Asu Bio 201 Exam And Correct Answers
With Rationales UPDATED 2026/2027 | A+
Guide
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 integrated understanding of human anatomy and physiology across all major organ
systems, emphasizing homeostatic regulation, cellular mechanisms, and clinical application of physiological
principles. It is designed to mirror the rigor of accredited US university examinations for pre-health majors.
STUDY GUIDE
Recommended duration: 3 hours. Passing target: 70% (C- equivalent; A+ requires 97%).
HIGHP - Page 1 of 46
,1. Which of the following best explains why a patient with a severe burn over 40% of body
surface area is at high risk for hypovolemic shock and infection?
[ ] A. Loss of epidermis increases vitamin D synthesis, leading to calcium imbalance and immune
suppression.
[ ] B. Destruction of dermal blood vessels and sweat glands causes massive fluid loss and loss of the
skin's barrier function.
[ ] C. Damage to the hypodermis reduces adipose storage, causing rapid weight loss and metabolic
acidosis.
[ ] D. Injury to hair follicles and nails impairs thermoregulation and sensory reception, leading to
systemic infection.
CORRECT: B. Destruction of dermal blood vessels and sweat glands causes massive fluid loss and
loss of the skin's barrier function.
The dermis contains blood vessels and sweat glands; their destruction leads to fluid loss and loss of barrier
immunity. The epidermis provides the primary barrier, but its loss alone does not explain hypovolemia.
Hypodermis and appendages contribute to insulation and sensation but are not the main causes of shock or
infection.
2. During a marathon, a runner's body temperature rises. Which set of responses is most
consistent with negative feedback regulation of body temperature?
[ ] A. Increased shivering and cutaneous vasoconstriction
[ ] B. Decreased sweat production and increased thyroxine release
[ ] C. Cutaneous vasodilation and increased sweat gland activity
[ ] D. Piloerection and increased skeletal muscle tone
CORRECT: C. Cutaneous vasodilation and increased sweat gland activity
Vasodilation and sweating promote heat loss, restoring normal temperature via negative feedback. Shivering,
vasoconstriction, piloerection, and increased thyroxine are heat-conserving or heat-generating responses to
cold, not heat.
3. A researcher applies a drug that blocks voltage-gated Na+ channels in a neuron. Which
phase of the action potential will be most directly affected?
[ ] A. Resting membrane potential
[ ] B. Depolarization phase
[ ] C. Repolarization phase
[ ] D. Hyperpolarization phase
CORRECT: B. Depolarization phase
Voltage-gated Na+ channels mediate the rapid influx of Na+ during depolarization. Repolarization depends on
K+ efflux, and hyperpolarization results from slow K+ channel closure. Resting potential is maintained by leak
channels and the Na+/K+ pump.
HIGHP - Page 2 of 46
,4. Which of the following correctly pairs a hormone with its primary effect on blood
glucose regulation?
[ ] A. Insulin - stimulates glycogenolysis in the liver
[ ] B. Glucagon - promotes gluconeogenesis and glycogenolysis
[ ] C. Cortisol - increases cellular glucose uptake
[ ] D. Epinephrine - inhibits lipolysis and promotes glycogenesis
CORRECT: B. Glucagon - promotes gluconeogenesis and glycogenolysis
Glucagon raises blood glucose by stimulating glycogen breakdown and glucose synthesis. Insulin promotes
glucose uptake and storage, not glycogenolysis. Cortisol raises glucose by promoting gluconeogenesis, and
epinephrine stimulates lipolysis and glycogenolysis.
5. A patient's lab results show elevated plasma osmolality and low blood volume. Which
hormone profile is most likely?
[ ] A. Decreased ADH and increased ANP
[ ] B. Increased ADH and increased aldosterone
[ ] C. Decreased aldosterone and increased ANP
[ ] D. Increased ANP and decreased ADH
CORRECT: B. Increased ADH and increased aldosterone
High osmolality stimulates ADH release to conserve water, and low blood volume triggers aldosterone to
retain Na+ and water. ANP is released in response to volume expansion, and decreased ADH would worsen
dehydration.
6. Which of the following best describes the role of the sarcoplasmic reticulum in skeletal
muscle contraction?
[ ] A. It stores acetylcholine for release at the neuromuscular junction.
[ ] B. It sequesters Ca2+ and releases it during excitation-contraction coupling.
[ ] C. It generates ATP through oxidative phosphorylation.
[ ] D. It anchors actin filaments to the Z-disc.
CORRECT: B. It sequesters Ca2+ and releases it during excitation-contraction coupling.
