COMSAE PHASE 1 (FORM 104) LEVEL 1 NEWEST
EXAM QUESTIONS AND CORRECT DETAILED
ANSWERS A NEW UPDATED VERSION LATEST
2026-2027 (VERIFIED ANSWERS) COMLEX
LEVEL 1 FORM 104 EXAM ALREADY GRADED
A+
1. A 45-year-old man presents with chest pain radiating to the left arm,
diaphoresis, and nausea. ECG shows ST elevation in leads II, III, and aVF.
Which artery is most likely occluded?
A. Left anterior descending artery
B. Right coronary artery
C. Circumflex artery
D. Left main coronary artery
Rationale: Inferior wall myocardial infarction (II, III, aVF) is most commonly due
to occlusion of the right coronary artery. The RCA supplies the inferior wall and
frequently the AV node, explaining the bradycardia often seen in these patients.
2. A 23-year-old woman presents with fatigue, pallor, and lab findings showing
microcytic hypochromic anemia. Which is the most likely cause?
A. Vitamin B12 deficiency
B. Iron deficiency
,C. Aplastic anemia
D. Hemolytic anemia
Rationale: Microcytic hypochromic anemia is classically caused by iron deficiency
due to chronic blood loss or poor dietary intake. Vitamin B12 deficiency causes
macrocytic anemia.
3. A patient with chronic alcohol use presents with confusion, ataxia, and
ophthalmoplegia. What is the most appropriate immediate treatment?
A. Oral thiamine
B. IV glucose
C. IV thiamine before glucose
D. Diazepam
Rationale: Wernicke encephalopathy requires immediate IV thiamine before
glucose administration to prevent precipitation or worsening of neurologic injury.
4. Which vitamin deficiency causes night blindness?
A. Vitamin A
B. Vitamin D
C. Vitamin C
D. Vitamin K
Rationale: Vitamin A is required for rhodopsin formation in retinal rods, which is
essential for low-light vision. Deficiency leads to night blindness.
5. A patient has muscle weakness and decreased deep tendon reflexes with low
potassium. What is the most likely cause?
,A. Hyperkalemia
B. Hypokalemia
C. Hypernatremia
D. Hypocalcemia
Rationale: Hypokalemia causes muscle weakness and hyporeflexia due to impaired
membrane excitability and altered resting membrane potential.
6. Which organelle is responsible for ATP production?
A. Nucleus
B. Ribosome
C. Mitochondria
D. Golgi apparatus
Rationale: Mitochondria generate ATP through oxidative phosphorylation,
utilizing the electron transport chain and chemiosmosis.
7. A 55-year-old woman presents with fatigue, weight gain, and cold
intolerance. Labs: TSH 15 µIU/mL (0.4–4.0), free T4 0.5 ng/dL (0.8–1.8).
Which is the most likely diagnosis?
A. Subclinical hypothyroidism
B. Primary hypothyroidism
C. Central hypothyroidism
D. Euthyroid sick syndrome
Rationale: Elevated TSH with low free T4 indicates primary thyroid failure
(Hashimoto's thyroiditis). The pituitary attempts to stimulate the failing gland, but
the gland cannot produce sufficient T4.
8. Which immune cells produce antibodies?
, A. T cells
B. B cells
C. Natural killer cells
D. Macrophages
Rationale: B cells differentiate into plasma cells that produce antibodies. T cells
are involved in cell-mediated immunity.
9. A 65-year-old man has resting tremor, bradykinesia, and postural
instability. Loss of which structure is most responsible?
A. Caudate nucleus
B. Substantia nigra pars compacta
C. Globus pallidus externus
D. Subthalamic nucleus
Rationale: Parkinson disease is characterized by degeneration of dopaminergic
neurons in the substantia nigra pars compacta, leading to reduced dopamine input
to the striatum.
10. A newborn has cyanosis that improves when crying but worsens when
feeding. Which condition is most likely?
A. Tetralogy of Fallot
B. Transposition of great arteries
C. Tricuspid atresia
D. Patent ductus arteriosus
Rationale: Hypercyanotic "tet spells" in Tetralogy of Fallot are relieved by
increased systemic vascular resistance (such as crying) and worsened when SVR
decreases (such as during feeding). Crying increases SVR and improves pulmonary
blood flow.
