following cell types do G1 and G2 not take place?

Correct AnswerverifiedA

Transcription ceases as chromosome condensation occurs.

Correct AnswerverifiedShow Answer

Why is Rb, a product of the retinoblastoma gene, now termed a member of a family of proteins designated tumor suppressor genes?

Correct AnswerverifiedNormally, Rb exists in an underphosphory...View AnswerShow Answer

The G1 checkpoint in budding yeast cells is called

Correct AnswerverifiedShow Answer

Two sea urchin proteins were named cyclin A and B because, during the embryonic cell cycle, they were periodically

Correct AnswerverifiedShow Answer

Chromosomes are attached to spindle microtubules by

Correct AnswerverifiedShow Answer

The eukaryotic cell cycle is composed of four phases in the following order:

Correct AnswerverifiedShow Answer

Entry into mitosis occurs because

Correct AnswerverifiedShow Answer

The DNA region to which proteins bind to form the kinetochore and spindle fibers attach for segregation of the chromosomes is called the

Correct AnswerverifiedShow Answer

The progression from metaphase to anaphase results from

Correct AnswerverifiedShow Answer

The spindle assembly checkpoint monitors the alignment of chromosomes on the _______.

Correct AnswerverifiedShow Answer

Rb is a tumor suppressor protein that acts by inhibiting phosphorylation of Cdk.

Correct AnswerverifiedShow Answer

In yeast, START triggers the progression from G1 to S. Which of the following are involved in regulating START?

Correct AnswerverifiedShow Answer

The degradation of cyclin B during _______ occurs after it becomes modified by the addition of ubiquitin.

Correct AnswerverifiedShow Answer

Briefly describe how Hunt and colleagues identified cyclins and why they named them "cyclins"?

Correct AnswerverifiedHunt et al. knew that upon fertilization...View AnswerShow Answer

What event takes place during interphase?

Correct AnswerverifiedB

Injection of MPF into frog oocytes induces them to enter _______.

Correct AnswerverifiedShow Answer

Which of the following is not one of the phases of mitosis?

Correct AnswerverifiedShow Answer

In animal cells, Cdk2/cyclin A act to drive cells through the restriction point in G1.

Correct AnswerverifiedShow Answer

Identify the four different molecular mechanisms by which the activity of cyclin-dependent kinases is regulated after they are synthesized.

Correct Answerverified(1) Association of a Cdk with its partner cyclin; (2) phosphorylation of an activating threonine; (3) phosphorylation and dephosphorylation of inhibiting tyrosine and threonine residues; and (4) binding of Cdk inhibitors.

In which of the following cell types do G₁ and G₂ not take place?

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A

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Normally, Rb exists in an underphosphory...
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The G₁ checkpoint in budding yeast cells is called

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In yeast, START triggers the progression from G₁ to S. Which of the following are involved in regulating START?

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Hunt et al. knew that upon fertilization...
View Answer

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B

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In animal cells, Cdk2/cyclin A act to drive cells through the restriction point in G₁.

Correct Answer
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(1) Association of a Cdk with its partner cyclin; (2) phosphorylation of an activating threonine; (3) phosphorylation and dephosphorylation of inhibiting tyrosine and threonine residues; and (4) binding of Cdk inhibitors.