ASU BIO 201 EXAM AND CORRECT
ANSWERS WITH RATIONALES
Practice Question Bank & Answer Rationale
THIS PACK CONTAINS
147 exam-style multiple-choice questions. Each question includes the correct answer and a complete
rationale for focused revision.
COVERAGE
This exam assesses mastery of foundational human anatomy and physiology, covering histology, the
integumentary, skeletal, muscular, and nervous systems, with emphasis on structure-function relationships,
homeostasis, and clinical application. Questions require application-level reasoning and integration of multiple
concepts, consistent with ASU BIO 201 learning objectives.
STUDY GUIDE
Recommended duration: 2 hours 30 minutes. Passing target: 70% (35/50).
HIGHP - Page 1 of 48
,1. A tissue sample shows a single layer of flattened cells resting on a basement
membrane, with rapid diffusion of gases across it. Which epithelial classification best
matches this description?
[ ] A. Simple cuboidal epithelium
[ ] B. Simple squamous epithelium
[ ] C. Stratified squamous epithelium
[ ] D. Simple columnar epithelium
CORRECT: B. Simple squamous epithelium
Simple squamous epithelium consists of a single layer of flattened cells, ideal for diffusion and filtration (e.g.,
alveoli, endothelium). Simple cuboidal and columnar epithelia are thicker and more involved in
secretion/absorption, while stratified squamous is multilayered and protective, not optimized for rapid gas
exchange.
2. During a lab experiment, a drug blocks voltage-gated Na+ channels in a neuron. Which
phase of the action potential will be directly prevented?
[ ] A. Repolarization
[ ] B. Hyperpolarization
[ ] C. Depolarization
[ ] D. Resting membrane potential maintenance
CORRECT: C. Depolarization
Voltage-gated Na+ channels mediate the rapid influx of Na+ that causes depolarization. Repolarization
depends on K+ efflux, hyperpolarization on continued K+ permeability, and resting potential on Na+/K+
ATPase and leak channels, none of which are directly blocked by this drug.
3. Which statement best explains why bone is considered a dynamic tissue rather than a
static structure?
[ ] A. Bone matrix is entirely inorganic and never changes.
[ ] B. Osteoclasts and osteoblasts continuously remodel bone in response to stress and calcium
demand.
[ ] C. Chondrocytes replace osteocytes during growth.
[ ] D. Bone tissue lacks blood supply, limiting change.
CORRECT: B. Osteoclasts and osteoblasts continuously remodel bone in response to stress and
calcium demand.
Bone remodeling is an ongoing process where osteoclasts resorb and osteoblasts deposit bone, regulated by
mechanical stress, hormones, and calcium homeostasis. The other options incorrectly describe bone as inert,
confuse cell types, or deny its rich vascularity.
HIGHP - Page 2 of 48
,4. A muscle fiber is stimulated at a frequency that allows complete relaxation between
twitches, yet the force produced is gradually increasing. This phenomenon is best
described as:
[ ] A. Wave summation
[ ] B. Treppe (staircase effect)
[ ] C. Tetanus
[ ] D. Fatigue
CORRECT: B. Treppe (staircase effect)
Treppe is a gradual increase in twitch force when a muscle is stimulated repeatedly after full relaxation, likely
due to increased Ca2+ availability and warmth. Wave summation involves no full relaxation, tetanus is
sustained contraction without relaxation, and fatigue is a decline in force.
5. Which cranial nerve is primarily responsible for controlling the muscles of mastication?
[ ] A. Facial (VII)
[ ] B. Trigeminal (V)
[ ] C. Glossopharyngeal (IX)
[ ] D. Hypoglossal (XII)
CORRECT: B. Trigeminal (V)
The trigeminal nerve (CN V), specifically its mandibular division, innervates the muscles of mastication
(masseter, temporalis, pterygoids). The facial nerve controls facial expression, glossopharyngeal assists in
swallowing, and hypoglossal controls tongue movements.
6. In a negative feedback loop, which component detects the deviation from a set point
and sends input to the control center?
[ ] A. Effector
[ ] B. Receptor
[ ] C. Afferent pathway
[ ] D. Efferent pathway
CORRECT: B. Receptor
The receptor (sensor) monitors the internal environment and detects deviations from the set point, sending
signals to the control center. The effector produces the response, while afferent and efferent pathways are
the communication routes, not the detecting component.
7. Which layer of the epidermis is characterized by rapid cell division and is typically the
deepest epidermal layer?
