MMSC490 Exam 2 (2025) Actual Exam
Questions and Answers A+ Graded
Which .eukaryotic .DNA .polymerase .replicates .the .lagging .strand .in .the .3ʹ .to .5ʹ
.direction? .
a. .α .
b. .γ .
c. .δ .
d. .None .of .the .above; .the .lagging .strand .is .replicated .in .the .5ʹ .to .3ʹ .direction. .-
.CORRECT .ANSWER-d. .None .of .the .above; .the .lagging .strand .is .replicated .in
.the .5ʹ .to .3ʹ .direction.
DNA .polymerases .can .synthesize .DNA:
a. .de .novo, .by .catalyzing .the .polymerization .of .free .dNTPs. .
b. .by .adding .dNTPs .to .complementary .dNTPs .on .a .single-stranded .DNA. .
c. .by .adding .dNTPs .to .a .hydroxyl .group .on .the .end .of .a .growing
.polynucleotide .chain .hydrogen-bonded .to .a .strand .of .RNA. .
d. .by .adding .dNTPs .to .a .hydroxyl .group .on .the .end .of .a .growing
.polynucleotide .chain .hydrogen-bonded .to .a .strand .of .DNA. .- .CORRECT
.ANSWER-d. .by .adding .dNTPs .to .a .hydroxyl .group .on .the .end .of .a .growing
.polynucleotide .chain .hydrogen-bonded .to .a .strand .of .DNA.
In .addition .to .synthesizing .DNA, .DNA .polymerase .I .has .a .second .catalytic
.activity: .it .can .
a. .synthesize .short .RNA .sequences. .
b. .synthesize .short .polypeptide .sequences. .
c. .remove .RNA .primers. .
d. .ligate .short .segments .of .DNA .together. .- .CORRECT .ANSWER-c. .remove .RNA
.primers.
Which .eukaryotic .DNA .polymerase .replicates .the .leading .strand .in .the .5ʹ .to .3ʹ
.direction? .
a. .α .
b. .ε .
c. .δ .
d. .γ .- .CORRECT .ANSWER-b. .ε
Free .rotation .of .one .cut .DNA .strand .around .one .uncut .strand .is .the .primary
.function .of: .
a. .topoisomerase .I. .
,b. .topoisomerase .II. .
c. .DNA .helicase. .
d. .DNA .polymerase. .- .CORRECT .ANSWER-a. .topoisomerase .I.
The .function .of .topoisomerase .II .is .to: .
a. .resolve .DNA .tangles. .
b. .allow .DNA .to .swivel .and .unwind.
c. .allow .daughter .chr
d. .all .of .the .above .- .CORRECT .ANSWER-d. .all .of .the .above
Autonomously .replicating .sequences .are:
a. .yeast .plasmids. .
b. .yeast .telomeres. .
c. .bacterial .plasmids. .
d. .yeast .origins .of .replication. .- .CORRECT .ANSWER-d. .yeast .origins .of
.replication.
Telomeres .are .the:
a. .midpoints .of .chromosomes. .
b. .microtubule .attachment .points .on .chromosomes. .c. .end-sequences .of
.chromosomes. .
d. .enzyme .complexes .that .complete .DNA .replication. .- .CORRECT .ANSWER-c.
.end-sequences .of .chromosomes.
Point .mutations .in .DNA .result .from:
a. .incorporation .of .incorrect .bases .during .replication. .
b. .changes .as .a .result .of .chemical .exposure. .
c. .changes .as .a .result .of .radiation .exposure. .
d. .All .of .the .above .- .CORRECT .ANSWER-d. .All .of .the .above
The .most .common .cause .of .skin .cancer .is .damage .to .DNA .by:
a. .infrared .light. .
b. .ultraviolet .light.
c. .γ .radiation. .
d. .β .particle .radiation. .- .CORRECT .ANSWER-b. .ultraviolet .light.
