HESI A2 Anatomy & Physiology Exam
2025/2026 – Full Verified Questions with
Correct Answers
Question 1: Cellular Physiology - Plasma Membrane
The plasma membrane of a cell is primarily composed of which structure that allows selective
permeability?
A. Phospholipid bilayer with embedded proteins.
B. Rigid cellulose wall.
C. Protein matrix with lipid droplets.
D. Nucleic acid chains.
A. Phospholipid bilayer with embedded proteins.
Strong Rationale: The fluid mosaic model describes the plasma membrane as a dynamic phospholipid
bilayer with integral proteins for transport, receptors, and channels, enabling selective permeability via
passive diffusion, facilitated transport, and active mechanisms. This principle is crucial for understanding
drug absorption in nursing, such as lipid-soluble medications crossing membranes more readily per APS
2025 cellular transport guidelines.
Question 2: Cellular Physiology - Osmosis
A patient receives an IV solution that is hypotonic to red blood cells, causing them to swell. This process
is known as?
A. Diffusion.
B. Osmosis.
C. Active transport.
D. Facilitated diffusion.
B. Osmosis.
,Strong Rationale: Osmosis is the passive movement of water across a semipermeable membrane from
low to high solute concentration, leading to cell swelling in hypotonic solutions (e.g., 0.45% NaCl).
Clinically, nurses monitor for hemolysis in hypotonic IVs to prevent complications like cerebral edema,
aligning with NBME 2025 fluid balance standards.
Question 3: Cellular Physiology - Mitosis
During mitosis, which phase involves the separation of sister chromatids to opposite poles?
A. Prophase.
B. Metaphase.
C. Anaphase.
D. Telophase.
C. Anaphase.
Strong Rationale: Anaphase is characterized by spindle fibers pulling chromatids apart, ensuring equal
DNA distribution for genetic stability. In nursing, understanding mitosis aids in explaining chemotherapy
effects (e.g., mitotic inhibitors like vincristine) that target this phase to halt cancer cell proliferation, per
APS 2025 cell cycle therapeutics.
Question 4: Cellular Physiology - ATP Production
The primary site of ATP production via oxidative phosphorylation in eukaryotic cells is?
A. Nucleus.
B. Ribosomes.
C. Mitochondria.
D. Golgi apparatus.
C. Mitochondria.
Strong Rationale: Mitochondria, the "powerhouses," house the electron transport chain in the inner
membrane, generating ~90% of ATP from glucose oxidation. Nurses apply this to assess fatigue in
mitochondrial disorders or during sepsis, where ATP depletion impairs organ function, as per NBME
2025 bioenergetics.
Question 5: Cellular Physiology - Endocytosis
,A white blood cell engulfing a bacterium uses which process to internalize it?
A. Exocytosis.
B. Phagocytosis.
C. Pinocytosis.
D. Receptor-mediated endocytosis.
B. Phagocytosis.
Strong Rationale: Phagocytosis is a form of endocytosis where large particles (e.g., bacteria) are
engulfed by pseudopodia, forming a phagosome that fuses with lysosomes for digestion. This innate
immune mechanism is vital for infection control; nurses monitor phagocytosis in immunocompromised
patients to prevent sepsis, per APS 2025 immune physiology.
Question 6: Cellular Physiology - Protein Synthesis
The process where mRNA is translated into a polypeptide chain occurs at the?
A. Nucleus.
B. Cytoplasm ribosomes.
C. Lysosomes.
D. Peroxisomes.
B. Cytoplasm ribosomes.
Strong Rationale: Translation at ribosomes decodes mRNA codons into amino acid sequences via tRNA,
forming proteins essential for cellular function. In clinical practice, disruptions (e.g., in genetic disorders)
inform nursing care for protein malabsorption syndromes like kwashiorkor, per NBME 2025 molecular
biology.
Question 7: Cellular Physiology - Hypertonic Solution
Exposure of cells to a hypertonic solution causes water to move out, leading to?
A. Cell lysis.
B. Crenation.
C. Turgor.
D. Swelling.
B. Crenation.
, Strong Rationale: In hypertonic solutions, osmosis draws water out, shrinking cells and forming
crenations (scalloped edges) in RBCs. Nurses use hypertonic saline (3% NaCl) judiciously to treat
hyponatremia, monitoring for dehydration risks as per APS 2025 osmotic balance guidelines.
Question 8: Cellular Physiology - DNA Replication
The enzyme that unwinds the DNA double helix during replication is?
A. DNA polymerase.
B. Helicase.
C. Ligase.
D. Primase.
B. Helicase.
Strong Rationale: Helicase breaks hydrogen bonds, creating replication forks for semi-conservative
DNA synthesis. Accurate replication prevents mutations; nurses educate on UV protection to reduce skin
cancer risk from replication errors, per NBME 2025 genetics.
Question 9: Cellular Physiology - Lysosomes
Lysosomes function primarily in?
A. Protein synthesis.
B. Intracellular digestion.
C. Energy production.
D. Lipid storage.
B. Intracellular digestion.
Strong Rationale: Lysosomes contain hydrolytic enzymes that break down macromolecules, organelles,
and pathogens in acidic pH. Deficiencies (e.g., Tay-Sachs) cause lysosomal storage diseases; nurses
monitor for neurological symptoms in affected pediatrics, per APS 2025 organelle functions.
Question 10: Cellular Physiology - Sodium-Potassium Pump
The Na+/K+ ATPase pump maintains resting membrane potential by transporting?