[ ] A. Stratum corneum
[ ] B. Stratum lucidum
HIGHP - Page 3 of 48
, [ ] C. Stratum basale
[ ] D. Stratum granulosum
CORRECT: C. Stratum basale
The stratum basale is the deepest epidermal layer, containing stem cells that undergo mitosis to replenish
the epidermis. The stratum corneum is outermost and dead, stratum lucidum is only in thick skin, and stratum
granulosum is a middle layer where cells begin to die.
8. A patient has a tumor compressing the posterior pituitary. Which hormone secretion is
most likely to be directly affected?
[ ] A. Antidiuretic hormone (ADH)
[ ] B. Thyroid-stimulating hormone (TSH)
[ ] C. Adrenocorticotropic hormone (ACTH)
[ ] D. Growth hormone (GH)
CORRECT: A. Antidiuretic hormone (ADH)
The posterior pituitary stores and releases ADH and oxytocin, which are produced in the hypothalamus. TSH,
ACTH, and GH are secreted by the anterior pituitary, so a posterior pituitary tumor would not directly impair
their release.
9. Which of the following best describes the role of the sodium-potassium pump in
maintaining resting membrane potential?
[ ] A. It pumps 3 Na+ out and 2 K+ in, contributing to a negative interior.
[ ] B. It pumps 2 Na+ out and 3 K+ in, making the interior positive.
[ ] C. It pumps equal amounts of Na+ and K+ in opposite directions.
[ ] D. It has no effect on resting membrane potential.
CORRECT: A. It pumps 3 Na+ out and 2 K+ in, contributing to a negative interior.
The Na+/K+ ATPase exports three Na+ ions and imports two K+ ions per ATP, resulting in a net loss of
positive charge from the cell, contributing to the negative resting membrane potential. The other options
misstate the stoichiometry or deny its role.
10. During a lab on membrane transport, ouabain is added to a neuron. Which immediate
effect on the Na+/K+ ATPase is observed?
[ ] A. Increased K+ influx and Na+ efflux
[ ] B. Blockade of ATP hydrolysis and ion translocation
[ ] C. Reversal of the pump's stoichiometry
[ ] D. Enhanced secondary active transport of glucose
HIGHP - Page 4 of 48
ANSWERS WITH RATIONALES
Practice Question Bank & Answer Rationale
THIS PACK CONTAINS
147 exam-style multiple-choice questions. Each question includes the correct answer and a complete
rationale for focused revision.
COVERAGE
This exam assesses mastery of foundational human anatomy and physiology, covering histology, the
integumentary, skeletal, muscular, and nervous systems, with emphasis on structure-function relationships,
homeostasis, and clinical application. Questions require application-level reasoning and integration of multiple
concepts, consistent with ASU BIO 201 learning objectives.
STUDY GUIDE
Recommended duration: 2 hours 30 minutes. Passing target: 70% (35/50).
HIGHP - Page 1 of 48
,1. A tissue sample shows a single layer of flattened cells resting on a basement
membrane, with rapid diffusion of gases across it. Which epithelial classification best
matches this description?
[ ] A. Simple cuboidal epithelium
[ ] B. Simple squamous epithelium
[ ] C. Stratified squamous epithelium
[ ] D. Simple columnar epithelium
CORRECT: B. Simple squamous epithelium
Simple squamous epithelium consists of a single layer of flattened cells, ideal for diffusion and filtration (e.g.,
alveoli, endothelium). Simple cuboidal and columnar epithelia are thicker and more involved in
secretion/absorption, while stratified squamous is multilayered and protective, not optimized for rapid gas
exchange.
2. During a lab experiment, a drug blocks voltage-gated Na+ channels in a neuron. Which
phase of the action potential will be directly prevented?
[ ] A. Repolarization
[ ] B. Hyperpolarization
[ ] C. Depolarization
[ ] D. Resting membrane potential maintenance
CORRECT: C. Depolarization
Voltage-gated Na+ channels mediate the rapid influx of Na+ that causes depolarization. Repolarization
depends on K+ efflux, hyperpolarization on continued K+ permeability, and resting potential on Na+/K+
ATPase and leak channels, none of which are directly blocked by this drug.
3. Which statement best explains why bone is considered a dynamic tissue rather than a
static structure?
[ ] A. Bone matrix is entirely inorganic and never changes.
[ ] B. Osteoclasts and osteoblasts continuously remodel bone in response to stress and calcium
demand.