The sarcoplasmic reticulum stores and releases Ca2+ to trigger cross-bridge cycling. Acetylcholine is stored
in synaptic vesicles, ATP is produced in mitochondria, and actin anchoring involves Z-disc proteins like
-actinin.
7. In the cardiac cycle, which event occurs immediately after the QRS complex on an
ECG?
[ ] A. Atrial depolarization
[ ] B. Ventricular filling
HIGHP - Page 3 of 46
, [ ] C. Ventricular contraction
[ ] D. Closure of the semilunar valves
CORRECT: C. Ventricular contraction
The QRS complex represents ventricular depolarization, which is followed by ventricular contraction (systole).
Atrial depolarization is the P wave, ventricular filling occurs during diastole, and semilunar valve closure
marks the end of systole.
8. A patient with chronic obstructive pulmonary disease (COPD) has a blood gas showing
elevated CO2. Which compensatory mechanism is most likely?
[ ] A. Increased respiratory rate to blow off CO2
[ ] B. Renal retention of H+ and excretion of HCO3-
[ ] C. Renal excretion of H+ and reabsorption of HCO3-
[ ] D. Increased production of carbonic anhydrase in the lungs
CORRECT: C. Renal excretion of H+ and reabsorption of HCO3-
In chronic respiratory acidosis, the kidneys compensate by excreting H+ and reabsorbing HCO3- to raise pH.
Increased respiratory rate would help acutely but is often limited in COPD. Renal retention of H+ would
worsen acidosis.
9. Which of the following is a primary function of the loop of Henle in the nephron?
[ ] A. Filtration of blood plasma into the Bowman's capsule
[ ] B. Reabsorption of glucose and amino acids
[ ] C. Creation of a hyperosmotic medullary gradient for water reabsorption
[ ] D. Secretion of potassium and hydrogen ions
CORRECT: C. Creation of a hyperosmotic medullary gradient for water reabsorption
The loop of Henle establishes a concentration gradient in the medulla that allows water reabsorption from the
collecting duct. Filtration occurs in the glomerulus, glucose reabsorption in the proximal tubule, and K+/H+
secretion in the distal tubule and collecting duct.
10. During DNA replication, a mutation changes a template-strand adenine to guanine.
After two rounds of replication, what proportion of the resulting double helices will carry
the mutation?
[ ] A. All four helices
[ ] B. One of four helices
[ ] C. Two of four helices
[ ] D. Three of four helices
HIGHP - Page 4 of 46
With Rationales UPDATED 2026/2027 | A+
Guide
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 integrated understanding of human anatomy and physiology across all major organ
systems, emphasizing homeostatic regulation, cellular mechanisms, and clinical application of physiological
principles. It is designed to mirror the rigor of accredited US university examinations for pre-health majors.
STUDY GUIDE
Recommended duration: 3 hours. Passing target: 70% (C- equivalent; A+ requires 97%).
HIGHP - Page 1 of 46
,1. Which of the following best explains why a patient with a severe burn over 40% of body
surface area is at high risk for hypovolemic shock and infection?
[ ] A. Loss of epidermis increases vitamin D synthesis, leading to calcium imbalance and immune
suppression.
[ ] B. Destruction of dermal blood vessels and sweat glands causes massive fluid loss and loss of the
skin's barrier function.
[ ] C. Damage to the hypodermis reduces adipose storage, causing rapid weight loss and metabolic
acidosis.
[ ] D. Injury to hair follicles and nails impairs thermoregulation and sensory reception, leading to
systemic infection.
CORRECT: B. Destruction of dermal blood vessels and sweat glands causes massive fluid loss and
loss of the skin's barrier function.
The dermis contains blood vessels and sweat glands; their destruction leads to fluid loss and loss of barrier
immunity. The epidermis provides the primary barrier, but its loss alone does not explain hypovolemia.
Hypodermis and appendages contribute to insulation and sensation but are not the main causes of shock or
infection.
2. During a marathon, a runner's body temperature rises. Which set of responses is most
consistent with negative feedback regulation of body temperature?
[ ] A. Increased shivering and cutaneous vasoconstriction
[ ] B. Decreased sweat production and increased thyroxine release
[ ] C. Cutaneous vasodilation and increased sweat gland activity
[ ] D. Piloerection and increased skeletal muscle tone
CORRECT: C. Cutaneous vasodilation and increased sweat gland activity
Vasodilation and sweating promote heat loss, restoring normal temperature via negative feedback. Shivering,
vasoconstriction, piloerection, and increased thyroxine are heat-conserving or heat-generating responses to
cold, not heat.
3. A researcher applies a drug that blocks voltage-gated Na+ channels in a neuron. Which
phase of the action potential will be most directly affected?
