MMSC490 COMPREHENSIVE EXAM 2026 TEST
PAPER QUESTIONS AND SOLUTIONS
◍ The length of time it takes for the cells labeled during DNA synthesis
to begin to enter mitosis is a good estimate of the length of the _______
phase(s).
a. G1
b. S
c. G2
d. M . Answer: C
◍ In a typical cycling mammalian cell, _______ of the cell cycle is
spent in interphase.
a. 99%
b. 95%
c. 75%
d. 50% . Answer: B
◍ Cell cycles of early embryonic animal cells are unusual because they
have
a. no G1 or G2.
,b. an elongated G1 and G2.
c. a short S.
d. a much shortened M. . Answer: A
◍ The number of cells in the different phases of a population can be
determined most easily by using a(n) _______ to measure the amount of
DNA per cell in a large sample of cells.
a. scintillation counter
b. flow cytometer
c. fluorescence microscope
d. phase-contrast microscope after autoradiography . Answer: B
◍ Which of the following represents the amount of DNA in a typical G2
cell?
a. n
b. 2n
c. 4n
d. 8n . Answer: C
◍ The G1 checkpoint in budding yeast cells is called
a. START.
b. the restriction point.
c. the decision point.
,d. the G1/S boundary. . Answer: A
◍ The G1 checkpoint in animal cells is called
a. START.
b. the restriction point.
c. the decision point.
d. the G1/S boundary. . Answer: B
◍ Skin fibroblasts arrested in G0 are stimulated near a wound to enter
G1 by _______ growth factor.
a. epidermal
b. fibroblast
c. platelet-derived
d. keratinocyte . Answer: C
◍ The G2 checkpoint prevents entry into _______ if _______.
a. G1; DNA synthesis is not complete and/or DNA is damaged
b. S; DNA synthesis is not complete and/or DNA is damaged
c. G2; DNA synthesis is not complete and/or DNA is damaged
d. M; DNA synthesis is not complete and/or DNA is damaged . Answer:
D
, ◍ Maturation promotion factor (MPF), discovered by Masui and
Markert, is the factor that
a. is missing in the cdc2 mutant in yeast.
b. induces entry into meiosis when injected into frog oocytes.
c. fluctuates in amount during early cleavages of sea urchin eggs.
d. fluctuates in amount during the cell cycle of mammalian cells. .
Answer: B
◍ MPF is a
a. monomeric protein kinase.
b. dimer of two molecules of Cdk1.
c. dimer of Cdk1 and cyclin A.
d. dimer of Cdk1 and cyclin B. . Answer: D
◍ MPF is a general regulator of the transition from
a. G1 to S.
b. S to G2.
c. G2 to M.
d. metaphase to anaphase. . Answer: C
◍ Studies on cell cycle mutants in budding and fission yeasts
demonstrated that cdc2 and cdc28 both encode a
a. protein kinase.
PAPER QUESTIONS AND SOLUTIONS
◍ The length of time it takes for the cells labeled during DNA synthesis
to begin to enter mitosis is a good estimate of the length of the _______
phase(s).
a. G1
b. S
c. G2
d. M . Answer: C
◍ In a typical cycling mammalian cell, _______ of the cell cycle is
spent in interphase.
a. 99%
b. 95%
c. 75%
d. 50% . Answer: B
◍ Cell cycles of early embryonic animal cells are unusual because they
have
a. no G1 or G2.
,b. an elongated G1 and G2.
c. a short S.
d. a much shortened M. . Answer: A
◍ The number of cells in the different phases of a population can be
determined most easily by using a(n) _______ to measure the amount of
DNA per cell in a large sample of cells.
a. scintillation counter
b. flow cytometer
c. fluorescence microscope
d. phase-contrast microscope after autoradiography . Answer: B
◍ Which of the following represents the amount of DNA in a typical G2
cell?
a. n
b. 2n
c. 4n
d. 8n . Answer: C
◍ The G1 checkpoint in budding yeast cells is called
a. START.
b. the restriction point.
c. the decision point.
,d. the G1/S boundary. . Answer: A
◍ The G1 checkpoint in animal cells is called
a. START.
b. the restriction point.
c. the decision point.
d. the G1/S boundary. . Answer: B
◍ Skin fibroblasts arrested in G0 are stimulated near a wound to enter
G1 by _______ growth factor.
a. epidermal
b. fibroblast
c. platelet-derived
d. keratinocyte . Answer: C
◍ The G2 checkpoint prevents entry into _______ if _______.
a. G1; DNA synthesis is not complete and/or DNA is damaged
b. S; DNA synthesis is not complete and/or DNA is damaged
c. G2; DNA synthesis is not complete and/or DNA is damaged
d. M; DNA synthesis is not complete and/or DNA is damaged . Answer:
D
, ◍ Maturation promotion factor (MPF), discovered by Masui and
Markert, is the factor that
a. is missing in the cdc2 mutant in yeast.
b. induces entry into meiosis when injected into frog oocytes.
c. fluctuates in amount during early cleavages of sea urchin eggs.
d. fluctuates in amount during the cell cycle of mammalian cells. .
Answer: B
◍ MPF is a
a. monomeric protein kinase.
b. dimer of two molecules of Cdk1.
c. dimer of Cdk1 and cyclin A.
d. dimer of Cdk1 and cyclin B. . Answer: D
◍ MPF is a general regulator of the transition from
a. G1 to S.
b. S to G2.
c. G2 to M.
d. metaphase to anaphase. . Answer: C
◍ Studies on cell cycle mutants in budding and fission yeasts
demonstrated that cdc2 and cdc28 both encode a
a. protein kinase.