Pyrimidine .dimers:
a. .block .DNA .replication .and .transcription. .
b. .can .be .repaired .by .photoreactivation. .
c. .can .be .repaired .by .nucleotide-excision .repair. .
d. .All .of .the .above .- .CORRECT .ANSWER-d. .All .of .the .above
Cultured .cells .from .xeroderma .pigmentosum .patients .were .unable .to .carry .out:
a. .base-excision .repair. .
b. .nucleotide-excision .repair. .
c. .synthesis .of .melanin. .
d. .DNA .synthesis. .- .CORRECT .ANSWER-b. .nucleotide-excision .repair.
E. .coli .DNA .polymerase .V:
,a. .is .induced .in .response .to .high .temperatures. .
b. .recognizes .thymidine .dimers .and .inserts .nucleotides .on .the .opposite .strand.
.
c. .has .a .low .frequency .of .errors. .
d. .is .activated .during .transcription. .- .CORRECT .ANSWER-b. .recognizes
.thymidine .dimers .and .inserts .nucleotides .on .the .opposite .strand.
Site-specific .recombination:
a. .occurs .in .randomly .occurring .DNA .sequences. .
b. .is .mediated .by .proteins .that .recognize .specific .DNA .target .sequences. .
c. .leads .to .programmed .cell .death. .
d. .is .also .referred .to .as .homologous .recombination. .- .CORRECT .ANSWER-b. .is
.mediated .by .proteins .that .recognize .specific .DNA .target .sequences.
Site-specific .recombination .occurs .commonly .during:
a. .mitosis .of .somatic .cells. .
b. .meiosis .of .germ .cells. .
c. .development .of .immune-system .cells. .
d. .prokaryotic .cell .division. .- .CORRECT .ANSWER-c. .development .of .immune-
system .cells.
The .DNA .sequence .to .which .an .RNA .polymerase .binds .to .initiate .transcription
.of .a .gene .is .called .a(n): .
a. .enhancer. .
b. .promoter. .
c. .polymerase-binding .element. .
d. .origin .of .transcription. .- .CORRECT .ANSWER-b. .promoter.
The .regions .of .the .DNA .where .RNA .polymerase .binds .can .be .identified .by:
a. .restriction .mapping. .
b. .PCR. .
c. .mutagenesis .in .the .-35 .and .-10 .promoter .regions .that .inhibits .transcription. .
d. .polymerase .mapping. .- .CORRECT .ANSWER-c. .mutagenesis .in .the .-35 .and .-
10 .promoter .regions .that .inhibits .transcription.
Termination .of .transcription .in .E. .coli .is .signaled .by: .
a. .formation .of .a .stem-loop .structure .in .the .RNA. .
b. .binding .of .Rho .protein .to .the .end .of .the .mRNA. .
c. .binding .of .a .sigma .(ζ) .factor .to .the .end .of .the .mRNA. .
d. .an .inverted .GC-rich .sequence .followed .by .seven .A .residues. .- .CORRECT
.ANSWER-d. .an .inverted .GC-rich .sequence .followed .by .seven .A .residues.
The .pioneering .studies .of .gene .regulation .in .E. .coli .were .conducted .in .the
.1950s .by:
a. .Miller .and .Urey. .
b. .Watson .and .Crick. .
c. .Jacob .and .Monod. .
d. .Lerner .and .Lowe. .- .CORRECT .ANSWER-c. .Jacob .and .Monod.
The .lac .operator .consists .of .approximately .20 .base .pairs .of .DNA .located:
, .a. .80-100 .base .pairs .upstream .of .the .transcription .initiation .site. .
b. .20-40 .base .pairs .upstream .of .the .transcription .initiation .site. .
c. .in .a .position .overlapping .the .initiation .site. .
d. .downstream .of .the .transcription .initiation .site. .- .CORRECT .ANSWER-c. .in .a
.position .overlapping .the .initiation .site.
Catabolite .repression .in .E. .coli:
a. .inhibits .the .breakdown .of .glucose .in .the .presence .of .lactose. .
b. .is .reversed .by .cAMP .binding .to .catabolite .activator .protein. .
c. .inhibits .the .lac .operon .unless .lactose .is .present. .
d. .is .a .negative .feedback .system. .- .CORRECT .ANSWER-b. .is .reversed .by .cAMP
.binding .to .catabolite .activator .protein.
