PASSPOINT PRO SOUTHEASTERN LOUISIANA UNIVERSITY
GBIO 200
CELL BIOLOGY
EXAM 2 - 125Q
Gene regulation, transcription, RNA processing, translation, mutations,
protein quality control, and intracellular trafficking
125 A-D FULL
ORIGINAL QUESTIONS ANSWER CHOICES RATIONALES
Built for focused exam review
Concept recall + application questions
Immediate answers with concise explanations
Compact layout for fast review and printing
Original practice content aligned to GBIO 200 topics
PassPoint Pro | Practice. Understand. Perform. GBIO 200
,PASSPOINT PRO | GBIO 200 CELL BIOLOGY EXAM 2 - 125Q
HOW TO USE THIS PRACTICE SET
Format: Each item includes four answer choices followed immediately by the correct answer and an explanation. Best use:
Complete a first pass without reading the answer, then use each rationale to repair weak concepts. Coverage: Gene regulation,
transcription, RNA processing, translation, mutations, protein quality control, and intracellular trafficking.
QUESTIONS 1-25
1 Which term or structure best matches the following description: a stretch of adenines added to the
3-prime end of most eukaryotic mRNAs that enhances stability and translation?
A. poly-A tail
B. RNA splicing
C. 5-prime cap
D. alternative splicing
Answer: A
Explanation: Poly-a tail is correct because it is a stretch of adenines added to the 3-prime end of most eukaryotic mRNAs that enhances
stability and translation. A mature mRNA carries a long adenine-rich extension at its 3-prime end. This match is more specific than the
related alternatives, which describe different structures, molecules, or processes.
2 A student is reviewing rRNA. Which description is most accurate?
A. flexible base pairing at the third codon position that allows some tRNAs to recognize more than one codon
B. a three-nucleotide sequence in mRNA that specifies an amino acid or translation stop signal
C. the ribosomal site that holds the tRNA carrying the growing polypeptide chain
D. ribosomal RNA that forms the structural and catalytic core of ribosomes
Answer: D
Explanation: The correct description of rRNA is that it is ribosomal RNA that forms the structural and catalytic core of ribosomes. RNA
within the large ribosomal subunit catalyzes peptide bond formation. The other choices define different concepts and therefore do not fit
this term.
3 RNA polymerase II and general transcription factors gather near a gene's transcription start site. What is
the best explanation for the finding?
A. alternative splicing
B. constitutive secretion
C. 5-prime cap
D. promoter
Answer: D
Explanation: Promoter best explains the observation because it is a DNA region where general transcription machinery assembles to
initiate transcription of a gene. The scenario is a direct application of that function or mechanism. The distractors are related cell-biology
concepts but do not account for the key feature described.
Original practice questions with explanations Page 2
,PASSPOINT PRO | GBIO 200 CELL BIOLOGY EXAM 2 - 125Q
4 A cell undergoes the following change: Loss of a specific species would impair incorporation of its
corresponding amino acid at matching codons. Which target was most likely altered?
A. anticodon
B. polysome
C. tRNA
D. mRNA
Answer: C
Explanation: Trna is the best match. It is an adaptor RNA that pairs an anticodon with an mRNA codon and delivers the corresponding
amino acid to the ribosome, so the stated consequence follows directly when its function is changed. The other options can influence
cellular behavior, but they do not most directly predict this specific outcome.
5 Which term-description pairing is correct?
A. tRNA - a three-nucleotide sequence in tRNA that base-pairs with a complementary mRNA codon
B. anticodon - a three-nucleotide sequence in mRNA that specifies an amino acid or translation stop signal
C. codon - an adaptor RNA that pairs an anticodon with an mRNA codon and delivers the corresponding amino acid to the ribosome
D. E site - the ribosomal site through which a deacylated tRNA exits after donating its amino acid
Answer: D
Explanation: The correct pairing is E site with its defining feature: the ribosomal site through which a deacylated tRNA exits after donating
its amino acid. An empty tRNA leaves the ribosome after its role in elongation is complete. The remaining pairs intentionally mismatch a
term with the description of a different concept.
6 Which option is most accurately defined as an amino-acid sequence recognized by import machinery to
direct proteins through nuclear pores into the nucleus?
A. COPI-coated vesicle
B. clathrin-coated vesicle
C. nuclear localization signal
D. signal peptide
Answer: C
Explanation: Nuclear localization signal is correct because it is an amino-acid sequence recognized by import machinery to direct
proteins through nuclear pores into the nucleus. A transcription factor synthesized in the cytosol enters the nucleus because it carries a
short basic targeting sequence. This match is more specific than the related alternatives, which describe different structures, molecules, or
processes.
7 Which statement best describes A site?
A. multiple ribosomes translating the same mRNA simultaneously
B. the ribosomal site that accepts the incoming aminoacyl-tRNA during elongation
C. messenger RNA that carries coding information from DNA to ribosomes
D. an adaptor RNA that pairs an anticodon with an mRNA codon and delivers the corresponding amino acid to the ribosome
Answer: B
Explanation: The correct description of A site is that it is the ribosomal site that accepts the incoming aminoacyl-tRNA during elongation.
