HESI A2 ANATOMY & PHYSIOLOGY (TEST
BANK) — 260 EXAM PREP QUESTIONS,
ANSWERS & RATIONALES | 2026
Topics covered: Cell Biology, Integumentary, Skeletal, Muscular, Nervous, Cardiovascular,
Respiratory, Digestive, Urinary, Endocrine, Reproductive, Lymphatic/Immune, Special Senses,
and Acid-Base Balance.
SECTION 1: CELL BIOLOGY & BASIC CHEMISTRY (Questions 1–20)
1. Which organelle is responsible for producing ATP through cellular respiration?
A) Ribosome B) Golgi apparatus C) Mitochondria (correct answer) D) Lysosome
Rationale: The mitochondria are the "powerhouse of the cell," generating ATP via
oxidative phosphorylation during cellular respiration. All other organelles listed serve
different functions.
2. Which process moves water across a semipermeable membrane from an area of low
solute concentration to high solute concentration?
A) Active transport B) Facilitated diffusion C) Filtration D) Osmosis (correct answer)
Rationale: Osmosis is the passive movement of water across a semipermeable membrane
toward the area of higher solute concentration, requiring no energy input.
,3. The cell membrane is primarily composed of:
A) Proteins and carbohydrates B) Carbohydrates and cholesterol C) Phospholipids and proteins
(correct answer) D) Glycoproteins and nucleic acids
Rationale: The fluid mosaic model describes the cell membrane as a phospholipid bilayer
embedded with proteins. The phospholipid heads are hydrophilic and the tails are
hydrophobic, creating a selectively permeable barrier.
4. Which type of cellular transport requires energy (ATP)?
A) Simple diffusion B) Osmosis C) Facilitated diffusion D) Active transport (correct answer)
Rationale: Active transport moves substances against their concentration gradient and
requires ATP. Simple diffusion, osmosis, and facilitated diffusion are all passive processes
that do not require energy.
5. Which phase of mitosis involves the chromosomes lining up at the cell's equator?
A) Prophase B) Anaphase C) Metaphase (correct answer) D) Telophase
Rationale: During metaphase, chromosomes align along the metaphase plate (cell equator).
This alignment ensures each daughter cell receives an equal and correct number of
chromosomes.
6. DNA replication occurs during which phase of the cell cycle?
,A) G1 phase B) S phase (correct answer) C) G2 phase D) M phase
Rationale: The S (synthesis) phase is when DNA is replicated in preparation for cell
division. G1 and G2 are growth phases; the M phase is when mitosis/meiosis occurs.
7. Which organelle is responsible for protein synthesis?
A) Mitochondria B) Lysosome C) Ribosome (correct answer) D) Vacuole
Rationale: Ribosomes translate mRNA into proteins. They can be free-floating in the
cytoplasm or attached to the rough endoplasmic reticulum.
8. The Golgi apparatus is primarily responsible for:
A) Energy production B) DNA storage C) Processing and packaging proteins (correct
answer) D) Lipid synthesis
Rationale: The Golgi apparatus modifies, sorts, and packages proteins and lipids for
transport to their final destinations inside or outside the cell.
9. A solution that causes cells to shrink due to water loss is called:
A) Hypotonic B) Isotonic C) Hypertonic (correct answer) D) Isometric
Rationale: A hypertonic solution has a higher solute concentration than the cell. Water
moves out of the cell by osmosis, causing the cell to shrink (crenation in red blood cells).
10. Which cellular structure contains the cell's genetic information?
, A) Cytoplasm B) Nucleus (correct answer) C) Ribosome D) Mitochondria
Rationale: The nucleus houses the cell's DNA organized into chromosomes. It controls gene
expression and directs cellular activities.
11. Which type of tissue covers body surfaces and lines internal organs?
A) Connective tissue B) Muscle tissue C) Nervous tissue D) Epithelial tissue (correct answer)
Rationale: Epithelial tissue forms coverings and linings throughout the body, including the
skin, digestive tract, and blood vessels. It serves protective, secretory, and absorptive
functions.
12. Lysosomes contain enzymes used for:
A) Protein synthesis B) Energy production C) Digestion of cellular waste and foreign
materials (correct answer) D) DNA replication
Rationale: Lysosomes are the cell's "digestive system," containing hydrolytic enzymes that
break down worn-out organelles, foreign substances, and cellular debris.
13. Which of the following best describes a isotonic solution?
A) It has fewer solutes than the cell B) It has more solutes than the cell C) It has the same
solute concentration as the cell (correct answer) D) It causes cells to burst
Rationale: In an isotonic solution, there is no net movement of water into or out of the cell
because the concentration of solutes is equal on both sides of the membrane.