[ ] A. Resting membrane potential
[ ] B. Depolarization phase
[ ] C. Repolarization phase
[ ] D. Hyperpolarization phase
CORRECT: B. Depolarization phase
Voltage-gated Na+ channels mediate the rapid influx of Na+ during depolarization. Repolarization depends on
K+ efflux, and hyperpolarization results from slow K+ channel closure. Resting potential is maintained by leak
channels and the Na+/K+ pump.
HIGHP - Page 2 of 46
,4. Which of the following correctly pairs a hormone with its primary effect on blood
glucose regulation?
[ ] A. Insulin - stimulates glycogenolysis in the liver
[ ] B. Glucagon - promotes gluconeogenesis and glycogenolysis
[ ] C. Cortisol - increases cellular glucose uptake
[ ] D. Epinephrine - inhibits lipolysis and promotes glycogenesis
CORRECT: B. Glucagon - promotes gluconeogenesis and glycogenolysis
Glucagon raises blood glucose by stimulating glycogen breakdown and glucose synthesis. Insulin promotes
glucose uptake and storage, not glycogenolysis. Cortisol raises glucose by promoting gluconeogenesis, and
epinephrine stimulates lipolysis and glycogenolysis.
5. A patient's lab results show elevated plasma osmolality and low blood volume. Which
hormone profile is most likely?
[ ] A. Decreased ADH and increased ANP
[ ] B. Increased ADH and increased aldosterone
[ ] C. Decreased aldosterone and increased ANP
[ ] D. Increased ANP and decreased ADH
CORRECT: B. Increased ADH and increased aldosterone
High osmolality stimulates ADH release to conserve water, and low blood volume triggers aldosterone to
retain Na+ and water. ANP is released in response to volume expansion, and decreased ADH would worsen
dehydration.
6. Which of the following best describes the role of the sarcoplasmic reticulum in skeletal
muscle contraction?
[ ] A. It stores acetylcholine for release at the neuromuscular junction.
[ ] B. It sequesters Ca2+ and releases it during excitation-contraction coupling.
[ ] C. It generates ATP through oxidative phosphorylation.
[ ] D. It anchors actin filaments to the Z-disc.
CORRECT: B. It sequesters Ca2+ and releases it during excitation-contraction coupling.
The sarcoplasmic reticulum stores and releases Ca2+ to trigger cross-bridge cycling. Acetylcholine is stored
in synaptic vesicles, ATP is produced in mitochondria, and actin anchoring involves Z-disc proteins like
-actinin.
7. In the cardiac cycle, which event occurs immediately after the QRS complex on an
ECG?
[ ] A. Atrial depolarization
[ ] B. Ventricular filling
HIGHP - Page 3 of 46
, [ ] C. Ventricular contraction
[ ] D. Closure of the semilunar valves
CORRECT: C. Ventricular contraction
The QRS complex represents ventricular depolarization, which is followed by ventricular contraction (systole).
Atrial depolarization is the P wave, ventricular filling occurs during diastole, and semilunar valve closure
marks the end of systole.
8. A patient with chronic obstructive pulmonary disease (COPD) has a blood gas showing
elevated CO2. Which compensatory mechanism is most likely?
[ ] A. Increased respiratory rate to blow off CO2
[ ] B. Renal retention of H+ and excretion of HCO3-
[ ] C. Renal excretion of H+ and reabsorption of HCO3-
[ ] D. Increased production of carbonic anhydrase in the lungs
CORRECT: C. Renal excretion of H+ and reabsorption of HCO3-
In chronic respiratory acidosis, the kidneys compensate by excreting H+ and reabsorbing HCO3- to raise pH.
Increased respiratory rate would help acutely but is often limited in COPD. Renal retention of H+ would
worsen acidosis.
9. Which of the following is a primary function of the loop of Henle in the nephron?
[ ] A. Filtration of blood plasma into the Bowman's capsule
[ ] B. Reabsorption of glucose and amino acids
[ ] C. Creation of a hyperosmotic medullary gradient for water reabsorption
[ ] D. Secretion of potassium and hydrogen ions
CORRECT: C. Creation of a hyperosmotic medullary gradient for water reabsorption
The loop of Henle establishes a concentration gradient in the medulla that allows water reabsorption from the
collecting duct. Filtration occurs in the glomerulus, glucose reabsorption in the proximal tubule, and K+/H+
secretion in the distal tubule and collecting duct.
10. During DNA replication, a mutation changes a template-strand adenine to guanine.
After two rounds of replication, what proportion of the resulting double helices will carry
the mutation?
[ ] A. All four helices
[ ] B. One of four helices
[ ] C. Two of four helices
[ ] D. Three of four helices
HIGHP - Page 4 of 46