Eukaryotic .RNA .polymerase .I .genes .code .for:
a. .mRNAs. .
b. .tRNAs. .
c. .small .nuclear .RNAs .and .small .cytoplasmic .RNAs. .
d. .ribosomal .RNAs. .- .CORRECT .ANSWER-d. .ribosomal .RNAs.
The .first .step .in .the .formation .of .a .transcription .complex .for .mRNA
.transcription .is .the .binding .of ._______ .to .the .TATA .box.
a. .TFIA .
b. .TFIIA .
c. .TFIIIA .
d. .TFIID .- .CORRECT .ANSWER-d. .TFIID
The .large .multi-subunit .complex .that .links .the .general .transcription .factors .to
.the .genespecific .transcription .factors .is .called:
a. .the .transcription .complex. .
b. .Mediator. .
c. .the .operator. .
d. .TBP. .- .CORRECT .ANSWER-b. .Mediator.
Release .of .RNA .polymerase .II .to .initiate .transcription .appears .to .be .the .direct
.result .of .the:
a. .binding .of .TAFs .to .the .polymerase. .
b. .unwinding .of .the .DNA .by .helicases. .
c. .phosphorylation .of .RNA .polymerase .by .a .protein .kinase. .
d. .removal .of .the .nucleosome .occupying .the .promoter .site. .- .CORRECT
.ANSWER-c. .phosphorylation .of .RNA .polymerase .by .a .protein .kinase.
A .major .difference .between .eukaryotic .and .prokaryotic .RNA .polymerases .is
.that .eukaryotic .polymerases:
a. .use .a .set .of .transcription .factors .to .bind .to .and .initiate .transcription.
b. .use .sigma .() .factors .to .initiate .transcription. .
c. .start .from .promoters. .
d. .start .from .origins .of .replication. .- .CORRECT .ANSWER-a. .use .a .set .of
.transcription .factors .to .bind .to .and .initiate .transcription.
Questions and Answers A+ Graded
Which .eukaryotic .DNA .polymerase .replicates .the .lagging .strand .in .the .3ʹ .to .5ʹ
.direction? .
a. .α .
b. .γ .
c. .δ .
d. .None .of .the .above; .the .lagging .strand .is .replicated .in .the .5ʹ .to .3ʹ .direction. .-
.CORRECT .ANSWER-d. .None .of .the .above; .the .lagging .strand .is .replicated .in
.the .5ʹ .to .3ʹ .direction.
DNA .polymerases .can .synthesize .DNA:
a. .de .novo, .by .catalyzing .the .polymerization .of .free .dNTPs. .
b. .by .adding .dNTPs .to .complementary .dNTPs .on .a .single-stranded .DNA. .
c. .by .adding .dNTPs .to .a .hydroxyl .group .on .the .end .of .a .growing
.polynucleotide .chain .hydrogen-bonded .to .a .strand .of .RNA. .
d. .by .adding .dNTPs .to .a .hydroxyl .group .on .the .end .of .a .growing
.polynucleotide .chain .hydrogen-bonded .to .a .strand .of .DNA. .- .CORRECT
.ANSWER-d. .by .adding .dNTPs .to .a .hydroxyl .group .on .the .end .of .a .growing
.polynucleotide .chain .hydrogen-bonded .to .a .strand .of .DNA.
In .addition .to .synthesizing .DNA, .DNA .polymerase .I .has .a .second .catalytic
.activity: .it .can .
a. .synthesize .short .RNA .sequences. .
b. .synthesize .short .polypeptide .sequences. .
c. .remove .RNA .primers. .
d. .ligate .short .segments .of .DNA .together. .- .CORRECT .ANSWER-c. .remove .RNA
.primers.
Which .eukaryotic .DNA .polymerase .replicates .the .leading .strand .in .the .5ʹ .to .3ʹ
.direction? .
a. .α .
b. .ε .
c. .δ .
d. .γ .- .CORRECT .ANSWER-b. .ε
Free .rotation .of .one .cut .DNA .strand .around .one .uncut .strand .is .the .primary
.function .of: .
a. .topoisomerase .I. .
