HESI A2 Biology Exam Actual Exam
2026/2027 | Actual Questions and Answers
| Complete Test | Pass Guaranteed - A+
Graded
Cell Biology & Cellular Processes
Q1: You are viewing a cell under a microscope and observe that it lacks a nucleus and
membrane-bound organelles. Based on this observation, how would you classify this
cell?
A. Eukaryotic cell
B. Prokaryotic cell [CORRECT]
C. Animal cell
D. Plant cell
Correct Answer: B
Rationale: Prokaryotic cells are characterized by the absence of a true nucleus and
membrane-bound organelles, distinguishing them from eukaryotic cells which possess
both.
Q2: If a cell requires a significant amount of energy to perform active transport, which
organelle would be most abundant in that cell?
A. Nucleus
B. Ribosome
C. Mitochondria [CORRECT]
D. Golgi apparatus
Correct Answer: C
Rationale: Mitochondria are the sites of aerobic cellular respiration and generate ATP
(energy), so cells with high energy demands (like those using active transport) have
many mitochondria.
Q3: Which component of the cell membrane is primarily responsible for controlling what
enters and exits the cell?
A. Phospholipid bilayer
B. Cholesterol
C. Proteins [CORRECT]
, D. Carbohydrates
Correct Answer: C
Rationale: While the phospholipid bilayer provides the basic structure, membrane
proteins (channels, pumps, and carriers) are specifically responsible for regulating the
transport of substances across the membrane.
Q4: A red blood cell is placed in a beaker of pure water. What will happen to the cell,
and what is this process called?
A. The cell will shrink (crenate) due to osmosis.
B. The cell will swell and possibly burst (lyse) due to osmosis. [CORRECT]
C. The cell will remain the same size due to diffusion.
D. The cell will shrink due to active transport.
Correct Answer: B
Rationale: Pure water is a hypotonic solution relative to the cell's cytoplasm, causing
water to move into the cell via osmosis, leading to swelling and potential bursting (lysis).
Q5: During the process of cellular respiration, which molecule is broken down to release
energy in the form of ATP?
A. Carbon dioxide
B. Water
C. Glucose [CORRECT]
D. Oxygen
Correct Answer: C
Rationale: Glucose is the primary fuel molecule broken down during glycolysis, the
Krebs cycle, and the electron transport chain to produce ATP.
Q6: In which phase of cellular respiration is the majority of ATP produced?
A. Glycolysis
B. Krebs Cycle (Citric Acid Cycle)
C. Electron Transport Chain [CORRECT]
D. Fermentation
Correct Answer: C
Rationale: The Electron Transport Chain produces the most ATP (about 32-34
molecules) through oxidative phosphorylation, compared to only 2 ATP from glycolysis
and 2 from the Krebs cycle.
Q7: A plant cell uses energy from the sun to convert carbon dioxide and water into
glucose. What is the name of this process?
A. Cellular respiration
B. Photosynthesis [CORRECT]
C. Fermentation
2026/2027 | Actual Questions and Answers
| Complete Test | Pass Guaranteed - A+
Graded
Cell Biology & Cellular Processes
Q1: You are viewing a cell under a microscope and observe that it lacks a nucleus and
membrane-bound organelles. Based on this observation, how would you classify this
cell?
A. Eukaryotic cell
B. Prokaryotic cell [CORRECT]
C. Animal cell
D. Plant cell
Correct Answer: B
Rationale: Prokaryotic cells are characterized by the absence of a true nucleus and
membrane-bound organelles, distinguishing them from eukaryotic cells which possess
both.
Q2: If a cell requires a significant amount of energy to perform active transport, which
organelle would be most abundant in that cell?
A. Nucleus
B. Ribosome
C. Mitochondria [CORRECT]
D. Golgi apparatus
Correct Answer: C
Rationale: Mitochondria are the sites of aerobic cellular respiration and generate ATP
(energy), so cells with high energy demands (like those using active transport) have
many mitochondria.
Q3: Which component of the cell membrane is primarily responsible for controlling what
enters and exits the cell?
A. Phospholipid bilayer
B. Cholesterol
C. Proteins [CORRECT]
, D. Carbohydrates
Correct Answer: C
Rationale: While the phospholipid bilayer provides the basic structure, membrane
proteins (channels, pumps, and carriers) are specifically responsible for regulating the
transport of substances across the membrane.
Q4: A red blood cell is placed in a beaker of pure water. What will happen to the cell,
and what is this process called?
A. The cell will shrink (crenate) due to osmosis.
B. The cell will swell and possibly burst (lyse) due to osmosis. [CORRECT]
C. The cell will remain the same size due to diffusion.
D. The cell will shrink due to active transport.
Correct Answer: B
Rationale: Pure water is a hypotonic solution relative to the cell's cytoplasm, causing
water to move into the cell via osmosis, leading to swelling and potential bursting (lysis).
Q5: During the process of cellular respiration, which molecule is broken down to release
energy in the form of ATP?
A. Carbon dioxide
B. Water
C. Glucose [CORRECT]
D. Oxygen
Correct Answer: C
Rationale: Glucose is the primary fuel molecule broken down during glycolysis, the
Krebs cycle, and the electron transport chain to produce ATP.
Q6: In which phase of cellular respiration is the majority of ATP produced?
A. Glycolysis
B. Krebs Cycle (Citric Acid Cycle)
C. Electron Transport Chain [CORRECT]
D. Fermentation
Correct Answer: C
Rationale: The Electron Transport Chain produces the most ATP (about 32-34
molecules) through oxidative phosphorylation, compared to only 2 ATP from glycolysis
and 2 from the Krebs cycle.
Q7: A plant cell uses energy from the sun to convert carbon dioxide and water into
glucose. What is the name of this process?
A. Cellular respiration
B. Photosynthesis [CORRECT]
C. Fermentation
