COMSAE PHASE 1 ASA 115 (ORIGINAL PRACTICE
EXAM) BY PROF URTOP QUESTIONS AND CORRECT
ANSWERS WITH RATIONALES|LATEST UPDATE 2026
A+ GRADE
1. A 24-year-old man presents with fever, productive cough, and pleuritic
chest pain. Physical examination reveals dullness to percussion and
bronchial breath sounds over the right lower lobe. Which organism is the
most likely cause of community-acquired lobar pneumonia in an otherwise
healthy adult?
A. Mycoplasma pneumoniae
B. Klebsiella pneumoniae
C. Streptococcus pneumoniae
D. Legionella pneumophila
Rationale: Streptococcus pneumoniae is the most common cause of community-
acquired bacterial pneumonia in healthy adults. Lobar consolidation with fever,
productive cough, and pleuritic pain is characteristic.
2. A 3-year-old child has recurrent respiratory infections and absent tonsils on
examination. Laboratory studies reveal markedly decreased
immunoglobulin levels. Which immune cell is primarily deficient?
A. T lymphocyte
B. Neutrophil
C. B lymphocyte
D. Natural killer cell
Rationale: B-cell deficiency (e.g., X-linked agammaglobulinemia) presents after
maternal antibodies disappear with recurrent bacterial infections, absent
lymphoid tissue, and low immunoglobulin levels.
, 3. Which enzyme is inhibited by statin medications?
A. Lipoprotein lipase
B. Cholesterol esterase
C. HMG-CoA reductase
D. Acetyl-CoA carboxylase
Rationale: HMG-CoA reductase catalyzes the rate-limiting step in cholesterol
synthesis. Statins competitively inhibit this enzyme.
4. A patient suddenly develops weakness of the right face, arm, and leg. The
lesion most likely involves which cerebral artery?
A. Posterior cerebral artery
B. Anterior cerebral artery
C. Middle cerebral artery
D. Posterior inferior cerebellar artery
Rationale: Middle cerebral artery infarction commonly causes contralateral face
and arm weakness greater than leg weakness.
5. A 67-year-old smoker presents with painless hematuria. Which diagnosis
should be suspected first?
A. Renal stone
B. Urinary tract infection
C. Bladder carcinoma
D. Glomerulonephritis
Rationale: Painless hematuria in an older smoker is bladder cancer until proven
otherwise.
, 6. During exercise, skeletal muscle blood flow increases primarily because of:
A. Sympathetic vasoconstriction
B. Increased epinephrine release alone
C. Local metabolic vasodilation
D. Increased venous pressure
Rationale: Local metabolites such as adenosine, CO₂, H⁺, and potassium cause
arteriolar dilation, increasing blood flow.
7. Which vitamin deficiency is most likely to produce megaloblastic anemia
with neurologic deficits?
A. Vitamin C
B. Folate
C. Vitamin B12
D. Vitamin K
Rationale: Vitamin B12 deficiency causes megaloblastic anemia and neurologic
dysfunction due to demyelination.
8. A patient has hypercalcemia, kidney stones, and elevated parathyroid
hormone levels. Which diagnosis is most likely?
A. Secondary hyperparathyroidism
B. Familial hypocalciuric hypercalcemia
C. Primary hyperparathyroidism
D. Vitamin D deficiency
Rationale: Elevated PTH with hypercalcemia is classic for primary
hyperparathyroidism, usually due to an adenoma.
EXAM) BY PROF URTOP QUESTIONS AND CORRECT
ANSWERS WITH RATIONALES|LATEST UPDATE 2026
A+ GRADE
1. A 24-year-old man presents with fever, productive cough, and pleuritic
chest pain. Physical examination reveals dullness to percussion and
bronchial breath sounds over the right lower lobe. Which organism is the
most likely cause of community-acquired lobar pneumonia in an otherwise
healthy adult?
A. Mycoplasma pneumoniae
B. Klebsiella pneumoniae
C. Streptococcus pneumoniae
D. Legionella pneumophila
Rationale: Streptococcus pneumoniae is the most common cause of community-
acquired bacterial pneumonia in healthy adults. Lobar consolidation with fever,
productive cough, and pleuritic pain is characteristic.
2. A 3-year-old child has recurrent respiratory infections and absent tonsils on
examination. Laboratory studies reveal markedly decreased
immunoglobulin levels. Which immune cell is primarily deficient?
A. T lymphocyte
B. Neutrophil
C. B lymphocyte
D. Natural killer cell
Rationale: B-cell deficiency (e.g., X-linked agammaglobulinemia) presents after
maternal antibodies disappear with recurrent bacterial infections, absent
lymphoid tissue, and low immunoglobulin levels.
, 3. Which enzyme is inhibited by statin medications?
A. Lipoprotein lipase
B. Cholesterol esterase
C. HMG-CoA reductase
D. Acetyl-CoA carboxylase
Rationale: HMG-CoA reductase catalyzes the rate-limiting step in cholesterol
synthesis. Statins competitively inhibit this enzyme.
4. A patient suddenly develops weakness of the right face, arm, and leg. The
lesion most likely involves which cerebral artery?
A. Posterior cerebral artery
B. Anterior cerebral artery
C. Middle cerebral artery
D. Posterior inferior cerebellar artery
Rationale: Middle cerebral artery infarction commonly causes contralateral face
and arm weakness greater than leg weakness.
5. A 67-year-old smoker presents with painless hematuria. Which diagnosis
should be suspected first?
A. Renal stone
B. Urinary tract infection
C. Bladder carcinoma
D. Glomerulonephritis
Rationale: Painless hematuria in an older smoker is bladder cancer until proven
otherwise.
, 6. During exercise, skeletal muscle blood flow increases primarily because of:
A. Sympathetic vasoconstriction
B. Increased epinephrine release alone
C. Local metabolic vasodilation
D. Increased venous pressure
Rationale: Local metabolites such as adenosine, CO₂, H⁺, and potassium cause
arteriolar dilation, increasing blood flow.
7. Which vitamin deficiency is most likely to produce megaloblastic anemia
with neurologic deficits?
A. Vitamin C
B. Folate
C. Vitamin B12
D. Vitamin K
Rationale: Vitamin B12 deficiency causes megaloblastic anemia and neurologic
dysfunction due to demyelination.
8. A patient has hypercalcemia, kidney stones, and elevated parathyroid
hormone levels. Which diagnosis is most likely?
A. Secondary hyperparathyroidism
B. Familial hypocalciuric hypercalcemia
C. Primary hyperparathyroidism
D. Vitamin D deficiency
Rationale: Elevated PTH with hypercalcemia is classic for primary
hyperparathyroidism, usually due to an adenoma.