A charged tRNA first enters the ribosome at the position matching the next codon. The other choices define different concepts and
therefore do not fit this term.
Original practice questions with explanations Page 3
, PASSPOINT PRO | GBIO 200 CELL BIOLOGY EXAM 2 - 125Q
8 The tRNA attached to the nascent peptide occupies the central ribosomal binding site. Which structure
or process is most directly involved?
A. anticodon
B. A site
C. P site
D. mRNA
Answer: C
Explanation: P site best explains the observation because it is the ribosomal site that holds the tRNA carrying the growing polypeptide
chain. The scenario is a direct application of that function or mechanism. The distractors are related cell-biology concepts but do not
account for the key feature described.
9 A selective perturbation causes this outcome: Disrupting coat assembly would impair many endocytic
events. Which process or structure is the best match?
A. mannose-6-phosphate tag
B. regulated secretion
C. signal peptide
D. clathrin-coated vesicle
Answer: D
Explanation: Clathrin-coated vesicle is the best match. It is a coated vesicle used in receptor-mediated endocytosis and selected
transport from the trans-Golgi network, so the stated consequence follows directly when its function is changed. The other options can
influence cellular behavior, but they do not most directly predict this specific outcome.
10 Which term-description pairing is correct?
A. nucleosome - the ribosomal site that holds the tRNA carrying the growing polypeptide chain
B. P site - flexible base pairing at the third codon position that allows some tRNAs to recognize more than one codon
C. wobble pairing - the basic chromatin unit in which DNA wraps around a histone protein core
D. enhancer - a regulatory DNA sequence that can bind activators and increase transcription, often from a distance
Answer: D
Explanation: The correct pairing is enhancer with its defining feature: a regulatory DNA sequence that can bind activators and increase
transcription, often from a distance. A regulatory sequence thousands of bases from a promoter loops toward the transcription machinery
and boosts expression. The remaining pairs intentionally mismatch a term with the description of a different concept.
11 Identify the concept described here: a nucleotide change that alters a codon so a different amino acid is
inserted.
A. 5-prime cap
B. chromatin
C. missense mutation
D. molecular chaperone
Answer: C
Explanation: Missense mutation is correct because it is a nucleotide change that alters a codon so a different amino acid is inserted. A
point mutation changes a protein sequence at one amino acid position without shortening the chain. This match is more specific than the
related alternatives, which describe different structures, molecules, or processes.
Original practice questions with explanations Page 4
GBIO 200
CELL BIOLOGY
EXAM 2 - 125Q
Gene regulation, transcription, RNA processing, translation, mutations,
protein quality control, and intracellular trafficking
125 A-D FULL
ORIGINAL QUESTIONS ANSWER CHOICES RATIONALES
Built for focused exam review
Concept recall + application questions
Immediate answers with concise explanations
Compact layout for fast review and printing
Original practice content aligned to GBIO 200 topics
PassPoint Pro | Practice. Understand. Perform. GBIO 200
,PASSPOINT PRO | GBIO 200 CELL BIOLOGY EXAM 2 - 125Q
HOW TO USE THIS PRACTICE SET
Format: Each item includes four answer choices followed immediately by the correct answer and an explanation. Best use:
Complete a first pass without reading the answer, then use each rationale to repair weak concepts. Coverage: Gene regulation,
transcription, RNA processing, translation, mutations, protein quality control, and intracellular trafficking.
QUESTIONS 1-25
1 Which term or structure best matches the following description: a stretch of adenines added to the
3-prime end of most eukaryotic mRNAs that enhances stability and translation?
A. poly-A tail
B. RNA splicing
C. 5-prime cap
D. alternative splicing
Answer: A
Explanation: Poly-a tail is correct because it is a stretch of adenines added to the 3-prime end of most eukaryotic mRNAs that enhances
stability and translation. A mature mRNA carries a long adenine-rich extension at its 3-prime end. This match is more specific than the
related alternatives, which describe different structures, molecules, or processes.
2 A student is reviewing rRNA. Which description is most accurate?
A. flexible base pairing at the third codon position that allows some tRNAs to recognize more than one codon
B. a three-nucleotide sequence in mRNA that specifies an amino acid or translation stop signal
C. the ribosomal site that holds the tRNA carrying the growing polypeptide chain
D. ribosomal RNA that forms the structural and catalytic core of ribosomes
Answer: D
Explanation: The correct description of rRNA is that it is ribosomal RNA that forms the structural and catalytic core of ribosomes. RNA
within the large ribosomal subunit catalyzes peptide bond formation. The other choices define different concepts and therefore do not fit
this term.
3 RNA polymerase II and general transcription factors gather near a gene's transcription start site. What is
the best explanation for the finding?
A. alternative splicing
B. constitutive secretion
C. 5-prime cap
D. promoter
Answer: D
Explanation: Promoter best explains the observation because it is a DNA region where general transcription machinery assembles to
initiate transcription of a gene. The scenario is a direct application of that function or mechanism. The distractors are related cell-biology
concepts but do not account for the key feature described.
