The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A researcher exposes cultured hepatocytes to a toxin
that selectively disrupts rough endoplasmic reticulum
, function. Several hours later, the cells demonstrate
impaired secretion of plasma proteins. Which
pathophysiologic change most directly explains this
finding?
A. Failure of ATP generation within mitochondrial cristae
B. Impaired synthesis of membrane-bound and secretory
proteins
C. Inability to initiate lysosomal autophagy
D. Loss of phospholipid synthesis within peroxisomes
Correct Answer: B
Rationale:
• Clinical Clue: Reduced plasma protein secretion after
rough endoplasmic reticulum injury points to defective
protein synthesis.
• Mechanism: Ribosomes attached to rough endoplasmic
reticulum synthesize proteins destined for secretion,
membrane insertion, or lysosomal use.
• Why the Correct Answer Is Right: Disruption of rough
endoplasmic reticulum prevents translation and
processing of secretory proteins such as albumin and
clotting factors.
• Why the Other Options Are Wrong:
o A: Mitochondria generate ATP but do not directly
synthesize secretory proteins.
, o C: Lysosomal autophagy is unrelated to initial plasma
protein synthesis.
o D: Peroxisomes primarily participate in fatty acid
oxidation and detoxification.
• Exam Trap: Confusing smooth and rough endoplasmic
reticulum functions.
• High-Yield Clinical Correlation: Hepatic injury commonly
reduces serum albumin because hepatocytes rely heavily
on rough endoplasmic reticulum activity.
• Memory Anchor: “Rough ER = Ribosome-rich protein
factory.”
Q2. A mutation causes loss of cadherin-mediated adhesion
between epithelial cells. Which consequence would most
likely develop in affected tissues?
A. Increased intracellular calcium sequestration
B. Impaired anchoring between adjacent cells
C. Enhanced mitochondrial oxidative phosphorylation
D. Failure of DNA transcription initiation
Correct Answer: B
Rationale:
• Clinical Clue: Cadherins are major adhesion molecules
linking neighboring cells.
, • Mechanism: Cadherins form calcium-dependent junctions
that maintain tissue architecture and cellular cohesion.
• Why the Correct Answer Is Right: Loss of cadherin function
weakens intercellular adhesion, increasing tissue
disorganization and invasive potential.
• Why the Other Options Are Wrong:
o A: Calcium sequestration is largely regulated by
endoplasmic reticulum and membrane pumps.
o C: Oxidative phosphorylation occurs independently
within mitochondria.
o D: DNA transcription depends on nuclear regulatory
proteins, not cadherins.
• Exam Trap: Mixing cadherins with integrins, which anchor
cells to extracellular matrix.
• High-Yield Clinical Correlation: Reduced E-cadherin
expression is associated with tumor invasion and
metastasis.
• Memory Anchor: “Cadherins connect cells side-by-side.”
Q3. A patient with severe hypoxemia develops cellular
swelling and reduced membrane potential. Which
underlying process best accounts for these early changes?