2025/2026 – Full Verified Questions with
Correct Answers
Question 1: Cellular Physiology - Plasma Membrane
The plasma membrane of a cell is primarily composed of which structure that allows selective
permeability?
A. Phospholipid bilayer with embedded proteins.
B. Rigid cellulose wall.
C. Protein matrix with lipid droplets.
D. Nucleic acid chains.
A. Phospholipid bilayer with embedded proteins.
Strong Rationale: The fluid mosaic model describes the plasma membrane as a dynamic phospholipid
bilayer with integral proteins for transport, receptors, and channels, enabling selective permeability via
passive diffusion, facilitated transport, and active mechanisms. This principle is crucial for understanding
drug absorption in nursing, such as lipid-soluble medications crossing membranes more readily per APS
2025 cellular transport guidelines.
Question 2: Cellular Physiology - Osmosis
A patient receives an IV solution that is hypotonic to red blood cells, causing them to swell. This process
is known as?
A. Diffusion.
B. Osmosis.
C. Active transport.
D. Facilitated diffusion.
B. Osmosis.
,Strong Rationale: Osmosis is the passive movement of water across a semipermeable membrane from
low to high solute concentration, leading to cell swelling in hypotonic solutions (e.g., 0.45% NaCl).
Clinically, nurses monitor for hemolysis in hypotonic IVs to prevent complications like cerebral edema,
aligning with NBME 2025 fluid balance standards.
Question 3: Cellular Physiology - Mitosis
During mitosis, which phase involves the separation of sister chromatids to opposite poles?
A. Prophase.
B. Metaphase.
C. Anaphase.
D. Telophase.
C. Anaphase.
Strong Rationale: Anaphase is characterized by spindle fibers pulling chromatids apart, ensuring equal
DNA distribution for genetic stability. In nursing, understanding mitosis aids in explaining chemotherapy
effects (e.g., mitotic inhibitors like vincristine) that target this phase to halt cancer cell proliferation, per
APS 2025 cell cycle therapeutics.
Question 4: Cellular Physiology - ATP Production
The primary site of ATP production via oxidative phosphorylation in eukaryotic cells is?
A. Nucleus.
B. Ribosomes.
C. Mitochondria.
D. Golgi apparatus.
C. Mitochondria.
Strong Rationale: Mitochondria, the "powerhouses," house the electron transport chain in the inner
membrane, generating ~90% of ATP from glucose oxidation. Nurses apply this to assess fatigue in
mitochondrial disorders or during sepsis, where ATP depletion impairs organ function, as per NBME
2025 bioenergetics.
Question 5: Cellular Physiology - Endocytosis
,A white blood cell engulfing a bacterium uses which process to internalize it?
A. Exocytosis.
B. Phagocytosis.
C. Pinocytosis.
D. Receptor-mediated endocytosis.
B. Phagocytosis.
Strong Rationale: Phagocytosis is a form of endocytosis where large particles (e.g., bacteria) are
engulfed by pseudopodia, forming a phagosome that fuses with lysosomes for digestion. This innate
immune mechanism is vital for infection control; nurses monitor phagocytosis in immunocompromised
patients to prevent sepsis, per APS 2025 immune physiology.
Question 6: Cellular Physiology - Protein Synthesis
The process where mRNA is translated into a polypeptide chain occurs at the?
A. Nucleus.
B. Cytoplasm ribosomes.
C. Lysosomes.
D. Peroxisomes.
B. Cytoplasm ribosomes.
Strong Rationale: Translation at ribosomes decodes mRNA codons into amino acid sequences via tRNA,
forming proteins essential for cellular function. In clinical practice, disruptions (e.g., in genetic disorders)
inform nursing care for protein malabsorption syndromes like kwashiorkor, per NBME 2025 molecular
biology.
Question 7: Cellular Physiology - Hypertonic Solution
Exposure of cells to a hypertonic solution causes water to move out, leading to?
A. Cell lysis.
B. Crenation.
C. Turgor.
D. Swelling.
B. Crenation.
, Strong Rationale: In hypertonic solutions, osmosis draws water out, shrinking cells and forming
crenations (scalloped edges) in RBCs. Nurses use hypertonic saline (3% NaCl) judiciously to treat
hyponatremia, monitoring for dehydration risks as per APS 2025 osmotic balance guidelines.
Question 8: Cellular Physiology - DNA Replication
The enzyme that unwinds the DNA double helix during replication is?
A. DNA polymerase.
B. Helicase.
C. Ligase.
D. Primase.
B. Helicase.
Strong Rationale: Helicase breaks hydrogen bonds, creating replication forks for semi-conservative
DNA synthesis. Accurate replication prevents mutations; nurses educate on UV protection to reduce skin
cancer risk from replication errors, per NBME 2025 genetics.
Question 9: Cellular Physiology - Lysosomes
Lysosomes function primarily in?
A. Protein synthesis.
B. Intracellular digestion.
C. Energy production.
D. Lipid storage.
B. Intracellular digestion.
Strong Rationale: Lysosomes contain hydrolytic enzymes that break down macromolecules, organelles,
and pathogens in acidic pH. Deficiencies (e.g., Tay-Sachs) cause lysosomal storage diseases; nurses
monitor for neurological symptoms in affected pediatrics, per APS 2025 organelle functions.
Question 10: Cellular Physiology - Sodium-Potassium Pump
The Na+/K+ ATPase pump maintains resting membrane potential by transporting?