Original practice questions with explanations Page 2
,PASSPOINT PRO | GBIO 200 CELL BIOLOGY EXAM 2 - 125Q
4 A cell undergoes the following change: Loss of a specific species would impair incorporation of its
corresponding amino acid at matching codons. Which target was most likely altered?
A. anticodon
B. polysome
C. tRNA
D. mRNA
Answer: C
Explanation: Trna is the best match. It is an adaptor RNA that pairs an anticodon with an mRNA codon and delivers the corresponding
amino acid to the ribosome, so the stated consequence follows directly when its function is changed. The other options can influence
cellular behavior, but they do not most directly predict this specific outcome.
5 Which term-description pairing is correct?
A. tRNA - a three-nucleotide sequence in tRNA that base-pairs with a complementary mRNA codon
B. anticodon - a three-nucleotide sequence in mRNA that specifies an amino acid or translation stop signal
C. codon - an adaptor RNA that pairs an anticodon with an mRNA codon and delivers the corresponding amino acid to the ribosome
D. E site - the ribosomal site through which a deacylated tRNA exits after donating its amino acid
Answer: D
Explanation: The correct pairing is E site with its defining feature: the ribosomal site through which a deacylated tRNA exits after donating
its amino acid. An empty tRNA leaves the ribosome after its role in elongation is complete. The remaining pairs intentionally mismatch a
term with the description of a different concept.
6 Which option is most accurately defined as an amino-acid sequence recognized by import machinery to
direct proteins through nuclear pores into the nucleus?
A. COPI-coated vesicle
B. clathrin-coated vesicle
C. nuclear localization signal
D. signal peptide
Answer: C
Explanation: Nuclear localization signal is correct because it is an amino-acid sequence recognized by import machinery to direct
proteins through nuclear pores into the nucleus. A transcription factor synthesized in the cytosol enters the nucleus because it carries a
short basic targeting sequence. This match is more specific than the related alternatives, which describe different structures, molecules, or
processes.
7 Which statement best describes A site?
A. multiple ribosomes translating the same mRNA simultaneously
B. the ribosomal site that accepts the incoming aminoacyl-tRNA during elongation
C. messenger RNA that carries coding information from DNA to ribosomes
D. an adaptor RNA that pairs an anticodon with an mRNA codon and delivers the corresponding amino acid to the ribosome
Answer: B
Explanation: The correct description of A site is that it is the ribosomal site that accepts the incoming aminoacyl-tRNA during elongation.
A charged tRNA first enters the ribosome at the position matching the next codon. The other choices define different concepts and
therefore do not fit this term.
Original practice questions with explanations Page 3
, PASSPOINT PRO | GBIO 200 CELL BIOLOGY EXAM 2 - 125Q
8 The tRNA attached to the nascent peptide occupies the central ribosomal binding site. Which structure
or process is most directly involved?
A. anticodon
B. A site
C. P site
D. mRNA
Answer: C
Explanation: P site best explains the observation because it is the ribosomal site that holds the tRNA carrying the growing polypeptide
chain. The scenario is a direct application of that function or mechanism. The distractors are related cell-biology concepts but do not
account for the key feature described.
9 A selective perturbation causes this outcome: Disrupting coat assembly would impair many endocytic
events. Which process or structure is the best match?
A. mannose-6-phosphate tag
B. regulated secretion
C. signal peptide
D. clathrin-coated vesicle
Answer: D
Explanation: Clathrin-coated vesicle is the best match. It is a coated vesicle used in receptor-mediated endocytosis and selected
transport from the trans-Golgi network, so the stated consequence follows directly when its function is changed. The other options can
influence cellular behavior, but they do not most directly predict this specific outcome.
10 Which term-description pairing is correct?
A. nucleosome - the ribosomal site that holds the tRNA carrying the growing polypeptide chain
B. P site - flexible base pairing at the third codon position that allows some tRNAs to recognize more than one codon
C. wobble pairing - the basic chromatin unit in which DNA wraps around a histone protein core
D. enhancer - a regulatory DNA sequence that can bind activators and increase transcription, often from a distance
Answer: D
Explanation: The correct pairing is enhancer with its defining feature: a regulatory DNA sequence that can bind activators and increase
transcription, often from a distance. A regulatory sequence thousands of bases from a promoter loops toward the transcription machinery
and boosts expression. The remaining pairs intentionally mismatch a term with the description of a different concept.
11 Identify the concept described here: a nucleotide change that alters a codon so a different amino acid is
inserted.
A. 5-prime cap
B. chromatin
C. missense mutation
D. molecular chaperone
Answer: C
Explanation: Missense mutation is correct because it is a nucleotide change that alters a codon so a different amino acid is inserted. A
point mutation changes a protein sequence at one amino acid position without shortening the chain. This match is more specific than the
related alternatives, which describe different structures, molecules, or processes.
Original practice questions with explanations Page 4
