, Question 1
A cell exhibits mitochondrial permeability transition pore opening, ATP
depletion to <10% of normal, and lysosomal enzyme leakage. Which outcome
is most consistent with these findings?
A. Reversible cell swelling
B. Apoptosis via intrinsic pathway
C. Coagulative necrosis
D. Autophagic vacuole formation
Correct Answer: C - Coagulative necrosis
RATIONALE
Severe ATP depletion with mitochondrial permeability transition and
lysosomal rupture drives necrotic cell death, typically coagulative in
ischemic tissues. Apoptosis is ATP-dependent and does not involve
lysosomal leakage.
Question 2
A child inherits a pathogenic variant in a gene subject to genomic imprinting.
The same variant inherited from the other parent causes no disease. Which
concept best explains this?
A. Anticipation
B. Parent-of-origin effect
C. Mosaicism
D. Uniparental disomy
Correct Answer: B - Parent-of-origin effect
RATIONALE
Parent-of-origin effects occur when imprinted genes are expressed
differently depending on the parent of origin, so only the allele from
the expressing parent causes disease. Anticipation involves increasing
severity across generations, not parent-specific expression.
Page 2
, Question 3
Which laboratory finding best distinguishes iron deficiency anemia from
anemia of chronic disease?
A. Low serum ferritin in iron deficiency; normal or high ferritin in
anemia of chronic disease
B. High total iron-binding capacity (TIBC) in anemia of chronic disease;
low TIBC in iron deficiency
C. High transferrin saturation in iron deficiency; low in anemia of chronic
disease
D. Low soluble transferrin receptor in iron deficiency; high in anemia of
chronic disease
Correct Answer: A - Low serum ferritin in iron deficiency;
normal or high ferritin in anemia of chronic disease
RATIONALE
Ferritin reflects iron stores; it is low in iron deficiency and
normal/high in anemia of chronic disease due to inflammation. TIBC
is high in iron deficiency and low/normal in anemia of chronic
disease.
Question 4
A patient with heart failure has an ejection fraction of 30% and elevated
pulmonary capillary wedge pressure. Which pathophysiologic mechanism
primarily accounts for these findings?
A. Impaired diastolic filling
B. Reduced myocardial contractility
C. Increased systemic vascular resistance
D. Pericardial constriction
Correct Answer: B - Reduced myocardial contractility
Page 3
, RATIONALE
A reduced ejection fraction with elevated filling pressures indicates
systolic dysfunction, primarily due to decreased contractility. Diastolic
dysfunction would present with preserved ejection fraction.
Question 5
Which arterial blood gas pattern is most consistent with acute respiratory
distress syndrome (ARDS)?
A. pH 7.48, PaCO2 30, HCO3 22, PaO2 90 on room air
B. pH 7.30, PaCO2 50, HCO3 24, PaO2 55 on room air
C. pH 7.25, PaCO2 30, HCO3 15, PaO2 80 on room air
D. pH 7.50, PaCO2 40, HCO3 30, PaO2 60 on room air
Correct Answer: B - pH 7.30, PaCO2 50, HCO3 24, PaO2 55 on
room air
RATIONALE
ARDS causes severe hypoxemia (PaO2 <60) with respiratory acidosis
due to impaired gas exchange and increased dead space. The other
options do not reflect the typical ARDS pattern.
Question 6
A patient with chronic kidney disease has a glomerular filtration rate of 25
mL/min. Which acid-base disturbance is most likely?
A. Metabolic alkalosis
B. Respiratory alkalosis
C. Metabolic acidosis
D. Respiratory acidosis
Correct Answer: C - Metabolic acidosis
Page 4
A cell exhibits mitochondrial permeability transition pore opening, ATP
depletion to <10% of normal, and lysosomal enzyme leakage. Which outcome
is most consistent with these findings?
A. Reversible cell swelling
B. Apoptosis via intrinsic pathway
C. Coagulative necrosis
D. Autophagic vacuole formation
Correct Answer: C - Coagulative necrosis
RATIONALE
Severe ATP depletion with mitochondrial permeability transition and
lysosomal rupture drives necrotic cell death, typically coagulative in
ischemic tissues. Apoptosis is ATP-dependent and does not involve
lysosomal leakage.
Question 2
A child inherits a pathogenic variant in a gene subject to genomic imprinting.
The same variant inherited from the other parent causes no disease. Which
concept best explains this?
A. Anticipation
B. Parent-of-origin effect
C. Mosaicism
D. Uniparental disomy
Correct Answer: B - Parent-of-origin effect
RATIONALE
Parent-of-origin effects occur when imprinted genes are expressed
differently depending on the parent of origin, so only the allele from
the expressing parent causes disease. Anticipation involves increasing
severity across generations, not parent-specific expression.
Page 2
, Question 3
Which laboratory finding best distinguishes iron deficiency anemia from
anemia of chronic disease?
A. Low serum ferritin in iron deficiency; normal or high ferritin in
anemia of chronic disease
B. High total iron-binding capacity (TIBC) in anemia of chronic disease;
low TIBC in iron deficiency
C. High transferrin saturation in iron deficiency; low in anemia of chronic
disease
D. Low soluble transferrin receptor in iron deficiency; high in anemia of
chronic disease
Correct Answer: A - Low serum ferritin in iron deficiency;
normal or high ferritin in anemia of chronic disease
RATIONALE
Ferritin reflects iron stores; it is low in iron deficiency and
normal/high in anemia of chronic disease due to inflammation. TIBC
is high in iron deficiency and low/normal in anemia of chronic
disease.
Question 4
A patient with heart failure has an ejection fraction of 30% and elevated
pulmonary capillary wedge pressure. Which pathophysiologic mechanism
primarily accounts for these findings?
A. Impaired diastolic filling
B. Reduced myocardial contractility
C. Increased systemic vascular resistance
D. Pericardial constriction
Correct Answer: B - Reduced myocardial contractility
Page 3
, RATIONALE
A reduced ejection fraction with elevated filling pressures indicates
systolic dysfunction, primarily due to decreased contractility. Diastolic
dysfunction would present with preserved ejection fraction.
Question 5
Which arterial blood gas pattern is most consistent with acute respiratory
distress syndrome (ARDS)?
A. pH 7.48, PaCO2 30, HCO3 22, PaO2 90 on room air
B. pH 7.30, PaCO2 50, HCO3 24, PaO2 55 on room air
C. pH 7.25, PaCO2 30, HCO3 15, PaO2 80 on room air
D. pH 7.50, PaCO2 40, HCO3 30, PaO2 60 on room air
Correct Answer: B - pH 7.30, PaCO2 50, HCO3 24, PaO2 55 on
room air
RATIONALE
ARDS causes severe hypoxemia (PaO2 <60) with respiratory acidosis
due to impaired gas exchange and increased dead space. The other
options do not reflect the typical ARDS pattern.
Question 6
A patient with chronic kidney disease has a glomerular filtration rate of 25
mL/min. Which acid-base disturbance is most likely?
A. Metabolic alkalosis
B. Respiratory alkalosis
C. Metabolic acidosis
D. Respiratory acidosis
Correct Answer: C - Metabolic acidosis
Page 4
