PAVE QUALIFYING SCIENCE EXAM
(QSE) COMPREHENSIVE REVIEW
QUESTIONS AND DETAILED
SOLUTIONS LATEST UPDATE
1. Which of the following enzymes is responsible for the rate-limiting step in the process of
glycolysis?
A. Hexokinase
B. Pyruvate kinase
C. Phosphofructokinase-1
D. Glucose-6-phosphatase
Answer: C
Conceptual Explanation: Phosphofructokinase-1 (PFK-1) is the key regulatory and rate-
limiting enzyme of glycolysis, catalyzing the conversion of fructose-6-phosphate to
fructose-1,6-bisphosphate.
2. In the mammalian heart, which structure is the primary pacemaker under normal
physiological conditions?
A. Atrioventricular (AV) node
B. Bundle of His
,C. Purkinje fibers
D. Sinoatrial (SA) node
Answer: D
Conceptual Explanation: The sinoatrial node, located in the right atrium, has the fastest
spontaneous depolarization rate and initiates the cardiac cycle.
3. Which pharmacological agent is a competitive antagonist of the muscarinic acetylcholine
receptors and is used to treat organophosphate toxicity?
A. Atropine
B. Pralidoxime (2-PAM)
C. Neostigmine
D. Physostigmine
Answer: A
Conceptual Explanation: Atropine blocks muscarinic receptors to counteract cholinergic
crises, while 2-PAM is used to regenerate acetylcholinesterase.
4. A histology slide shows ‘owl-eye’ inclusion bodies in cells. Which virus is most likely
associated with this finding?
A. Parvovirus
B. Herpesvirus
C. Poxvirus
, D. Cytomegalovirus
Answer: D
Conceptual Explanation: Large intranuclear inclusion bodies surrounded by a clear halo
(owl-eye) are characteristic of Cytomegalovirus (a beta-herpesvirus) infections.
5. In the canine, which parasite is transmitted through the ingestion of an infected flea
(Ctenocephalides felis)?
A. Toxocara canis
B. Dipylidium caninum
C. Ancylostoma caninum
D. Trichuris vulpis
Answer: B
Conceptual Explanation: Dipylidium caninum, the double-pored tapeworm, uses the flea
as an intermediate host; dogs are infected by ingesting the flea containing cysticercoids.
6. Which type of necrosis is most characteristic of central nervous system (CNS) injury, such as
a brain infarct?
A. Coagulative necrosis
B. Caseous necrosis
C. Liquefactive necrosis
D. Fat necrosis
(QSE) COMPREHENSIVE REVIEW
QUESTIONS AND DETAILED
SOLUTIONS LATEST UPDATE
1. Which of the following enzymes is responsible for the rate-limiting step in the process of
glycolysis?
A. Hexokinase
B. Pyruvate kinase
C. Phosphofructokinase-1
D. Glucose-6-phosphatase
Answer: C
Conceptual Explanation: Phosphofructokinase-1 (PFK-1) is the key regulatory and rate-
limiting enzyme of glycolysis, catalyzing the conversion of fructose-6-phosphate to
fructose-1,6-bisphosphate.
2. In the mammalian heart, which structure is the primary pacemaker under normal
physiological conditions?
A. Atrioventricular (AV) node
B. Bundle of His
,C. Purkinje fibers
D. Sinoatrial (SA) node
Answer: D
Conceptual Explanation: The sinoatrial node, located in the right atrium, has the fastest
spontaneous depolarization rate and initiates the cardiac cycle.
3. Which pharmacological agent is a competitive antagonist of the muscarinic acetylcholine
receptors and is used to treat organophosphate toxicity?
A. Atropine
B. Pralidoxime (2-PAM)
C. Neostigmine
D. Physostigmine
Answer: A
Conceptual Explanation: Atropine blocks muscarinic receptors to counteract cholinergic
crises, while 2-PAM is used to regenerate acetylcholinesterase.
4. A histology slide shows ‘owl-eye’ inclusion bodies in cells. Which virus is most likely
associated with this finding?
A. Parvovirus
B. Herpesvirus
C. Poxvirus
, D. Cytomegalovirus
Answer: D
Conceptual Explanation: Large intranuclear inclusion bodies surrounded by a clear halo
(owl-eye) are characteristic of Cytomegalovirus (a beta-herpesvirus) infections.
5. In the canine, which parasite is transmitted through the ingestion of an infected flea
(Ctenocephalides felis)?
A. Toxocara canis
B. Dipylidium caninum
C. Ancylostoma caninum
D. Trichuris vulpis
Answer: B
Conceptual Explanation: Dipylidium caninum, the double-pored tapeworm, uses the flea
as an intermediate host; dogs are infected by ingesting the flea containing cysticercoids.
6. Which type of necrosis is most characteristic of central nervous system (CNS) injury, such as
a brain infarct?
A. Coagulative necrosis
B. Caseous necrosis
C. Liquefactive necrosis
D. Fat necrosis
