BIOLOGY 251 EXAM 1 | QUESTIONS
AND ANSWERS | 2026 REVISED
UPDATE | 100% CORRECT -WSU.
110 Questions with Answers and Detailed Rationales
100 PERCENT GUARANTEED PASS
INSTANT DOWNLOAD ANSWERS INCLUDED
IMPORTANCE OF THIS DOCUMENT
This comprehensive examination preparation guide has been meticulously developed to help you succeed in the
BIOLOGY 251 EXAM 1 | QUESTIONS AND ANSWERS | 2026 REVISED UPDATE | 100% CORRECT -WSU.. It
contains 110 carefully selected questions that reflect the most current exam content and testing strategies. Each
question is accompanied by a correct answer and a detailed rationale that explains the underlying
pathophysiology, pharmacology, or clinical reasoning.
Self-Assessment – Test your knowledge and Exam Preparation – Familiarize yourself with the
identify areas requiring further question format and content
study areas
Concept Reinforcement – Deepen your Confidence Building – Develop test-taking
understanding through strategies and reduce
evidence-based exam anxiety
rationales
Time Management – Practice answering
questions under simulated
exam conditions
Review Summary 110 Questions
Foundations - Application - Biology 251 1 AND 2026 Revised Update 100 Correct -wsu Biology 251
Molecular AND Cellular Biology Undergraduate YEAR 3 / Graduate
All answers with rationales
,Table of Contents
Content Area Questions Key Topics
CELL Biology AND 1-19 Mutation, Protein, Likely, Transcription, Subunit
Membrane Transport
Cellular Respiration AND 20-38 Likely, Mutation, Protein, Transcription, Allele
Metabolism
Photosynthesis 39-57 Experimental, Directly, Immediate, Researcher, Cells
CELL Division Mitosis AND 58-76 Likely, Glucose, Researcher, Eukaryotic, Operon
Meiosis
Genetics AND Inheritance 77-95 Mutation, Mitochondrial, Membrane, Researcher, Directly
DNA Structure AND 96-110 Researcher, Process, Cells, Signaling, Population
Replication
TOTAL 110 All questions include answers and detailed rationales
,Section A - CELL Biology AND Membrane Transport
Q1.
In a genome-wide CRISPR screen, you identify a gene whose loss confers resistance to a
drug that stabilizes p53. Which of the following is the most likely function of the gene
product?
A. E3 ubiquitin ligase that targets p53 for B. Transcriptional coactivator of p53 target
degradation genes
C. Kinase that phosphorylates p53 at Ser15 D. Acetyltransferase that enhances p53
DNA binding
Correct: A - E3 ubiquitin ligase that targets p53 for degradation
Rationale:Loss of an E3 ligase that degrades p53 would stabilize p53, making cells resistant
to a p53-stabilizing drug. Other options would enhance p53 activity, not confer resistance.
Q2.
A bacterial two-hybrid assay reveals that a candidate transcription factor interacts with the
RNA polymerase subunit. Which domain of the transcription factor is most likely
responsible for this interaction?
A. DNA-binding domain B. Activation domain
C. Dimerization domain D. Ligand-binding domain
Correct: B - Activation domain
Rationale:Activation domains often contact general transcription factors like RNA polymerase
subunits to stimulate transcription. DNA-binding domains bind DNA, not polymerase.
Dimerization and ligand-binding domains have other roles.
Q3.
In a kinetic study of an enzyme, the Lineweaver-Burk plot shows lines intersecting on the
1/V axis. Which of the following is true?
A. The inhibitor is competitive B. The inhibitor is uncompetitive
C. The inhibitor is noncompetitive D. The enzyme follows Michaelis-Menten
kinetics
Correct: C - The inhibitor is noncompetitive
Page 3
, Section A - CELL Biology AND Membrane Transport
Rationale: Intersection on the 1/V axis indicates that Vmax is unchanged but Km increases,
characteristic of competitive inhibition. Uncompetitive and noncompetitive inhibitors change
Vmax. Michaelis-Menten kinetics is assumed but not proven by the plot alone.
Q4.
A patient with a mitochondrial disorder has a mutation in a gene encoding a component of
the pyruvate dehydrogenase complex. Which of the following metabolic consequences is
most expected?
A. Increased lactate production B. Increased acetyl-CoA production
C. Decreased glycolysis D. Decreased fatty acid oxidation
Correct: A - Increased lactate production
Rationale:PDH deficiency impairs conversion of pyruvate to acetyl-CoA, shunting pyruvate to
lactate. Acetyl-CoA production decreases, glycolysis is not directly decreased, and fatty acid
oxidation is not directly affected.
Q5.
In a fluorescence recovery after photobleaching (FRAP) experiment, a membrane protein
shows rapid recovery in one region but slow recovery in another. Which of the following
best explains this observation?
A. The protein is anchored to the B. The protein is in a lipid raft in the fast
cytoskeleton in the slow region region
C. The protein is denatured in the slow D. The protein is covalently linked to the
region extracellular matrix in the fast region
Correct: A - The protein is anchored to the cytoskeleton in the slow region
Rationale:Cytoskeletal anchoring restricts lateral mobility, leading to slow FRAP recovery.
Lipid rafts typically slow diffusion, not speed it. Denaturation and ECM linkage would also
slow recovery, not cause regional differences.
Q6.
A researcher treats cells with a drug that inhibits the proteasome. Which of the following
immediate effects is most likely?
A. Accumulation of polyubiquitinated B. Decreased ubiquitin conjugation
proteins
C. Increased protein synthesis D. Enhanced autophagy of misfolded
proteins
Correct: A - Accumulation of polyubiquitinated proteins
Page 4
AND ANSWERS | 2026 REVISED
UPDATE | 100% CORRECT -WSU.
