1
WGU D115 Advanced Pathophysiology
2025/2026 | 100-Question Practice Exam |
Original Graduate-Level MCQs with
Competency Rationales | OA Test Bank
1. Which intracellular change is the earliest reversible marker of hypoxic
injury?
A. Cytochrome-c release from mitochondria
B. Ribosomal detachment from rough ER
C. ATP depletion → Na⁺/K⁺ pump failure
D. Caspase-3 activation
Answer: C
Rationale: ATP loss (≤10 % of normal) stops Na⁺/K⁺-ATPase → cell swelling; still
fully reversible if O₂ restored.
2. A 45-year-old woman has BRCA1 Δ185AG mutation. Which DNA repair
pathway is defective?
A. Base-excision repair
B. Nucleotide-excision repair
C. Homologous recombination
D. Mismatch repair
Answer: C
Rationale: BRCA1 binds RAD51 to promote homologous-recombination double-
strand break repair; loss leads to chromosomal instability.
3. In stable angina, which adenosine receptor mediates coronary vasodilation
during ischemia?
A. A1
B. A2A
C. A2B
D. A3
, 2
Answer: B
Rationale: A2A on vascular smooth muscle ↑cAMP → vasodilation; explains
thallium “reverse redistribution.”
4. A diabetic patient has HbA1c 9.2 %. Which pathophysiologic process most
contributes to glycation?
A. Non-enzymatic Amadori rearrangement
B. Enzymatic fructosamine phosphorylation
C. Sorbitol accumulation via aldose reductase
D. PKC-β activation by diacylglycerol
Answer: A
Rationale: Glucose condenses with N-terminal valine of Hb forming Schiff base →
Amadori product → HbA1c.
5. Which cytokine is the primary driver of muscle proteolysis in cancer
cachexia?
A. IL-2
B. IL-6
C. IL-8
D. IL-10
Answer: B
Rationale: IL-6 via JAK/STAT3 induces atrogin-1/MAFbx ubiquitin ligase in
skeletal muscle.
6. Mutation in which receptor causes familial hypercholesterolemia?
A. LDL receptor
B. HDL receptor (SR-B1)
C. VLDL receptor
D. PCSK9
Answer: A
Rationale: Loss-of-function LDL-R ↓hepatic LDL uptake → plasma LDL-C ↑ and
premature atherosclerosis.
7. A 6-year-old boy has recurrent Burkholderia infections and absent CD15s on
neutrophils. Diagnosis?
A. Chronic granulomatous disease
B. Leukocyte adhesion deficiency-1
, 3
C. Chediak-Higashi syndrome
D. Hyper-IgE syndrome
Answer: B
Rationale: LAD-1 due to ITGB2 mutation → β2-integrin (CD18) deficiency;
CD15s (sialyl-Lewis X) is normal but CD11/CD18 absent.
8. Which ECG change is pathognomonic of hypokalemia?
A. Peaked T waves
B. U waves
C. Short QT interval
D. Delta wave
Answer: B
Rationale: Prominent U wave (interposed between T and P) reflects prolonged
phase-3 repolarisation.
9. Macrocytic anemia with hypersegmented neutrophils is caused by defective:
A. δ-ALA synthase
B. Methylmalonyl-CoA mutase
C. Methionine synthase
D. Ferrochelatase
Answer: C
Rationale: B12 deficiency blocks methionine synthase → folate trapped as 5 -
methyl-THF → impaired dTMP synthesis.
10.In ARDS, which pathophysiologic event causes refractory hypoxemia?
A. Ventilation-perfusion ratio = 1
B. Intrapulmonary shunt >30 %
C. Decreased PaCO₂
D. Increased P(A-a)O₂ with hyperventilation
Answer: B
Rationale: Collapsed alveoli perfused but not ventilated → true shunt;
supplemental O₂ fails to correct.
11.Which autoantibody is specific for Graves disease?
