COMSAE Phase 1 Form 104 Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. A 24-year-old man presents with fatigue, pallor, and glossitis. Lab
studies show macrocytic anemia and hypersegmented neutrophils.
Which vitamin deficiency is most likely?
A. Vitamin B1
B. Vitamin B12
C. Vitamin C
D. Vitamin D
Answer: B. Vitamin B12
Vitamin B12 deficiency leads to impaired DNA synthesis causing
megaloblastic anemia with macro-ovalocytes and hypersegmented
neutrophils, often associated with neurologic symptoms.
2. A patient has uncontrolled diabetes mellitus type 1. Which hormone is
primarily deficient?
A. Cortisol
, B. Insulin
C. Glucagon
D. Somatostatin
Answer: B. Insulin
Type 1 diabetes mellitus results from autoimmune destruction of
pancreatic beta cells leading to absolute insulin deficiency.
3. A 60-year-old smoker develops hematuria and a tumor in the bladder.
Which type of cancer is most likely?
A. Adenocarcinoma
B. Squamous cell carcinoma
C. Transitional cell carcinoma
D. Small cell carcinoma
Answer: C. Transitional cell carcinoma
Transitional (urothelial) cell carcinoma is the most common bladder
cancer, strongly associated with smoking and industrial dyes.
4. Which enzyme is deficient in phenylketonuria (PKU)?
A. Homogentisate oxidase
B. Phenylalanine hydroxylase
C. Tyrosinase
D. Glucose-6-phosphatase
Answer: B. Phenylalanine hydroxylase
PKU is caused by deficiency of phenylalanine hydroxylase leading to
, accumulation of phenylalanine and intellectual disability if
untreated.
5. A patient has a prolonged PT that corrects with vitamin K
administration. Which clotting factor is affected first?
A. Factor I
B. Factor VII
C. Factor VIII
D. Factor XIII
Answer: B. Factor VII
Factor VII has the shortest half-life and is first affected in vitamin K
deficiency or warfarin therapy.
6. A 5-year-old child presents with “slapped cheek” rash. What is the
causative agent?
A. Parvovirus B19
B. Epstein-Barr virus
C. Rubella virus
D. Measles virus
Answer: A. Parvovirus B19
Parvovirus B19 causes erythema infectiosum characterized by
slapped cheek rash and can cause aplastic crisis.
7. A patient with COPD is given oxygen therapy. What is the main risk of
high-flow oxygen?
A. Metabolic alkalosis
, B. Respiratory acidosis
C. Hypoglycemia
D. Seizures
Answer: B. Respiratory acidosis
In COPD patients, high oxygen can suppress hypoxic respiratory drive
leading to CO2 retention and respiratory acidosis.
8. Which drug is a competitive inhibitor of ACE?
A. Lisinopril
B. Losartan
C. Propranolol
D. Furosemide
Answer: A. Lisinopril
ACE inhibitors like lisinopril block conversion of angiotensin I to
angiotensin II, reducing blood pressure.
9. A patient has Graves disease. Which antibody is most likely present?
A. Anti-thyroglobulin
B. Anti-TSH receptor
C. Anti-TPO
D. Anti-insulin
Answer: B. Anti-TSH receptor
Graves disease is caused by stimulating autoantibodies against TSH
receptors leading to hyperthyroidism.
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. A 24-year-old man presents with fatigue, pallor, and glossitis. Lab
studies show macrocytic anemia and hypersegmented neutrophils.
Which vitamin deficiency is most likely?
A. Vitamin B1
B. Vitamin B12
C. Vitamin C
D. Vitamin D
Answer: B. Vitamin B12
Vitamin B12 deficiency leads to impaired DNA synthesis causing
megaloblastic anemia with macro-ovalocytes and hypersegmented
neutrophils, often associated with neurologic symptoms.
2. A patient has uncontrolled diabetes mellitus type 1. Which hormone is
primarily deficient?
A. Cortisol
, B. Insulin
C. Glucagon
D. Somatostatin
Answer: B. Insulin
Type 1 diabetes mellitus results from autoimmune destruction of
pancreatic beta cells leading to absolute insulin deficiency.
3. A 60-year-old smoker develops hematuria and a tumor in the bladder.
Which type of cancer is most likely?
A. Adenocarcinoma
B. Squamous cell carcinoma
C. Transitional cell carcinoma
D. Small cell carcinoma
Answer: C. Transitional cell carcinoma
Transitional (urothelial) cell carcinoma is the most common bladder
cancer, strongly associated with smoking and industrial dyes.
4. Which enzyme is deficient in phenylketonuria (PKU)?
A. Homogentisate oxidase
B. Phenylalanine hydroxylase
C. Tyrosinase
D. Glucose-6-phosphatase
Answer: B. Phenylalanine hydroxylase
PKU is caused by deficiency of phenylalanine hydroxylase leading to
, accumulation of phenylalanine and intellectual disability if
untreated.
5. A patient has a prolonged PT that corrects with vitamin K
administration. Which clotting factor is affected first?
A. Factor I
B. Factor VII
C. Factor VIII
D. Factor XIII
Answer: B. Factor VII
Factor VII has the shortest half-life and is first affected in vitamin K
deficiency or warfarin therapy.
6. A 5-year-old child presents with “slapped cheek” rash. What is the
causative agent?
A. Parvovirus B19
B. Epstein-Barr virus
C. Rubella virus
D. Measles virus
Answer: A. Parvovirus B19
Parvovirus B19 causes erythema infectiosum characterized by
slapped cheek rash and can cause aplastic crisis.
7. A patient with COPD is given oxygen therapy. What is the main risk of
high-flow oxygen?
A. Metabolic alkalosis
, B. Respiratory acidosis
C. Hypoglycemia
D. Seizures
Answer: B. Respiratory acidosis
In COPD patients, high oxygen can suppress hypoxic respiratory drive
leading to CO2 retention and respiratory acidosis.
8. Which drug is a competitive inhibitor of ACE?
A. Lisinopril
B. Losartan
C. Propranolol
D. Furosemide
Answer: A. Lisinopril
ACE inhibitors like lisinopril block conversion of angiotensin I to
angiotensin II, reducing blood pressure.
9. A patient has Graves disease. Which antibody is most likely present?
A. Anti-thyroglobulin
B. Anti-TSH receptor
C. Anti-TPO
D. Anti-insulin
Answer: B. Anti-TSH receptor
Graves disease is caused by stimulating autoantibodies against TSH
receptors leading to hyperthyroidism.