[ ] C. Chondrocytes replace osteocytes during growth.
[ ] D. Bone tissue lacks blood supply, limiting change.
CORRECT: B. Osteoclasts and osteoblasts continuously remodel bone in response to stress and
calcium demand.
Bone remodeling is an ongoing process where osteoclasts resorb and osteoblasts deposit bone, regulated by
mechanical stress, hormones, and calcium homeostasis. The other options incorrectly describe bone as inert,
confuse cell types, or deny its rich vascularity.
HIGHP - Page 2 of 48
,4. A muscle fiber is stimulated at a frequency that allows complete relaxation between
twitches, yet the force produced is gradually increasing. This phenomenon is best
described as:
[ ] A. Wave summation
[ ] B. Treppe (staircase effect)
[ ] C. Tetanus
[ ] D. Fatigue
CORRECT: B. Treppe (staircase effect)
Treppe is a gradual increase in twitch force when a muscle is stimulated repeatedly after full relaxation, likely
due to increased Ca2+ availability and warmth. Wave summation involves no full relaxation, tetanus is
sustained contraction without relaxation, and fatigue is a decline in force.
5. Which cranial nerve is primarily responsible for controlling the muscles of mastication?
[ ] A. Facial (VII)
[ ] B. Trigeminal (V)
[ ] C. Glossopharyngeal (IX)
[ ] D. Hypoglossal (XII)
CORRECT: B. Trigeminal (V)
The trigeminal nerve (CN V), specifically its mandibular division, innervates the muscles of mastication
(masseter, temporalis, pterygoids). The facial nerve controls facial expression, glossopharyngeal assists in
swallowing, and hypoglossal controls tongue movements.
6. In a negative feedback loop, which component detects the deviation from a set point
and sends input to the control center?
[ ] A. Effector
[ ] B. Receptor
[ ] C. Afferent pathway
[ ] D. Efferent pathway
CORRECT: B. Receptor
The receptor (sensor) monitors the internal environment and detects deviations from the set point, sending
signals to the control center. The effector produces the response, while afferent and efferent pathways are
the communication routes, not the detecting component.
7. Which layer of the epidermis is characterized by rapid cell division and is typically the
deepest epidermal layer?
[ ] A. Stratum corneum
[ ] B. Stratum lucidum
HIGHP - Page 3 of 48
, [ ] C. Stratum basale
[ ] D. Stratum granulosum
CORRECT: C. Stratum basale
The stratum basale is the deepest epidermal layer, containing stem cells that undergo mitosis to replenish
the epidermis. The stratum corneum is outermost and dead, stratum lucidum is only in thick skin, and stratum
granulosum is a middle layer where cells begin to die.
8. A patient has a tumor compressing the posterior pituitary. Which hormone secretion is
most likely to be directly affected?
[ ] A. Antidiuretic hormone (ADH)
[ ] B. Thyroid-stimulating hormone (TSH)
[ ] C. Adrenocorticotropic hormone (ACTH)
[ ] D. Growth hormone (GH)
CORRECT: A. Antidiuretic hormone (ADH)
The posterior pituitary stores and releases ADH and oxytocin, which are produced in the hypothalamus. TSH,
ACTH, and GH are secreted by the anterior pituitary, so a posterior pituitary tumor would not directly impair
their release.
9. Which of the following best describes the role of the sodium-potassium pump in
maintaining resting membrane potential?
[ ] A. It pumps 3 Na+ out and 2 K+ in, contributing to a negative interior.
[ ] B. It pumps 2 Na+ out and 3 K+ in, making the interior positive.
[ ] C. It pumps equal amounts of Na+ and K+ in opposite directions.
[ ] D. It has no effect on resting membrane potential.
CORRECT: A. It pumps 3 Na+ out and 2 K+ in, contributing to a negative interior.
The Na+/K+ ATPase exports three Na+ ions and imports two K+ ions per ATP, resulting in a net loss of
positive charge from the cell, contributing to the negative resting membrane potential. The other options
misstate the stoichiometry or deny its role.
10. During a lab on membrane transport, ouabain is added to a neuron. Which immediate
effect on the Na+/K+ ATPase is observed?
[ ] A. Increased K+ influx and Na+ efflux
[ ] B. Blockade of ATP hydrolysis and ion translocation
[ ] C. Reversal of the pump's stoichiometry
[ ] D. Enhanced secondary active transport of glucose
HIGHP - Page 4 of 48
