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COMSAE Phase 1 Form 113 Practice Exam Questions and Correct
Verified Answers Plus Rationales Already Graded A+ 2025-2026 |
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The motor cortex responsible for voluntary movement is located in which gyrus?
CORRECT ANSWER ✓ ✓ Precentral gyrus
A. Superior temporal gyrus
B. Precentral gyrus
C. Postcentral gyrus
D. Precentral gyrus
Rationale: The primary motor cortex is located in the precentral gyrus of the frontal lobe
and controls voluntary movement.
Which amino acid is essential and a precursor for nitric oxide synthesis?
CORRECT ANSWER ✓ ✓ Arginine
A. Lysine
B. Arginine
C. Glycine
D. Glutamine
Rationale: Arginine is the substrate for nitric oxide synthase, producing nitric oxide.
Which heart valve prevents backflow from the left ventricle into the left atrium?
CORRECT ANSWER ✓ ✓ Mitral (bicuspid) valve
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A. Pulmonary valve
B. Tricuspid valve
C. Mitral (bicuspid) valve
D. Aortic valve
Rationale: The mitral valve is between the left atrium and left ventricle and prevents
regurgitation during systole.
A Gram-positive, catalase-positive cocci in clusters is most likely:
CORRECT ANSWER ✓ ✓ Staphylococcus aureus
A. Streptococcus pyogenes
B. Staphylococcus aureus
C. Enterococcus faecalis
D. Neisseria gonorrhoeae
Rationale: Staphylococci are Gram-positive cocci in clusters and are catalase-positive.
Which structure of the nephron is primarily responsible for filtration?
CORRECT ANSWER ✓ ✓ Glomerulus (Bowman capsule)
A. Proximal tubule
B. Loop of Henle
C. Distal tubule
D. Glomerulus (Bowman capsule)
Rationale: Filtration of plasma into Bowman’s space occurs at the glomerulus.
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In glycolysis, the rate-limiting enzyme that converts fructose-6-phosphate to fructose-
1,6-bisphosphate is:
CORRECT ANSWER ✓ ✓ Phosphofructokinase-1 (PFK-1)
A. Hexokinase
B. Pyruvate kinase
C. Phosphofructokinase-1 (PFK-1)
D. Aldolase
Rationale: PFK-1 is the major regulatory, rate-limiting enzyme of glycolysis.
The alveolar gas equation estimates alveolar O₂ tension. Which variable is directly
subtracted from inspired O₂ partial pressure in the simplified alveolar gas equation?
CORRECT ANSWER ✓ ✓ PaCO₂/R
A. PaCO₂/R (where R is respiratory quotient)
B. PaCO₂/R
C. Water vapor pressure
D. Hemoglobin concentration
Rationale: The simplified equation subtracts PaCO₂ divided by R from inspired oxygen
pressure.
A patient with pernicious anemia lacks intrinsic factor. This leads to decreased
absorption of which vitamin?
CORRECT ANSWER ✓ ✓ Vitamin B12 (cobalamin)
A. Vitamin C
B. Vitamin B12 (cobalamin)
COMSAE Phase 1 Form 113 Practice Exam Questions and Correct
Verified Answers Plus Rationales Already Graded A+ 2025-2026 |
Instant Download Pdf
The motor cortex responsible for voluntary movement is located in which gyrus?
CORRECT ANSWER ✓ ✓ Precentral gyrus
A. Superior temporal gyrus
B. Precentral gyrus
C. Postcentral gyrus
D. Precentral gyrus
Rationale: The primary motor cortex is located in the precentral gyrus of the frontal lobe
and controls voluntary movement.
Which amino acid is essential and a precursor for nitric oxide synthesis?
CORRECT ANSWER ✓ ✓ Arginine
A. Lysine
B. Arginine
C. Glycine
D. Glutamine
Rationale: Arginine is the substrate for nitric oxide synthase, producing nitric oxide.
Which heart valve prevents backflow from the left ventricle into the left atrium?
CORRECT ANSWER ✓ ✓ Mitral (bicuspid) valve
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A. Pulmonary valve
B. Tricuspid valve
C. Mitral (bicuspid) valve
D. Aortic valve
Rationale: The mitral valve is between the left atrium and left ventricle and prevents
regurgitation during systole.
A Gram-positive, catalase-positive cocci in clusters is most likely:
CORRECT ANSWER ✓ ✓ Staphylococcus aureus
A. Streptococcus pyogenes
B. Staphylococcus aureus
C. Enterococcus faecalis
D. Neisseria gonorrhoeae
Rationale: Staphylococci are Gram-positive cocci in clusters and are catalase-positive.
Which structure of the nephron is primarily responsible for filtration?
CORRECT ANSWER ✓ ✓ Glomerulus (Bowman capsule)
A. Proximal tubule
B. Loop of Henle
C. Distal tubule
D. Glomerulus (Bowman capsule)
Rationale: Filtration of plasma into Bowman’s space occurs at the glomerulus.
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In glycolysis, the rate-limiting enzyme that converts fructose-6-phosphate to fructose-
1,6-bisphosphate is:
CORRECT ANSWER ✓ ✓ Phosphofructokinase-1 (PFK-1)
A. Hexokinase
B. Pyruvate kinase
C. Phosphofructokinase-1 (PFK-1)
D. Aldolase
Rationale: PFK-1 is the major regulatory, rate-limiting enzyme of glycolysis.
The alveolar gas equation estimates alveolar O₂ tension. Which variable is directly
subtracted from inspired O₂ partial pressure in the simplified alveolar gas equation?
CORRECT ANSWER ✓ ✓ PaCO₂/R
A. PaCO₂/R (where R is respiratory quotient)
B. PaCO₂/R
C. Water vapor pressure
D. Hemoglobin concentration
Rationale: The simplified equation subtracts PaCO₂ divided by R from inspired oxygen
pressure.
A patient with pernicious anemia lacks intrinsic factor. This leads to decreased
absorption of which vitamin?
CORRECT ANSWER ✓ ✓ Vitamin B12 (cobalamin)
A. Vitamin C
B. Vitamin B12 (cobalamin)
