Portage Learning CHEM 210 Biochemistry
Module 8 Exam | Actual Transcription
Translation and Gene Regulation
Assessment with Answers
DOMAIN: TRANSCRIPTION: RNA SYNTHESIS (25%)
Q1. Which of the following enzymes is responsible for transcribing mRNA in
eukaryotes?
A. RNA polymerase I
B. RNA polymerase II
C. RNA polymerase III
D. RNA primase
Correct Answer: B
Rationale: B. [CORRECT] RNA polymerase II transcribes messenger RNA (mRNA) and
most small nuclear RNAs (snRNAs) in eukaryotes. It recognizes promoters containing
the TATA box and initiates transcription of protein-coding genes. A is incorrect; RNA
polymerase I transcribes ribosomal RNA (28S, 18S, and 5.8S rRNA) in the nucleolus. C is
incorrect; RNA polymerase III transcribes tRNA, 5S rRNA, and other small RNAs. D is
,incorrect; RNA primase is involved in DNA replication (synthesizing RNA primers), not
transcription.
Q2. The promoter region of a gene serves which function during transcription?
A. Encodes the amino acid sequence of the protein
B. Provides a binding site for RNA polymerase and transcription factors
C. Terminates transcription at the end of the gene
D. Splices introns from the pre-mRNA
Correct Answer: B
Rationale: B. [CORRECT] The promoter is a DNA sequence upstream of a gene that
provides a binding site for RNA polymerase and transcription factors, determining
where transcription initiates and which strand serves as the template. A is incorrect; the
coding region (exons) encodes the protein sequence. C is incorrect; termination signals
(rho-dependent or rho-independent in prokaryotes; polyadenylation signals in
eukaryotes) end transcription. D is incorrect; splicing occurs post-transcriptionally in the
nucleus.
Q3. Which of the following correctly describes the function of the sigma factor in
prokaryotic transcription?
A. It catalyzes the formation of phosphodiester bonds
B. It assists RNA polymerase in recognizing and binding to promoter sequences
C. It terminates transcription at rho-independent terminators
,D. It adds the 5' cap to mRNA
Correct Answer: B
Rationale: B. [CORRECT] In prokaryotes, the sigma factor associates with RNA
polymerase core enzyme (α₂ββ'ω) to form the holoenzyme and is responsible for
specific recognition of promoter sequences (-35 and -10 boxes). After initiation, sigma
factor dissociates. A is incorrect; the β subunit of RNA polymerase catalyzes
phosphodiester bond formation. C is incorrect; termination involves rho factor
(rho-dependent) or hairpin loops followed by U-rich regions (rho-independent). D is
incorrect; prokaryotes do not have 5' caps on their mRNA.
Q4. Rifampin, an antibiotic used to treat tuberculosis, inhibits which process?
A. DNA replication
B. Prokaryotic transcription by inhibiting RNA polymerase
C. Eukaryotic translation by binding to ribosomes
D. Peptidoglycan synthesis
Correct Answer: B
Rationale: B. [CORRECT] Rifampin inhibits prokaryotic RNA polymerase by binding to the
beta subunit, blocking transcription initiation by preventing the first phosphodiester
bond formation. It is bactericidal and highly effective against Mycobacterium
tuberculosis. A is incorrect; rifampin does not inhibit DNA replication (DNA
gyrase/topoisomerase IV are targets of fluoroquinolones). C is incorrect; rifampin
targets transcription, not translation (tetracyclines, macrolides target translation). D is
, incorrect; peptidoglycan synthesis is inhibited by beta-lactam antibiotics (penicillins,
cephalosporins) or vancomycin.
Q5. Which of the following best describes the difference between transcription initiation
in prokaryotes versus eukaryotes?
A. Prokaryotes require transcription factors; eukaryotes do not
B. Prokaryotes use a single RNA polymerase with sigma factors; eukaryotes use three
different RNA polymerases and general transcription factors
C. Prokaryotic transcription occurs in the nucleus; eukaryotic transcription occurs in the
cytoplasm
D. Prokaryotes add a 5' cap during initiation; eukaryotes do not
Correct Answer: B
Rationale: B. [CORRECT] Prokaryotes use a single RNA polymerase that associates with
sigma factors for promoter recognition. Eukaryotes use three distinct RNA polymerases
(I, II, III) and require general transcription factors (TFIIA, TFIIB, TFIID, etc.) to recruit RNA
polymerase II to promoters. A is incorrect; this reverses the requirement—eukaryotes
require numerous transcription factors. C is incorrect; prokaryotes lack a nucleus;
transcription occurs in the cytoplasm. D is incorrect; eukaryotes add 5' caps;
prokaryotes do not.
Q6. During transcription elongation, which of the following correctly describes the
direction of RNA synthesis and the template strand reading?
