COMSAE PHASE 1 FORM 117
QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A |
INSTANT DOWNLOAD PDF
CORE DOMAINS
Osteopathic Principles and Manipulative Medicine
Anatomy and Embryology
Physiology and Pathophysiology
Biochemistry and Molecular Biology
Pharmacology and Pharmacotherapeutics
Microbiology and Immunology
Pathology and Laboratory Medicine
Behavioral Science and Ethics
Clinical Integration and Systems-Based Practice
INTRODUCTION
This comprehensive self-assessment examination is designed for
osteopathic medical students preparing for COMLEX-USA Level 1. It
evaluates foundational biomedical sciences, osteopathic principles,
and clinical reasoning through scenario-based questions. The
structure integrates anatomy, physiology, pathology, pharmacology,
microbiology, and behavioral science with osteopathic manipulative
medicine. Emphasis is placed on applying basic science knowledge to
clinical vignettes, interpreting laboratory findings, and
,demonstrating whole-person care. Detailed rationales reinforce high-
yield concepts and decision-making. Success requires critical
thinking, integration of systems, and readiness for licensure-level
assessment. This exam serves as a rigorous benchmark for
professional competency.
SECTION ONE: QUESTIONS 1-160
1. A newborn with classic galactosemia is most likely deficient in
which enzyme?
A. Galactokinase
B. Galactose-1-phosphate uridyltransferase
C. Uridine diphosphate galactose-4-epimerase
D. Aldose reductase
B. Galactose-1-phosphate uridyltransferase
RATIONALE: Classic galactosemia is caused by deficiency of
galactose-1-phosphate uridyltransferase (GALT). Infants present
with jaundice, hepatomegaly, cataracts, and failure to thrive after
milk ingestion.
2. Which primary malignant brain tumor is most common in
adults?
A. Meningioma
B. Glioblastoma
C. Medulloblastoma
D. Ependymoma
B. Glioblastoma
, RATIONALE: Glioblastoma is the most common primary
malignant brain tumor in adults. It is a high-grade astrocytoma with
poor prognosis and characteristic necrosis and microvascular
proliferation.
3. Which osteopathic concept describes the inherent motion of
the central nervous system, cerebrospinal fluid, cranial bones,
and sacrum?
A. Somatic dysfunction
B. Primary respiratory mechanism
C. Viscerosomatic reflex
D. Facilitated segment
B. Primary respiratory mechanism
RATIONALE: The primary respiratory mechanism is a core
osteopathic concept involving the inherent motility of the brain and
spinal cord, cerebrospinal fluid, cranial bones, and sacrum.
4. Which antibiotic inhibits the 30S ribosomal subunit?
A. Erythromycin
B. Clindamycin
C. Tetracycline
D. Penicillin
C. Tetracycline
RATIONALE: Tetracyclines bind the 30S ribosomal subunit and
block aminoacyl-tRNA attachment, inhibiting protein synthesis.
5. The midgut is primarily supplied by which artery?
, A. Celiac trunk
B. Superior mesenteric artery
C. Inferior mesenteric artery
D. Internal iliac artery
B. Superior mesenteric artery
RATIONALE: The superior mesenteric artery supplies midgut
derivatives, from the distal duodenum to the proximal two-thirds of
the transverse colon.
6. Which area of the brain is responsible for language
comprehension?
A. Broca area
B. Wernicke area
C. Precentral gyrus
D. Postcentral gyrus
B. Wernicke area
RATIONALE: Wernicke area, located in the superior temporal
gyrus of the dominant hemisphere, is responsible for language
comprehension. Damage causes receptive aphasia.
7. Hyperacute rejection of a transplanted organ is mediated by:
A. Preformed recipient antibodies
B. T-cell-mediated cytotoxicity
C. Immune complex deposition
D. Delayed hypersensitivity
A. Preformed recipient antibodies
QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A |
INSTANT DOWNLOAD PDF
CORE DOMAINS
Osteopathic Principles and Manipulative Medicine
Anatomy and Embryology
Physiology and Pathophysiology
Biochemistry and Molecular Biology
Pharmacology and Pharmacotherapeutics
Microbiology and Immunology
Pathology and Laboratory Medicine
Behavioral Science and Ethics
Clinical Integration and Systems-Based Practice
INTRODUCTION
This comprehensive self-assessment examination is designed for
osteopathic medical students preparing for COMLEX-USA Level 1. It
evaluates foundational biomedical sciences, osteopathic principles,
and clinical reasoning through scenario-based questions. The
structure integrates anatomy, physiology, pathology, pharmacology,
microbiology, and behavioral science with osteopathic manipulative
medicine. Emphasis is placed on applying basic science knowledge to
clinical vignettes, interpreting laboratory findings, and
,demonstrating whole-person care. Detailed rationales reinforce high-
yield concepts and decision-making. Success requires critical
thinking, integration of systems, and readiness for licensure-level
assessment. This exam serves as a rigorous benchmark for
professional competency.
SECTION ONE: QUESTIONS 1-160
1. A newborn with classic galactosemia is most likely deficient in
which enzyme?
A. Galactokinase
B. Galactose-1-phosphate uridyltransferase
C. Uridine diphosphate galactose-4-epimerase
D. Aldose reductase
B. Galactose-1-phosphate uridyltransferase
RATIONALE: Classic galactosemia is caused by deficiency of
galactose-1-phosphate uridyltransferase (GALT). Infants present
with jaundice, hepatomegaly, cataracts, and failure to thrive after
milk ingestion.
2. Which primary malignant brain tumor is most common in
adults?
A. Meningioma
B. Glioblastoma
C. Medulloblastoma
D. Ependymoma
B. Glioblastoma
, RATIONALE: Glioblastoma is the most common primary
malignant brain tumor in adults. It is a high-grade astrocytoma with
poor prognosis and characteristic necrosis and microvascular
proliferation.
3. Which osteopathic concept describes the inherent motion of
the central nervous system, cerebrospinal fluid, cranial bones,
and sacrum?
A. Somatic dysfunction
B. Primary respiratory mechanism
C. Viscerosomatic reflex
D. Facilitated segment
B. Primary respiratory mechanism
RATIONALE: The primary respiratory mechanism is a core
osteopathic concept involving the inherent motility of the brain and
spinal cord, cerebrospinal fluid, cranial bones, and sacrum.
4. Which antibiotic inhibits the 30S ribosomal subunit?
A. Erythromycin
B. Clindamycin
C. Tetracycline
D. Penicillin
C. Tetracycline
RATIONALE: Tetracyclines bind the 30S ribosomal subunit and
block aminoacyl-tRNA attachment, inhibiting protein synthesis.
5. The midgut is primarily supplied by which artery?
, A. Celiac trunk
B. Superior mesenteric artery
C. Inferior mesenteric artery
D. Internal iliac artery
B. Superior mesenteric artery
RATIONALE: The superior mesenteric artery supplies midgut
derivatives, from the distal duodenum to the proximal two-thirds of
the transverse colon.
6. Which area of the brain is responsible for language
comprehension?
A. Broca area
B. Wernicke area
C. Precentral gyrus
D. Postcentral gyrus
B. Wernicke area
RATIONALE: Wernicke area, located in the superior temporal
gyrus of the dominant hemisphere, is responsible for language
comprehension. Damage causes receptive aphasia.
7. Hyperacute rejection of a transplanted organ is mediated by:
A. Preformed recipient antibodies
B. T-cell-mediated cytotoxicity
C. Immune complex deposition
D. Delayed hypersensitivity
A. Preformed recipient antibodies