110 Questions with Answers and Detailed Rationales
100 PERCENT GUARANTEED PASS
INSTANT DOWNLOAD ANSWERS INCLUDED
IMPORTANCE OF THIS DOCUMENT
This comprehensive examination preparation guide has been meticulously developed to help you succeed in the
BIOLOGY 251 EXAM 1 | QUESTIONS AND ANSWERS | 2026 REVISED UPDATE | 100% CORRECT -WSU.. It
contains 110 carefully selected questions that reflect the most current exam content and testing strategies. Each
question is accompanied by a correct answer and a detailed rationale that explains the underlying
pathophysiology, pharmacology, or clinical reasoning.
Self-Assessment – Test your knowledge and Exam Preparation – Familiarize yourself with the
identify areas requiring further question format and content
study areas
Concept Reinforcement – Deepen your Confidence Building – Develop test-taking
understanding through strategies and reduce
evidence-based exam anxiety
rationales
Time Management – Practice answering
questions under simulated
exam conditions
Review Summary 110 Questions
Foundations - Application - Biology 251 1 AND 2026 Revised Update 100 Correct -wsu Biology 251
Molecular AND Cellular Biology Undergraduate YEAR 3 / Graduate
All answers with rationales
,Table of Contents
Content Area Questions Key Topics
CELL Biology AND 1-19 Mutation, Protein, Likely, Transcription, Subunit
Membrane Transport
Cellular Respiration AND 20-38 Likely, Mutation, Protein, Transcription, Allele
Metabolism
Photosynthesis 39-57 Experimental, Directly, Immediate, Researcher, Cells
CELL Division Mitosis AND 58-76 Likely, Glucose, Researcher, Eukaryotic, Operon
Meiosis
Genetics AND Inheritance 77-95 Mutation, Mitochondrial, Membrane, Researcher, Directly
DNA Structure AND 96-110 Researcher, Process, Cells, Signaling, Population
Replication
TOTAL 110 All questions include answers and detailed rationales
,Section A - CELL Biology AND Membrane Transport
Q1.
In a genome-wide CRISPR screen, you identify a gene whose loss confers resistance to a
drug that stabilizes p53. Which of the following is the most likely function of the gene
product?
A. E3 ubiquitin ligase that targets p53 for B. Transcriptional coactivator of p53 target
degradation genes
C. Kinase that phosphorylates p53 at Ser15 D. Acetyltransferase that enhances p53
DNA binding
Correct: A - E3 ubiquitin ligase that targets p53 for degradation
Rationale:Loss of an E3 ligase that degrades p53 would stabilize p53, making cells resistant
to a p53-stabilizing drug. Other options would enhance p53 activity, not confer resistance.
Q2.
A bacterial two-hybrid assay reveals that a candidate transcription factor interacts with the
RNA polymerase subunit. Which domain of the transcription factor is most likely
responsible for this interaction?
A. DNA-binding domain B. Activation domain
C. Dimerization domain D. Ligand-binding domain
Correct: B - Activation domain
Rationale:Activation domains often contact general transcription factors like RNA polymerase
subunits to stimulate transcription. DNA-binding domains bind DNA, not polymerase.
Dimerization and ligand-binding domains have other roles.
Q3.
In a kinetic study of an enzyme, the Lineweaver-Burk plot shows lines intersecting on the
1/V axis. Which of the following is true?
A. The inhibitor is competitive B. The inhibitor is uncompetitive
C. The inhibitor is noncompetitive D. The enzyme follows Michaelis-Menten
kinetics
Correct: C - The inhibitor is noncompetitive
Page 3
, Section A - CELL Biology AND Membrane Transport
Rationale: Intersection on the 1/V axis indicates that Vmax is unchanged but Km increases,
characteristic of competitive inhibition. Uncompetitive and noncompetitive inhibitors change
Vmax. Michaelis-Menten kinetics is assumed but not proven by the plot alone.
Q4.
A patient with a mitochondrial disorder has a mutation in a gene encoding a component of
the pyruvate dehydrogenase complex. Which of the following metabolic consequences is
most expected?
A. Increased lactate production B. Increased acetyl-CoA production
C. Decreased glycolysis D. Decreased fatty acid oxidation
Correct: A - Increased lactate production
Rationale:PDH deficiency impairs conversion of pyruvate to acetyl-CoA, shunting pyruvate to
lactate. Acetyl-CoA production decreases, glycolysis is not directly decreased, and fatty acid
oxidation is not directly affected.
Q5.
In a fluorescence recovery after photobleaching (FRAP) experiment, a membrane protein
shows rapid recovery in one region but slow recovery in another. Which of the following
best explains this observation?
A. The protein is anchored to the B. The protein is in a lipid raft in the fast
cytoskeleton in the slow region region
C. The protein is denatured in the slow D. The protein is covalently linked to the
region extracellular matrix in the fast region
Correct: A - The protein is anchored to the cytoskeleton in the slow region
Rationale:Cytoskeletal anchoring restricts lateral mobility, leading to slow FRAP recovery.
Lipid rafts typically slow diffusion, not speed it. Denaturation and ECM linkage would also
slow recovery, not cause regional differences.
Q6.
A researcher treats cells with a drug that inhibits the proteasome. Which of the following
immediate effects is most likely?
A. Accumulation of polyubiquitinated B. Decreased ubiquitin conjugation
proteins
C. Increased protein synthesis D. Enhanced autophagy of misfolded
proteins
Correct: A - Accumulation of polyubiquitinated proteins
Page 4