A. RNA is synthesized 3' to 5' while reading the template strand 5' to 3'
Module 8 Exam | Actual Transcription
Translation and Gene Regulation
Assessment with Answers
DOMAIN: TRANSCRIPTION: RNA SYNTHESIS (25%)
Q1. Which of the following enzymes is responsible for transcribing mRNA in
eukaryotes?
A. RNA polymerase I
B. RNA polymerase II
C. RNA polymerase III
D. RNA primase
Correct Answer: B
Rationale: B. [CORRECT] RNA polymerase II transcribes messenger RNA (mRNA) and
most small nuclear RNAs (snRNAs) in eukaryotes. It recognizes promoters containing
the TATA box and initiates transcription of protein-coding genes. A is incorrect; RNA
polymerase I transcribes ribosomal RNA (28S, 18S, and 5.8S rRNA) in the nucleolus. C is
incorrect; RNA polymerase III transcribes tRNA, 5S rRNA, and other small RNAs. D is
,incorrect; RNA primase is involved in DNA replication (synthesizing RNA primers), not
transcription.
Q2. The promoter region of a gene serves which function during transcription?
A. Encodes the amino acid sequence of the protein
B. Provides a binding site for RNA polymerase and transcription factors
C. Terminates transcription at the end of the gene
D. Splices introns from the pre-mRNA
Correct Answer: B
Rationale: B. [CORRECT] The promoter is a DNA sequence upstream of a gene that
provides a binding site for RNA polymerase and transcription factors, determining
where transcription initiates and which strand serves as the template. A is incorrect; the
coding region (exons) encodes the protein sequence. C is incorrect; termination signals
(rho-dependent or rho-independent in prokaryotes; polyadenylation signals in
eukaryotes) end transcription. D is incorrect; splicing occurs post-transcriptionally in the
nucleus.
Q3. Which of the following correctly describes the function of the sigma factor in
prokaryotic transcription?
A. It catalyzes the formation of phosphodiester bonds
B. It assists RNA polymerase in recognizing and binding to promoter sequences
C. It terminates transcription at rho-independent terminators
,D. It adds the 5' cap to mRNA
Correct Answer: B
Rationale: B. [CORRECT] In prokaryotes, the sigma factor associates with RNA
polymerase core enzyme (α₂ββ'ω) to form the holoenzyme and is responsible for
specific recognition of promoter sequences (-35 and -10 boxes). After initiation, sigma
factor dissociates. A is incorrect; the β subunit of RNA polymerase catalyzes
phosphodiester bond formation. C is incorrect; termination involves rho factor
(rho-dependent) or hairpin loops followed by U-rich regions (rho-independent). D is
incorrect; prokaryotes do not have 5' caps on their mRNA.
Q4. Rifampin, an antibiotic used to treat tuberculosis, inhibits which process?
A. DNA replication
B. Prokaryotic transcription by inhibiting RNA polymerase
C. Eukaryotic translation by binding to ribosomes
D. Peptidoglycan synthesis
Correct Answer: B
Rationale: B. [CORRECT] Rifampin inhibits prokaryotic RNA polymerase by binding to the
beta subunit, blocking transcription initiation by preventing the first phosphodiester
bond formation. It is bactericidal and highly effective against Mycobacterium
tuberculosis. A is incorrect; rifampin does not inhibit DNA replication (DNA
gyrase/topoisomerase IV are targets of fluoroquinolones). C is incorrect; rifampin
targets transcription, not translation (tetracyclines, macrolides target translation). D is
, incorrect; peptidoglycan synthesis is inhibited by beta-lactam antibiotics (penicillins,
cephalosporins) or vancomycin.
Q5. Which of the following best describes the difference between transcription initiation
in prokaryotes versus eukaryotes?
A. Prokaryotes require transcription factors; eukaryotes do not
B. Prokaryotes use a single RNA polymerase with sigma factors; eukaryotes use three
different RNA polymerases and general transcription factors
C. Prokaryotic transcription occurs in the nucleus; eukaryotic transcription occurs in the
cytoplasm
D. Prokaryotes add a 5' cap during initiation; eukaryotes do not
Correct Answer: B
Rationale: B. [CORRECT] Prokaryotes use a single RNA polymerase that associates with
sigma factors for promoter recognition. Eukaryotes use three distinct RNA polymerases
(I, II, III) and require general transcription factors (TFIIA, TFIIB, TFIID, etc.) to recruit RNA
polymerase II to promoters. A is incorrect; this reverses the requirement—eukaryotes
require numerous transcription factors. C is incorrect; prokaryotes lack a nucleus;
transcription occurs in the cytoplasm. D is incorrect; eukaryotes add 5' caps;
prokaryotes do not.
Q6. During transcription elongation, which of the following correctly describes the
direction of RNA synthesis and the template strand reading?
A. RNA is synthesized 3' to 5' while reading the template strand 5' to 3'