,b. .topoisomerase .II. .
c. .DNA .helicase. .
d. .DNA .polymerase. .- .CORRECT .ANSWER-a. .topoisomerase .I.
The .function .of .topoisomerase .II .is .to: .
a. .resolve .DNA .tangles. .
b. .allow .DNA .to .swivel .and .unwind.
c. .allow .daughter .chr
d. .all .of .the .above .- .CORRECT .ANSWER-d. .all .of .the .above
Autonomously .replicating .sequences .are:
a. .yeast .plasmids. .
b. .yeast .telomeres. .
c. .bacterial .plasmids. .
d. .yeast .origins .of .replication. .- .CORRECT .ANSWER-d. .yeast .origins .of
.replication.
Telomeres .are .the:
a. .midpoints .of .chromosomes. .
b. .microtubule .attachment .points .on .chromosomes. .c. .end-sequences .of
.chromosomes. .
d. .enzyme .complexes .that .complete .DNA .replication. .- .CORRECT .ANSWER-c.
.end-sequences .of .chromosomes.
Point .mutations .in .DNA .result .from:
a. .incorporation .of .incorrect .bases .during .replication. .
b. .changes .as .a .result .of .chemical .exposure. .
c. .changes .as .a .result .of .radiation .exposure. .
d. .All .of .the .above .- .CORRECT .ANSWER-d. .All .of .the .above
The .most .common .cause .of .skin .cancer .is .damage .to .DNA .by:
a. .infrared .light. .
b. .ultraviolet .light.
c. .γ .radiation. .
d. .β .particle .radiation. .- .CORRECT .ANSWER-b. .ultraviolet .light.
Pyrimidine .dimers:
a. .block .DNA .replication .and .transcription. .
b. .can .be .repaired .by .photoreactivation. .
c. .can .be .repaired .by .nucleotide-excision .repair. .
d. .All .of .the .above .- .CORRECT .ANSWER-d. .All .of .the .above
Cultured .cells .from .xeroderma .pigmentosum .patients .were .unable .to .carry .out:
a. .base-excision .repair. .
b. .nucleotide-excision .repair. .
c. .synthesis .of .melanin. .
d. .DNA .synthesis. .- .CORRECT .ANSWER-b. .nucleotide-excision .repair.
E. .coli .DNA .polymerase .V:
,a. .is .induced .in .response .to .high .temperatures. .
b. .recognizes .thymidine .dimers .and .inserts .nucleotides .on .the .opposite .strand.
.
c. .has .a .low .frequency .of .errors. .
d. .is .activated .during .transcription. .- .CORRECT .ANSWER-b. .recognizes
.thymidine .dimers .and .inserts .nucleotides .on .the .opposite .strand.
Site-specific .recombination:
a. .occurs .in .randomly .occurring .DNA .sequences. .
b. .is .mediated .by .proteins .that .recognize .specific .DNA .target .sequences. .
c. .leads .to .programmed .cell .death. .
d. .is .also .referred .to .as .homologous .recombination. .- .CORRECT .ANSWER-b. .is
.mediated .by .proteins .that .recognize .specific .DNA .target .sequences.
Site-specific .recombination .occurs .commonly .during:
a. .mitosis .of .somatic .cells. .
b. .meiosis .of .germ .cells. .
c. .development .of .immune-system .cells. .
d. .prokaryotic .cell .division. .- .CORRECT .ANSWER-c. .development .of .immune-
system .cells.
The .DNA .sequence .to .which .an .RNA .polymerase .binds .to .initiate .transcription
.of .a .gene .is .called .a(n): .
a. .enhancer. .
b. .promoter. .
c. .polymerase-binding .element. .
d. .origin .of .transcription. .- .CORRECT .ANSWER-b. .promoter.
