COMSAE Phase 1 Form A Questions With
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. A 24-year-old male presents with fever, sore throat, and posterior
cervical lymphadenopathy. A heterophile antibody test is positive.
Which virus is most likely responsible?
A. Cytomegalovirus
B. Epstein-Barr virus
C. Adenovirus
D. Toxoplasma gondii
Answer: B
Rationale: The presentation is classic for infectious
mononucleosis caused by Epstein-Barr virus. Positive heterophile
antibody (Monospot) supports EBV infection.
2. Which structure is primarily responsible for producing
cerebrospinal fluid?
A. Choroid plexus
, B. Arachnoid villi
C. Dura mater
D. Ependymal cells of spinal cord central canal
Answer: A
Rationale: The choroid plexus within the ventricles produces
most cerebrospinal fluid.
3. A patient has right-sided hemiparesis and aphasia. Which artery is
most likely occluded?
A. Posterior cerebral artery
B. Anterior cerebral artery
C. Left middle cerebral artery
D. Basilar artery
Answer: C
Rationale: Left middle cerebral artery strokes affect language
(dominant hemisphere) and cause contralateral motor deficits.
4. Which immunoglobulin is the first produced in a primary immune
response?
A. IgG
B. IgA
, C. IgM
D. IgE
Answer: C
Rationale: IgM is the first antibody produced in initial immune
responses.
5. Which vitamin deficiency is associated with Wernicke
encephalopathy?
A. Vitamin B1 (thiamine)
B. Vitamin B6
C. Vitamin B12
D. Vitamin C
Answer: A
Rationale: Thiamine deficiency leads to Wernicke
encephalopathy, especially in alcohol use disorder.
6. Which part of the nephron is primarily responsible for glucose
reabsorption?
A. Loop of Henle
B. Proximal convoluted tubule
C. Distal convoluted tubule
, D. Collecting duct
Answer: B
Rationale: The proximal convoluted tubule reabsorbs nearly all
filtered glucose via SGLT transporters.
7. A mutation causes defective collagen type I synthesis. Which
disease is most likely?
A. Ehlers-Danlos syndrome
B. Osteogenesis imperfecta
C. Marfan syndrome
D. Menkes disease
Answer: B
Rationale: Osteogenesis imperfecta is caused by defective type I
collagen leading to brittle bones.
8. Which hormone increases calcium reabsorption in the distal
tubule of the kidney?
A. Calcitonin
B. Parathyroid hormone
C. Aldosterone
D. Vitamin D
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. A 24-year-old male presents with fever, sore throat, and posterior
cervical lymphadenopathy. A heterophile antibody test is positive.
Which virus is most likely responsible?
A. Cytomegalovirus
B. Epstein-Barr virus
C. Adenovirus
D. Toxoplasma gondii
Answer: B
Rationale: The presentation is classic for infectious
mononucleosis caused by Epstein-Barr virus. Positive heterophile
antibody (Monospot) supports EBV infection.
2. Which structure is primarily responsible for producing
cerebrospinal fluid?
A. Choroid plexus
, B. Arachnoid villi
C. Dura mater
D. Ependymal cells of spinal cord central canal
Answer: A
Rationale: The choroid plexus within the ventricles produces
most cerebrospinal fluid.
3. A patient has right-sided hemiparesis and aphasia. Which artery is
most likely occluded?
A. Posterior cerebral artery
B. Anterior cerebral artery
C. Left middle cerebral artery
D. Basilar artery
Answer: C
Rationale: Left middle cerebral artery strokes affect language
(dominant hemisphere) and cause contralateral motor deficits.
4. Which immunoglobulin is the first produced in a primary immune
response?
A. IgG
B. IgA
, C. IgM
D. IgE
Answer: C
Rationale: IgM is the first antibody produced in initial immune
responses.
5. Which vitamin deficiency is associated with Wernicke
encephalopathy?
A. Vitamin B1 (thiamine)
B. Vitamin B6
C. Vitamin B12
D. Vitamin C
Answer: A
Rationale: Thiamine deficiency leads to Wernicke
encephalopathy, especially in alcohol use disorder.
6. Which part of the nephron is primarily responsible for glucose
reabsorption?
A. Loop of Henle
B. Proximal convoluted tubule
C. Distal convoluted tubule
, D. Collecting duct
Answer: B
Rationale: The proximal convoluted tubule reabsorbs nearly all
filtered glucose via SGLT transporters.
7. A mutation causes defective collagen type I synthesis. Which
disease is most likely?
A. Ehlers-Danlos syndrome
B. Osteogenesis imperfecta
C. Marfan syndrome
D. Menkes disease
Answer: B
Rationale: Osteogenesis imperfecta is caused by defective type I
collagen leading to brittle bones.
8. Which hormone increases calcium reabsorption in the distal
tubule of the kidney?
A. Calcitonin
B. Parathyroid hormone
C. Aldosterone
D. Vitamin D
