Robbins Basic Pathology
10th Edition
Author(s)Vinay Kumar; Abul K. Abbas;
Jon C. Aster
TEST BANK
Reference
Ch. 1 — The Genome
Question Stem
A 28-year-old woman has recurrent early-onset breast cancer;
genetic testing finds a truncating mutation that abolishes
BRCA1 protein function. Which cellular consequence best
explains her increased cancer risk?
Options
A. Increased error-prone replication by translesion polymerases
,B. Failure of homologous recombination DNA repair of double-
strand breaks
C. Global decrease in nucleotide excision repair of bulky
adducts
D. Loss of mismatch repair leading to microsatellite instability
Correct Answer
B
Rationales
• Correct (B): BRCA1 is crucial for homologous
recombination repair of double-strand DNA breaks; loss
leads to reliance on error-prone repair and genomic
instability, increasing cancer risk.
• Incorrect (A): Translesion synthesis is a bypass mechanism
unrelated to BRCA1’s principal role in double-strand break
repair.
• Incorrect (C): Nucleotide excision repair removes bulky
adducts (e.g., UV lesions) and is not the primary function
of BRCA1.
• Incorrect (D): Mismatch repair defects cause microsatellite
instability (e.g., Lynch syndrome), not BRCA1-associated
breast cancer.
Teaching Point
BRCA1 loss → defective homologous recombination → genomic
instability.
,Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
2
Reference
Ch. 1 — Cellular Housekeeping
Question Stem
A patient’s biopsy reveals abundant ubiquitin-tagged proteins in
hepatocytes and ballooning degeneration. Which defect most
likely produced this histologic pattern?
Options
A. Impaired proteasomal degradation of misfolded proteins
B. Failure of autophagosome formation and lysosome fusion
C. Defective chaperone-mediated import into mitochondria
D. Loss of endoplasmic reticulum-associated degradation
(ERAD) ubiquitination
Correct Answer
A
Rationales
• Correct (A): Accumulation of ubiquitin-tagged proteins
indicates proteasome dysfunction; inability to degrade
misfolded proteins causes cellular stress and degeneration.
• Incorrect (B): Autophagy defects lead to accumulation of
organelles and protein aggregates but would not explain
, ubiquitin tagging specifically targeted for proteasomal
degradation.
• Incorrect (C): Mitochondrial import defects cause
mitochondrial dysfunction rather than ubiquitin-tagged
cytosolic protein accumulation.
• Incorrect (D): ERAD requires ubiquitination, but presence
of ubiquitin-tagged proteins implies ubiquitination
occurred; the issue is downstream degradation
(proteasome), not ubiquitination itself.
Teaching Point
Ubiquitin tags mark proteins for proteasomal degradation;
proteasome failure causes toxic accumulation.
Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
3
Reference
Ch. 1 — Cellular Metabolism and Mitochondrial Function
Question Stem
A patient with ischemic myocardial injury shows early loss of
ATP, cell swelling, and plasma membrane blebs. Which
mitochondrial change best explains the immediate ATP
depletion?
10th Edition
Author(s)Vinay Kumar; Abul K. Abbas;
Jon C. Aster
TEST BANK
Reference
Ch. 1 — The Genome
Question Stem
A 28-year-old woman has recurrent early-onset breast cancer;
genetic testing finds a truncating mutation that abolishes
BRCA1 protein function. Which cellular consequence best
explains her increased cancer risk?
Options
A. Increased error-prone replication by translesion polymerases
,B. Failure of homologous recombination DNA repair of double-
strand breaks
C. Global decrease in nucleotide excision repair of bulky
adducts
D. Loss of mismatch repair leading to microsatellite instability
Correct Answer
B
Rationales
• Correct (B): BRCA1 is crucial for homologous
recombination repair of double-strand DNA breaks; loss
leads to reliance on error-prone repair and genomic
instability, increasing cancer risk.
• Incorrect (A): Translesion synthesis is a bypass mechanism
unrelated to BRCA1’s principal role in double-strand break
repair.
• Incorrect (C): Nucleotide excision repair removes bulky
adducts (e.g., UV lesions) and is not the primary function
of BRCA1.
• Incorrect (D): Mismatch repair defects cause microsatellite
instability (e.g., Lynch syndrome), not BRCA1-associated
breast cancer.
Teaching Point
BRCA1 loss → defective homologous recombination → genomic
instability.
,Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
2
Reference
Ch. 1 — Cellular Housekeeping
Question Stem
A patient’s biopsy reveals abundant ubiquitin-tagged proteins in
hepatocytes and ballooning degeneration. Which defect most
likely produced this histologic pattern?
Options
A. Impaired proteasomal degradation of misfolded proteins
B. Failure of autophagosome formation and lysosome fusion
C. Defective chaperone-mediated import into mitochondria
D. Loss of endoplasmic reticulum-associated degradation
(ERAD) ubiquitination
Correct Answer
A
Rationales
• Correct (A): Accumulation of ubiquitin-tagged proteins
indicates proteasome dysfunction; inability to degrade
misfolded proteins causes cellular stress and degeneration.
• Incorrect (B): Autophagy defects lead to accumulation of
organelles and protein aggregates but would not explain
, ubiquitin tagging specifically targeted for proteasomal
degradation.
• Incorrect (C): Mitochondrial import defects cause
mitochondrial dysfunction rather than ubiquitin-tagged
cytosolic protein accumulation.
• Incorrect (D): ERAD requires ubiquitination, but presence
of ubiquitin-tagged proteins implies ubiquitination
occurred; the issue is downstream degradation
(proteasome), not ubiquitination itself.
Teaching Point
Ubiquitin tags mark proteins for proteasomal degradation;
proteasome failure causes toxic accumulation.
Citation
Kumar et al. (2021). Robbins Basic Pathology (10th Ed.). Ch. 1.
3
Reference
Ch. 1 — Cellular Metabolism and Mitochondrial Function
Question Stem
A patient with ischemic myocardial injury shows early loss of
ATP, cell swelling, and plasma membrane blebs. Which
mitochondrial change best explains the immediate ATP
depletion?