The .regions .of .the .DNA .where .RNA .polymerase .binds .can .be .identified .by:
a. .restriction .mapping. .
b. .PCR. .
c. .mutagenesis .in .the .-35 .and .-10 .promoter .regions .that .inhibits .transcription. .
d. .polymerase .mapping. .- .CORRECT .ANSWER-c. .mutagenesis .in .the .-35 .and .-
10 .promoter .regions .that .inhibits .transcription.
Termination .of .transcription .in .E. .coli .is .signaled .by: .
a. .formation .of .a .stem-loop .structure .in .the .RNA. .
b. .binding .of .Rho .protein .to .the .end .of .the .mRNA. .
c. .binding .of .a .sigma .(ζ) .factor .to .the .end .of .the .mRNA. .
d. .an .inverted .GC-rich .sequence .followed .by .seven .A .residues. .- .CORRECT
.ANSWER-d. .an .inverted .GC-rich .sequence .followed .by .seven .A .residues.
The .pioneering .studies .of .gene .regulation .in .E. .coli .were .conducted .in .the
.1950s .by:
a. .Miller .and .Urey. .
b. .Watson .and .Crick. .
c. .Jacob .and .Monod. .
d. .Lerner .and .Lowe. .- .CORRECT .ANSWER-c. .Jacob .and .Monod.
The .lac .operator .consists .of .approximately .20 .base .pairs .of .DNA .located:
, .a. .80-100 .base .pairs .upstream .of .the .transcription .initiation .site. .
b. .20-40 .base .pairs .upstream .of .the .transcription .initiation .site. .
c. .in .a .position .overlapping .the .initiation .site. .
d. .downstream .of .the .transcription .initiation .site. .- .CORRECT .ANSWER-c. .in .a
.position .overlapping .the .initiation .site.
Catabolite .repression .in .E. .coli:
a. .inhibits .the .breakdown .of .glucose .in .the .presence .of .lactose. .
b. .is .reversed .by .cAMP .binding .to .catabolite .activator .protein. .
c. .inhibits .the .lac .operon .unless .lactose .is .present. .
d. .is .a .negative .feedback .system. .- .CORRECT .ANSWER-b. .is .reversed .by .cAMP
.binding .to .catabolite .activator .protein.
Eukaryotic .RNA .polymerase .I .genes .code .for:
a. .mRNAs. .
b. .tRNAs. .
c. .small .nuclear .RNAs .and .small .cytoplasmic .RNAs. .
d. .ribosomal .RNAs. .- .CORRECT .ANSWER-d. .ribosomal .RNAs.
The .first .step .in .the .formation .of .a .transcription .complex .for .mRNA
.transcription .is .the .binding .of ._______ .to .the .TATA .box.
a. .TFIA .
b. .TFIIA .
c. .TFIIIA .
d. .TFIID .- .CORRECT .ANSWER-d. .TFIID
The .large .multi-subunit .complex .that .links .the .general .transcription .factors .to
.the .genespecific .transcription .factors .is .called:
a. .the .transcription .complex. .
b. .Mediator. .
c. .the .operator. .
d. .TBP. .- .CORRECT .ANSWER-b. .Mediator.
Release .of .RNA .polymerase .II .to .initiate .transcription .appears .to .be .the .direct
.result .of .the:
a. .binding .of .TAFs .to .the .polymerase. .
b. .unwinding .of .the .DNA .by .helicases. .
c. .phosphorylation .of .RNA .polymerase .by .a .protein .kinase. .
d. .removal .of .the .nucleosome .occupying .the .promoter .site. .- .CORRECT
.ANSWER-c. .phosphorylation .of .RNA .polymerase .by .a .protein .kinase.
A .major .difference .between .eukaryotic .and .prokaryotic .RNA .polymerases .is
.that .eukaryotic .polymerases:
a. .use .a .set .of .transcription .factors .to .bind .to .and .initiate .transcription.
b. .use .sigma .() .factors .to .initiate .transcription. .
c. .start .from .promoters. .
d. .start .from .origins .of .replication. .- .CORRECT .ANSWER-a. .use .a .set .of
.transcription .factors .to .bind .to .and .initiate .transcription.
