McCance & Huether’s Pathophysiology
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A microbiology researcher exposes two cell
populations to an antibiotic that selectively inhibits 70S
ribosomes. One population rapidly loses protein synthesis,
, whereas the other remains largely unaffected. This
difference most directly reflects which structural
distinction?
A. Presence of membrane-bound nuclei
B. Presence of cytoplasmic microtubules
C. Presence of peptidoglycan-containing plasma
membranes
D. Presence of membrane-bound mitochondria
Correct Answer: A
Rationale:
• Clinical Clue: Selective effect on 70S ribosomes.
• Mechanism: Prokaryotes contain 70S ribosomes and lack
membrane-bound nuclei; eukaryotic cytoplasmic
ribosomes are 80S.
• Why the Correct Answer Is Right: Lack of a membrane-
bound nucleus is a defining prokaryotic feature associated
with 70S ribosomes.
• Why the Other Options Are Wrong:
o B: Microtubules are eukaryotic but not the primary
explanation.
o C: Peptidoglycan is found in cell walls, not plasma
membranes.
o D: Mitochondria distinguish eukaryotes but do not
directly explain ribosomal susceptibility.
,• Exam Trap: Confusing ribosomal differences with
organelle differences alone.
• High-Yield Clinical Correlation: Many antibiotics target
bacterial ribosomes.
• Memory Anchor: Prokaryote = no nucleus + 70S.
Q2. A child develops recurrent respiratory infections due
to impaired ciliary motion in airway epithelial cells. The
underlying defect most likely involves disruption of which
cellular structure?
A. Intermediate filaments
B. Actin microfilaments
C. Microtubules
D. Gap junctions
Correct Answer: C
Rationale:
• Clinical Clue: Defective ciliary movement.
• Mechanism: Cilia rely on microtubules arranged in a 9+2
axonemal pattern with dynein-mediated motion.
• Why the Correct Answer Is Right: Microtubules form the
structural basis of motile cilia.
• Why the Other Options Are Wrong:
o A: Intermediate filaments provide tensile support.
, o B: Actin supports cell shape and contraction but not
ciliary axonemes.
o D: Gap junctions mediate communication.
• Exam Trap: Choosing actin because it mediates movement
in other contexts.
• High-Yield Clinical Correlation: Primary ciliary dyskinesia
causes recurrent infections and infertility.
• Memory Anchor: Cilia ride on microtubule rails.
Q3. A patient with severe alcohol-associated liver injury
demonstrates impaired detoxification of drugs and toxins.
Damage to which organelle best accounts for this
functional decline?
A. Golgi apparatus
B. Rough endoplasmic reticulum
C. Lysosome
D. Smooth endoplasmic reticulum
Correct Answer: D
Rationale:
• Clinical Clue: Impaired detoxification.
• Mechanism: Smooth endoplasmic reticulum contains
enzymes involved in lipid metabolism and xenobiotic
detoxification.
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A microbiology researcher exposes two cell
populations to an antibiotic that selectively inhibits 70S
ribosomes. One population rapidly loses protein synthesis,
, whereas the other remains largely unaffected. This
difference most directly reflects which structural
distinction?
A. Presence of membrane-bound nuclei
B. Presence of cytoplasmic microtubules
C. Presence of peptidoglycan-containing plasma
membranes
D. Presence of membrane-bound mitochondria
Correct Answer: A
Rationale:
• Clinical Clue: Selective effect on 70S ribosomes.
• Mechanism: Prokaryotes contain 70S ribosomes and lack
membrane-bound nuclei; eukaryotic cytoplasmic
ribosomes are 80S.
• Why the Correct Answer Is Right: Lack of a membrane-
bound nucleus is a defining prokaryotic feature associated
with 70S ribosomes.
• Why the Other Options Are Wrong:
o B: Microtubules are eukaryotic but not the primary
explanation.
o C: Peptidoglycan is found in cell walls, not plasma
membranes.
o D: Mitochondria distinguish eukaryotes but do not
directly explain ribosomal susceptibility.
,• Exam Trap: Confusing ribosomal differences with
organelle differences alone.
• High-Yield Clinical Correlation: Many antibiotics target
bacterial ribosomes.
• Memory Anchor: Prokaryote = no nucleus + 70S.
Q2. A child develops recurrent respiratory infections due
to impaired ciliary motion in airway epithelial cells. The
underlying defect most likely involves disruption of which
cellular structure?
A. Intermediate filaments
B. Actin microfilaments
C. Microtubules
D. Gap junctions
Correct Answer: C
Rationale:
• Clinical Clue: Defective ciliary movement.
• Mechanism: Cilia rely on microtubules arranged in a 9+2
axonemal pattern with dynein-mediated motion.
• Why the Correct Answer Is Right: Microtubules form the
structural basis of motile cilia.
• Why the Other Options Are Wrong:
o A: Intermediate filaments provide tensile support.
, o B: Actin supports cell shape and contraction but not
ciliary axonemes.
o D: Gap junctions mediate communication.
• Exam Trap: Choosing actin because it mediates movement
in other contexts.
• High-Yield Clinical Correlation: Primary ciliary dyskinesia
causes recurrent infections and infertility.
• Memory Anchor: Cilia ride on microtubule rails.
Q3. A patient with severe alcohol-associated liver injury
demonstrates impaired detoxification of drugs and toxins.
Damage to which organelle best accounts for this
functional decline?
A. Golgi apparatus
B. Rough endoplasmic reticulum
C. Lysosome
D. Smooth endoplasmic reticulum
Correct Answer: D
Rationale:
• Clinical Clue: Impaired detoxification.
• Mechanism: Smooth endoplasmic reticulum contains
enzymes involved in lipid metabolism and xenobiotic
detoxification.