BANK) — 260 EXAM PREP QUESTIONS,
ANSWERS & RATIONALES | 2026
Topics covered: Cell Biology, Integumentary, Skeletal, Muscular, Nervous, Cardiovascular,
Respiratory, Digestive, Urinary, Endocrine, Reproductive, Lymphatic/Immune, Special Senses,
and Acid-Base Balance.
SECTION 1: CELL BIOLOGY & BASIC CHEMISTRY (Questions 1–20)
1. Which organelle is responsible for producing ATP through cellular respiration?
A) Ribosome B) Golgi apparatus C) Mitochondria (correct answer) D) Lysosome
Rationale: The mitochondria are the "powerhouse of the cell," generating ATP via
oxidative phosphorylation during cellular respiration. All other organelles listed serve
different functions.
2. Which process moves water across a semipermeable membrane from an area of low
solute concentration to high solute concentration?
A) Active transport B) Facilitated diffusion C) Filtration D) Osmosis (correct answer)
Rationale: Osmosis is the passive movement of water across a semipermeable membrane
toward the area of higher solute concentration, requiring no energy input.
,3. The cell membrane is primarily composed of:
A) Proteins and carbohydrates B) Carbohydrates and cholesterol C) Phospholipids and proteins
(correct answer) D) Glycoproteins and nucleic acids
Rationale: The fluid mosaic model describes the cell membrane as a phospholipid bilayer
embedded with proteins. The phospholipid heads are hydrophilic and the tails are
hydrophobic, creating a selectively permeable barrier.
4. Which type of cellular transport requires energy (ATP)?
A) Simple diffusion B) Osmosis C) Facilitated diffusion D) Active transport (correct answer)
Rationale: Active transport moves substances against their concentration gradient and
requires ATP. Simple diffusion, osmosis, and facilitated diffusion are all passive processes
that do not require energy.
5. Which phase of mitosis involves the chromosomes lining up at the cell's equator?
A) Prophase B) Anaphase C) Metaphase (correct answer) D) Telophase
Rationale: During metaphase, chromosomes align along the metaphase plate (cell equator).
This alignment ensures each daughter cell receives an equal and correct number of
chromosomes.
6. DNA replication occurs during which phase of the cell cycle?
,A) G1 phase B) S phase (correct answer) C) G2 phase D) M phase
Rationale: The S (synthesis) phase is when DNA is replicated in preparation for cell
division. G1 and G2 are growth phases; the M phase is when mitosis/meiosis occurs.
7. Which organelle is responsible for protein synthesis?
A) Mitochondria B) Lysosome C) Ribosome (correct answer) D) Vacuole
Rationale: Ribosomes translate mRNA into proteins. They can be free-floating in the
cytoplasm or attached to the rough endoplasmic reticulum.
8. The Golgi apparatus is primarily responsible for:
A) Energy production B) DNA storage C) Processing and packaging proteins (correct
answer) D) Lipid synthesis
Rationale: The Golgi apparatus modifies, sorts, and packages proteins and lipids for
transport to their final destinations inside or outside the cell.
9. A solution that causes cells to shrink due to water loss is called:
A) Hypotonic B) Isotonic C) Hypertonic (correct answer) D) Isometric
Rationale: A hypertonic solution has a higher solute concentration than the cell. Water
moves out of the cell by osmosis, causing the cell to shrink (crenation in red blood cells).
10. Which cellular structure contains the cell's genetic information?
, A) Cytoplasm B) Nucleus (correct answer) C) Ribosome D) Mitochondria
Rationale: The nucleus houses the cell's DNA organized into chromosomes. It controls gene
expression and directs cellular activities.
11. Which type of tissue covers body surfaces and lines internal organs?
A) Connective tissue B) Muscle tissue C) Nervous tissue D) Epithelial tissue (correct answer)
Rationale: Epithelial tissue forms coverings and linings throughout the body, including the
skin, digestive tract, and blood vessels. It serves protective, secretory, and absorptive
functions.
12. Lysosomes contain enzymes used for:
A) Protein synthesis B) Energy production C) Digestion of cellular waste and foreign
materials (correct answer) D) DNA replication
Rationale: Lysosomes are the cell's "digestive system," containing hydrolytic enzymes that
break down worn-out organelles, foreign substances, and cellular debris.
13. Which of the following best describes a isotonic solution?
A) It has fewer solutes than the cell B) It has more solutes than the cell C) It has the same
solute concentration as the cell (correct answer) D) It causes cells to burst
Rationale: In an isotonic solution, there is no net movement of water into or out of the cell
because the concentration of solutes is equal on both sides of the membrane.