A. Anti-TPO
B. TSH-receptor stimulating (TSI)
WGU D115 Advanced Pathophysiology
2025/2026 | 100-Question Practice Exam |
Original Graduate-Level MCQs with
Competency Rationales | OA Test Bank
1. Which intracellular change is the earliest reversible marker of hypoxic
injury?
A. Cytochrome-c release from mitochondria
B. Ribosomal detachment from rough ER
C. ATP depletion → Na⁺/K⁺ pump failure
D. Caspase-3 activation
Answer: C
Rationale: ATP loss (≤10 % of normal) stops Na⁺/K⁺-ATPase → cell swelling; still
fully reversible if O₂ restored.
2. A 45-year-old woman has BRCA1 Δ185AG mutation. Which DNA repair
pathway is defective?
A. Base-excision repair
B. Nucleotide-excision repair
C. Homologous recombination
D. Mismatch repair
Answer: C
Rationale: BRCA1 binds RAD51 to promote homologous-recombination double-
strand break repair; loss leads to chromosomal instability.
3. In stable angina, which adenosine receptor mediates coronary vasodilation
during ischemia?
A. A1
B. A2A
C. A2B
D. A3
, 2
Answer: B
Rationale: A2A on vascular smooth muscle ↑cAMP → vasodilation; explains
thallium “reverse redistribution.”
4. A diabetic patient has HbA1c 9.2 %. Which pathophysiologic process most
contributes to glycation?
A. Non-enzymatic Amadori rearrangement
B. Enzymatic fructosamine phosphorylation
C. Sorbitol accumulation via aldose reductase
D. PKC-β activation by diacylglycerol
Answer: A
Rationale: Glucose condenses with N-terminal valine of Hb forming Schiff base →
Amadori product → HbA1c.
5. Which cytokine is the primary driver of muscle proteolysis in cancer
cachexia?
A. IL-2
B. IL-6
C. IL-8
D. IL-10
Answer: B
Rationale: IL-6 via JAK/STAT3 induces atrogin-1/MAFbx ubiquitin ligase in
skeletal muscle.
6. Mutation in which receptor causes familial hypercholesterolemia?
A. LDL receptor
B. HDL receptor (SR-B1)
C. VLDL receptor
D. PCSK9
Answer: A
Rationale: Loss-of-function LDL-R ↓hepatic LDL uptake → plasma LDL-C ↑ and
premature atherosclerosis.
7. A 6-year-old boy has recurrent Burkholderia infections and absent CD15s on
neutrophils. Diagnosis?
A. Chronic granulomatous disease
B. Leukocyte adhesion deficiency-1
, 3
C. Chediak-Higashi syndrome
D. Hyper-IgE syndrome
Answer: B
Rationale: LAD-1 due to ITGB2 mutation → β2-integrin (CD18) deficiency;
CD15s (sialyl-Lewis X) is normal but CD11/CD18 absent.
8. Which ECG change is pathognomonic of hypokalemia?
A. Peaked T waves
B. U waves
C. Short QT interval
D. Delta wave
Answer: B
Rationale: Prominent U wave (interposed between T and P) reflects prolonged
phase-3 repolarisation.
9. Macrocytic anemia with hypersegmented neutrophils is caused by defective:
A. δ-ALA synthase
B. Methylmalonyl-CoA mutase
C. Methionine synthase
D. Ferrochelatase
Answer: C
Rationale: B12 deficiency blocks methionine synthase → folate trapped as 5 -
methyl-THF → impaired dTMP synthesis.
10.In ARDS, which pathophysiologic event causes refractory hypoxemia?
A. Ventilation-perfusion ratio = 1
B. Intrapulmonary shunt >30 %
C. Decreased PaCO₂
D. Increased P(A-a)O₂ with hyperventilation
Answer: B
Rationale: Collapsed alveoli perfused but not ventilated → true shunt;
supplemental O₂ fails to correct.
11.Which autoantibody is specific for Graves disease?
A. Anti-TPO
B. TSH-receptor stimulating (TSI)
