Ivy Tech APHY 101 Final Exam Actual Exam
2026/2027 – 100% Verified Answer Key
Included with Detailed Rationales – Pass
Guaranteed – A+ Graded
SECTION 1: Levels of Organization & Basic Chemistry (10 Questions)
Q1: A patient with chronic kidney disease has elevated blood urea nitrogen (BUN) levels.
Which level of biological organization does urea, a nitrogenous waste product, represent
when dissolved in blood plasma?
A. A tissue, because it is part of the fluid connective tissue blood
B. An organ, because the kidneys filter it from the blood
C. A chemical/molecular level, because urea is a small organic molecule dissolved in a
solution [CORRECT]
D. A cellular level, because it is produced by cellular metabolism
Correct Answer: C
Rationale: Urea (CH₄N₂O) is a molecular waste product, placing it at the chemical level
of organization. A is incorrect because urea itself is not a tissue—blood plasma is the
tissue component. B confuses the organ that processes urea with the level of
organization of urea itself. D incorrectly identifies the byproduct as the cellular level;
while cells produce urea, the molecule exists at the chemical level.
,Q2: During a metabolic acidosis, a patient's blood pH drops to 7.25. Which chemical
buffer system would respond FIRST to resist this pH change?
A. The phosphate buffer system, due to its high concentration in blood
B. The protein buffer system, primarily hemoglobin in red blood cells
C. The bicarbonate buffer system, because carbonic acid can donate H⁺ to raise pH
[CORRECT]
D. The nitrogenous buffer system involving ammonia and ammonium ions
Correct Answer: C
Rationale: The bicarbonate buffer system (H₂CO₃/HCO₃⁻) is the most rapid and
abundant blood buffer, responding within seconds to acid-base disturbances. A is
incorrect because the phosphate system is more important in intracellular and renal
buffering, not immediate blood pH defense. B operates but is slower and secondary to
bicarbonate. D is incorrect—ammonia buffering occurs primarily in the kidneys over
hours to days, not immediately.
Q3: A laboratory technician needs to prepare an isotonic saline solution for cell culture.
If normal human body cells have an intracellular solute concentration equivalent to 0.9%
NaCl, which solution would cause cells to swell and potentially burst?
A. 0.9% NaCl solution
B. 0.45% NaCl solution (half-normal saline) [CORRECT]
C. 5% dextrose in water (D5W)
D. 3% NaCl solution (hypertonic saline)
,Correct Answer: B
Rationale: 0.45% NaCl is hypotonic relative to intracellular fluid, causing water to move
into cells via osmosis, leading to swelling/lysis. A is isotonic and would maintain cell
volume. C (D5W) is actually isotonic initially though dextrose is metabolized. D is
hypertonic and would cause cell shrinkage (crenation), not swelling.
Q4: A patient presents with muscle weakness and cardiac arrhythmias. Laboratory
analysis reveals low potassium levels (hypokalemia). Which subatomic particle
imbalance is directly responsible for the electrical disturbances in excitable tissues?
A. Excess electrons causing negative charge buildup in the extracellular fluid
B. Deficient potassium ions (K⁺) affecting resting membrane potential [CORRECT]
C. Excess protons (H⁺) acidifying the intracellular environment
D. Deficient chloride ions (Cl⁻) disrupting action potential propagation
Correct Answer: B
Rationale: Potassium ions (K⁺) are the primary determinant of resting membrane
potential via the Nernst equation; hypokalemia hyperpolarizes cells, making excitation
more difficult and disrupting cardiac pacemaker activity. A confuses electron transfer in
chemical bonds with electrolyte physiology. C describes acidosis, not hypokalemia. D is
incorrect—chloride mainly affects inhibitory postsynaptic potentials, not the primary
cardiac excitability issue seen here.
Q5: An MRI technician explains that hydrogen atoms are used to create images because
they have an unpaired proton in their nucleus. What property of this subatomic particle
makes MRI possible?
, A. The proton's negative charge allows it to align with magnetic fields
B. The proton's spin generates a magnetic moment that responds to external magnetic
fields [CORRECT]
C. The proton's large mass compared to electrons creates tissue density contrast
D. The proton's ability to form covalent bonds with oxygen in water molecules
Correct Answer: B
Rationale: Protons possess "spin," creating a magnetic dipole moment that aligns with
or against MRI's strong external magnetic field; radiofrequency pulses then perturb this
alignment for imaging. A is incorrect—protons are positively charged. C confuses
atomic mass with imaging physics. D describes chemical bonding, not the magnetic
resonance phenomenon.
Q6: A patient with liver failure cannot synthesize adequate plasma proteins. Which
emergent property of life is most directly compromised when protein synthesis fails at
the organismal level?
