COMLEX-USA LEVEL 1 COMPREHENSIVE PRACTICE
EXAM (COMSAE PHASE 1 ASA 107I) QUESTIONS
WITH CORRECT ANSWERS AND RATIONALES A+
GRADE
1. A 24-year-old woman develops fatigue, pallor, and paresthesia’s several
months after surgical resection of the terminal ileum for Crohn disease.
Laboratory studies reveal macrocytic anemia. Which vitamin deficiency is
the most likely cause?
A. Folate
B. Vitamin B1
C. Vitamin B12
D. Vitamin C
E. Vitamin K
Rationale: Vitamin B12 is absorbed in the terminal ileum. Deficiency causes
megaloblastic anemia and neurologic symptoms such as paresthesias.
2. A researcher administers a drug that competitively inhibits angiotensin-
converting enzyme. Which change is most likely to occur?
A. Increased angiotensin II production
B. Increased aldosterone secretion
C. Decreased systemic vascular resistance
D. Increased bradykinin degradation
E. Increased sodium retention
Rationale: ACE inhibitors decrease angiotensin II formation, reducing
vasoconstriction and systemic vascular resistance while increasing bradykinin
levels.
, 3. A 7-year-old boy has recurrent respiratory infections and situs inversus.
Electron microscopy demonstrates defective dynein arms. Which structure
is primarily affected?
A. Intermediate filaments
B. Microfilaments
C. Microtubules
D. Tight junctions
E. Desmosomes
Rationale: Primary ciliary dyskinesia results from defective dynein arms within
microtubules, impairing ciliary movement.
4. A patient experiences severe chest pain for 3 hours. Histologic examination
would most likely demonstrate which early change?
A. Fibrosis
B. Granulation tissue
C. Coagulative necrosis with neutrophilic infiltration
D. Macrophage infiltration
E. Wavy myocardial fibers
Rationale: Wavy fibers are among the earliest microscopic findings after
myocardial infarction, appearing within several hours.
5. A patient with asthma receives inhaled albuterol. Activation of which
receptor mediates bronchodilation?
A. α1
B. β1
C. β2
D. M2
E. M3
, Rationale: β2-adrenergic receptor activation relaxes bronchial smooth muscle
through increased cAMP.
6. Which bacterium is the most common cause of community-acquired
pneumonia in otherwise healthy adults?
A. Staphylococcus aureus
B. Klebsiella pneumoniae
C. Haemophilus influenzae
D. Streptococcus pneumoniae
E. Legionella pneumophila
Rationale: Streptococcus pneumoniae remains the leading cause of community-
acquired pneumonia.
7. A patient develops nephrotic syndrome with diffuse effacement of
podocyte foot processes seen on electron microscopy. Which diagnosis is
most likely?
A. Membranous nephropathy
B. Focal segmental glomerulosclerosis
C. Minimal change disease
D. Rapidly progressive glomerulonephritis
E. IgA nephropathy
Rationale: Minimal change disease is characterized by podocyte foot process
effacement and typically responds well to corticosteroids.
8. During exercise, skeletal muscle blood flow increases primarily because of:
A. Increased sympathetic vasoconstriction
B. Decreased nitric oxide production
C. Local metabolic vasodilation
EXAM (COMSAE PHASE 1 ASA 107I) QUESTIONS
WITH CORRECT ANSWERS AND RATIONALES A+
GRADE
1. A 24-year-old woman develops fatigue, pallor, and paresthesia’s several
months after surgical resection of the terminal ileum for Crohn disease.
Laboratory studies reveal macrocytic anemia. Which vitamin deficiency is
the most likely cause?
A. Folate
B. Vitamin B1
C. Vitamin B12
D. Vitamin C
E. Vitamin K
Rationale: Vitamin B12 is absorbed in the terminal ileum. Deficiency causes
megaloblastic anemia and neurologic symptoms such as paresthesias.
2. A researcher administers a drug that competitively inhibits angiotensin-
converting enzyme. Which change is most likely to occur?
A. Increased angiotensin II production
B. Increased aldosterone secretion
C. Decreased systemic vascular resistance
D. Increased bradykinin degradation
E. Increased sodium retention
Rationale: ACE inhibitors decrease angiotensin II formation, reducing
vasoconstriction and systemic vascular resistance while increasing bradykinin
levels.
, 3. A 7-year-old boy has recurrent respiratory infections and situs inversus.
Electron microscopy demonstrates defective dynein arms. Which structure
is primarily affected?
A. Intermediate filaments
B. Microfilaments
C. Microtubules
D. Tight junctions
E. Desmosomes
Rationale: Primary ciliary dyskinesia results from defective dynein arms within
microtubules, impairing ciliary movement.
4. A patient experiences severe chest pain for 3 hours. Histologic examination
would most likely demonstrate which early change?
A. Fibrosis
B. Granulation tissue
C. Coagulative necrosis with neutrophilic infiltration
D. Macrophage infiltration
E. Wavy myocardial fibers
Rationale: Wavy fibers are among the earliest microscopic findings after
myocardial infarction, appearing within several hours.
5. A patient with asthma receives inhaled albuterol. Activation of which
receptor mediates bronchodilation?
A. α1
B. β1
C. β2
D. M2
E. M3
, Rationale: β2-adrenergic receptor activation relaxes bronchial smooth muscle
through increased cAMP.
6. Which bacterium is the most common cause of community-acquired
pneumonia in otherwise healthy adults?
A. Staphylococcus aureus
B. Klebsiella pneumoniae
C. Haemophilus influenzae
D. Streptococcus pneumoniae
E. Legionella pneumophila
Rationale: Streptococcus pneumoniae remains the leading cause of community-
acquired pneumonia.
7. A patient develops nephrotic syndrome with diffuse effacement of
podocyte foot processes seen on electron microscopy. Which diagnosis is
most likely?
A. Membranous nephropathy
B. Focal segmental glomerulosclerosis
C. Minimal change disease
D. Rapidly progressive glomerulonephritis
E. IgA nephropathy
Rationale: Minimal change disease is characterized by podocyte foot process
effacement and typically responds well to corticosteroids.
8. During exercise, skeletal muscle blood flow increases primarily because of:
A. Increased sympathetic vasoconstriction
B. Decreased nitric oxide production
C. Local metabolic vasodilation