EXAM QUESTIONS AND CORRECT DETAILED
ANSWERS A NEW UPDATED VERSION LATEST
2026-2027 (VERIFIED ANSWERS) COMLEX
LEVEL 1 FORM 104 EXAM ALREADY GRADED
A+
1. A 45-year-old man presents with chest pain radiating to the left arm,
diaphoresis, and nausea. ECG shows ST elevation in leads II, III, and aVF.
Which artery is most likely occluded?
A. Left anterior descending artery
B. Right coronary artery
C. Circumflex artery
D. Left main coronary artery
Rationale: Inferior wall myocardial infarction (II, III, aVF) is most commonly due
to occlusion of the right coronary artery. The RCA supplies the inferior wall and
frequently the AV node, explaining the bradycardia often seen in these patients.
2. A 23-year-old woman presents with fatigue, pallor, and lab findings showing
microcytic hypochromic anemia. Which is the most likely cause?
A. Vitamin B12 deficiency
B. Iron deficiency
,C. Aplastic anemia
D. Hemolytic anemia
Rationale: Microcytic hypochromic anemia is classically caused by iron deficiency
due to chronic blood loss or poor dietary intake. Vitamin B12 deficiency causes
macrocytic anemia.
3. A patient with chronic alcohol use presents with confusion, ataxia, and
ophthalmoplegia. What is the most appropriate immediate treatment?
A. Oral thiamine
B. IV glucose
C. IV thiamine before glucose
D. Diazepam
Rationale: Wernicke encephalopathy requires immediate IV thiamine before
glucose administration to prevent precipitation or worsening of neurologic injury.
4. Which vitamin deficiency causes night blindness?
A. Vitamin A
B. Vitamin D
C. Vitamin C
D. Vitamin K
Rationale: Vitamin A is required for rhodopsin formation in retinal rods, which is
essential for low-light vision. Deficiency leads to night blindness.
5. A patient has muscle weakness and decreased deep tendon reflexes with low
potassium. What is the most likely cause?
,A. Hyperkalemia
B. Hypokalemia
C. Hypernatremia
D. Hypocalcemia
Rationale: Hypokalemia causes muscle weakness and hyporeflexia due to impaired
membrane excitability and altered resting membrane potential.
6. Which organelle is responsible for ATP production?
A. Nucleus
B. Ribosome
C. Mitochondria
D. Golgi apparatus
Rationale: Mitochondria generate ATP through oxidative phosphorylation,
utilizing the electron transport chain and chemiosmosis.
7. A 55-year-old woman presents with fatigue, weight gain, and cold
intolerance. Labs: TSH 15 µIU/mL (0.4–4.0), free T4 0.5 ng/dL (0.8–1.8).
Which is the most likely diagnosis?
A. Subclinical hypothyroidism
B. Primary hypothyroidism
C. Central hypothyroidism
D. Euthyroid sick syndrome
Rationale: Elevated TSH with low free T4 indicates primary thyroid failure
(Hashimoto's thyroiditis). The pituitary attempts to stimulate the failing gland, but
the gland cannot produce sufficient T4.
8. Which immune cells produce antibodies?
, A. T cells
B. B cells
C. Natural killer cells
D. Macrophages
Rationale: B cells differentiate into plasma cells that produce antibodies. T cells
are involved in cell-mediated immunity.
9. A 65-year-old man has resting tremor, bradykinesia, and postural
instability. Loss of which structure is most responsible?
A. Caudate nucleus
B. Substantia nigra pars compacta
C. Globus pallidus externus
D. Subthalamic nucleus
Rationale: Parkinson disease is characterized by degeneration of dopaminergic
neurons in the substantia nigra pars compacta, leading to reduced dopamine input
to the striatum.
10. A newborn has cyanosis that improves when crying but worsens when
feeding. Which condition is most likely?
A. Tetralogy of Fallot
B. Transposition of great arteries
C. Tricuspid atresia
D. Patent ductus arteriosus
Rationale: Hypercyanotic "tet spells" in Tetralogy of Fallot are relieved by
increased systemic vascular resistance (such as crying) and worsened when SVR
decreases (such as during feeding). Crying increases SVR and improves pulmonary
blood flow.