A. Evolution, because protein mutations cannot occur without synthesis
B. Homeostasis, because proteins maintain pH, osmotic pressure, and transport
[CORRECT]
C. Growth, because proteins are only needed for cellular enlargement
D. Reproduction, because protein synthesis is exclusive to gamete production
Correct Answer: B
2026/2027 – 100% Verified Answer Key
Included with Detailed Rationales – Pass
Guaranteed – A+ Graded
SECTION 1: Levels of Organization & Basic Chemistry (10 Questions)
Q1: A patient with chronic kidney disease has elevated blood urea nitrogen (BUN) levels.
Which level of biological organization does urea, a nitrogenous waste product, represent
when dissolved in blood plasma?
A. A tissue, because it is part of the fluid connective tissue blood
B. An organ, because the kidneys filter it from the blood
C. A chemical/molecular level, because urea is a small organic molecule dissolved in a
solution [CORRECT]
D. A cellular level, because it is produced by cellular metabolism
Correct Answer: C
Rationale: Urea (CH₄N₂O) is a molecular waste product, placing it at the chemical level
of organization. A is incorrect because urea itself is not a tissue—blood plasma is the
tissue component. B confuses the organ that processes urea with the level of
organization of urea itself. D incorrectly identifies the byproduct as the cellular level;
while cells produce urea, the molecule exists at the chemical level.
,Q2: During a metabolic acidosis, a patient's blood pH drops to 7.25. Which chemical
buffer system would respond FIRST to resist this pH change?
A. The phosphate buffer system, due to its high concentration in blood
B. The protein buffer system, primarily hemoglobin in red blood cells
C. The bicarbonate buffer system, because carbonic acid can donate H⁺ to raise pH
[CORRECT]
D. The nitrogenous buffer system involving ammonia and ammonium ions
Correct Answer: C
Rationale: The bicarbonate buffer system (H₂CO₃/HCO₃⁻) is the most rapid and
abundant blood buffer, responding within seconds to acid-base disturbances. A is
incorrect because the phosphate system is more important in intracellular and renal
buffering, not immediate blood pH defense. B operates but is slower and secondary to
bicarbonate. D is incorrect—ammonia buffering occurs primarily in the kidneys over
hours to days, not immediately.
Q3: A laboratory technician needs to prepare an isotonic saline solution for cell culture.
If normal human body cells have an intracellular solute concentration equivalent to 0.9%
NaCl, which solution would cause cells to swell and potentially burst?
A. 0.9% NaCl solution
B. 0.45% NaCl solution (half-normal saline) [CORRECT]
C. 5% dextrose in water (D5W)
D. 3% NaCl solution (hypertonic saline)
,Correct Answer: B
Rationale: 0.45% NaCl is hypotonic relative to intracellular fluid, causing water to move
into cells via osmosis, leading to swelling/lysis. A is isotonic and would maintain cell
volume. C (D5W) is actually isotonic initially though dextrose is metabolized. D is
hypertonic and would cause cell shrinkage (crenation), not swelling.
Q4: A patient presents with muscle weakness and cardiac arrhythmias. Laboratory
analysis reveals low potassium levels (hypokalemia). Which subatomic particle
imbalance is directly responsible for the electrical disturbances in excitable tissues?
A. Excess electrons causing negative charge buildup in the extracellular fluid
B. Deficient potassium ions (K⁺) affecting resting membrane potential [CORRECT]
C. Excess protons (H⁺) acidifying the intracellular environment
D. Deficient chloride ions (Cl⁻) disrupting action potential propagation
Correct Answer: B
Rationale: Potassium ions (K⁺) are the primary determinant of resting membrane
potential via the Nernst equation; hypokalemia hyperpolarizes cells, making excitation
more difficult and disrupting cardiac pacemaker activity. A confuses electron transfer in
chemical bonds with electrolyte physiology. C describes acidosis, not hypokalemia. D is
incorrect—chloride mainly affects inhibitory postsynaptic potentials, not the primary
cardiac excitability issue seen here.
Q5: An MRI technician explains that hydrogen atoms are used to create images because
they have an unpaired proton in their nucleus. What property of this subatomic particle
makes MRI possible?
, A. The proton's negative charge allows it to align with magnetic fields
B. The proton's spin generates a magnetic moment that responds to external magnetic
fields [CORRECT]
C. The proton's large mass compared to electrons creates tissue density contrast
D. The proton's ability to form covalent bonds with oxygen in water molecules
Correct Answer: B
Rationale: Protons possess "spin," creating a magnetic dipole moment that aligns with
or against MRI's strong external magnetic field; radiofrequency pulses then perturb this
alignment for imaging. A is incorrect—protons are positively charged. C confuses
atomic mass with imaging physics. D describes chemical bonding, not the magnetic
resonance phenomenon.
Q6: A patient with liver failure cannot synthesize adequate plasma proteins. Which
emergent property of life is most directly compromised when protein synthesis fails at
the organismal level?
A. Evolution, because protein mutations cannot occur without synthesis
B. Homeostasis, because proteins maintain pH, osmotic pressure, and transport
[CORRECT]
C. Growth, because proteins are only needed for cellular enlargement
D. Reproduction, because protein synthesis is exclusive to gamete production
Correct Answer: B
