Robbins Basic Pathology
10th Edition
Author(s)Vinay Kumar; Abul K. Abbas;
Jon C. Aster
TEST BANK
1)
Reference
Ch. 1 — The Cell as a Unit of Health and Disease — The
Genome
Question Stem
A 35-year-old man presents with recurrent early-onset colon
polyps. Genetic testing finds a heterozygous nonsense mutation
in a DNA mismatch-repair gene. Which cellular consequence
best explains his increased cancer risk?
,Options
A. Increased rate of double-strand DNA breaks due to defective
homologous recombination
B. Accumulation of replication errors leading to microsatellite
instability and mutator phenotype
C. Loss of mitochondrial DNA repair causing oxidative
phosphorylation failure
D. Global loss of DNA methylation resulting in immediate
oncogene silencing
Correct Answer
B
Rationales
Correct: Defective mismatch repair allows replication errors to
persist, producing microsatellite instability and a mutator
phenotype that accelerates oncogenic mutations.
A: Homologous recombination defects (e.g., BRCA) cause
double-strand break repair failure, not mismatch repair
mutations.
C: Mismatch-repair genes do not primarily affect mitochondrial
DNA or oxidative phosphorylation.
D: Global hypomethylation can activate oncogenes, not silence
them, and is not the direct result of mismatch-repair deficiency.
Teaching Point
Mismatch-repair defects → replication errors → microsatellite
instability → cancer risk.
,Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
2)
Reference
Ch. 1 — The Cell as a Unit of Health and Disease — The
Genome
Question Stem
A newborn has a metabolic disorder from a mutation that
changes a single amino acid (missense). Which mechanism
most likely explains how a missense mutation can produce a
dysfunctional enzyme despite near-normal protein expression?
Options
A. Missense mutations typically cause immediate nonsense-
mediated mRNA decay.
B. Altered amino acid disrupts protein folding or active site,
impairing function.
C. Missense variants always abolish transcription of the gene.
D. A single amino acid change increases rates of chromosomal
non-disjunction.
Correct Answer
B
Rationales
Correct: Missense mutations substitute one amino acid, which
can disrupt folding or the catalytic/active site, producing a
, dysfunctional enzyme even when protein is produced.
A: Nonsense-mediated decay affects premature stop codons,
not missense changes.
C: Missense mutations do not typically abolish transcription.
D: Chromosomal non-disjunction is unrelated to single-amino-
acid substitutions.
Teaching Point
Missense mutations → altered amino acid → disrupted
structure/function of proteins.
Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
3)
Reference
Ch. 1 — The Cell as a Unit of Health and Disease — Cellular
Housekeeping
Question Stem
A patient’s biopsy shows accumulation of ubiquitin-tagged
inclusions in neurons with impaired proteasome function.
Which downstream cellular process most likely contributes to
neuronal death?
Options
A. Enhanced autophagy that clears aggregates and preserves
cell viability
B. Accumulation of misfolded proteins triggering ER stress and
10th Edition
Author(s)Vinay Kumar; Abul K. Abbas;
Jon C. Aster
TEST BANK
1)
Reference
Ch. 1 — The Cell as a Unit of Health and Disease — The
Genome
Question Stem
A 35-year-old man presents with recurrent early-onset colon
polyps. Genetic testing finds a heterozygous nonsense mutation
in a DNA mismatch-repair gene. Which cellular consequence
best explains his increased cancer risk?
,Options
A. Increased rate of double-strand DNA breaks due to defective
homologous recombination
B. Accumulation of replication errors leading to microsatellite
instability and mutator phenotype
C. Loss of mitochondrial DNA repair causing oxidative
phosphorylation failure
D. Global loss of DNA methylation resulting in immediate
oncogene silencing
Correct Answer
B
Rationales
Correct: Defective mismatch repair allows replication errors to
persist, producing microsatellite instability and a mutator
phenotype that accelerates oncogenic mutations.
A: Homologous recombination defects (e.g., BRCA) cause
double-strand break repair failure, not mismatch repair
mutations.
C: Mismatch-repair genes do not primarily affect mitochondrial
DNA or oxidative phosphorylation.
D: Global hypomethylation can activate oncogenes, not silence
them, and is not the direct result of mismatch-repair deficiency.
Teaching Point
Mismatch-repair defects → replication errors → microsatellite
instability → cancer risk.
,Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
2)
Reference
Ch. 1 — The Cell as a Unit of Health and Disease — The
Genome
Question Stem
A newborn has a metabolic disorder from a mutation that
changes a single amino acid (missense). Which mechanism
most likely explains how a missense mutation can produce a
dysfunctional enzyme despite near-normal protein expression?
Options
A. Missense mutations typically cause immediate nonsense-
mediated mRNA decay.
B. Altered amino acid disrupts protein folding or active site,
impairing function.
C. Missense variants always abolish transcription of the gene.
D. A single amino acid change increases rates of chromosomal
non-disjunction.
Correct Answer
B
Rationales
Correct: Missense mutations substitute one amino acid, which
can disrupt folding or the catalytic/active site, producing a
, dysfunctional enzyme even when protein is produced.
A: Nonsense-mediated decay affects premature stop codons,
not missense changes.
C: Missense mutations do not typically abolish transcription.
D: Chromosomal non-disjunction is unrelated to single-amino-
acid substitutions.
Teaching Point
Missense mutations → altered amino acid → disrupted
structure/function of proteins.
Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
3)
Reference
Ch. 1 — The Cell as a Unit of Health and Disease — Cellular
Housekeeping
Question Stem
A patient’s biopsy shows accumulation of ubiquitin-tagged
inclusions in neurons with impaired proteasome function.
Which downstream cellular process most likely contributes to
neuronal death?
Options
A. Enhanced autophagy that clears aggregates and preserves
cell viability
B. Accumulation of misfolded proteins triggering ER stress and
