Optometry Admission Test (OAT)
National Standardized
Examination: Comprehensive
Practice Question Bank v2.0
updated 2025/2026 graded A+
well written
EXAM TITLE
Optometry Admission Test (OAT) Advanced Mastery Examination v2.0: A
Comprehensive 150-Question Practice Bank Covering Survey of Natural Sciences,
Physics, Reading Comprehension, and Quantitative Reasoning for Pre-Optometry
Candidates Pursuing Doctoral-Level Optometric Education
SECTION I: BIOLOGY (Questions 1–40)
Cellular and Molecular Biology
1. Which of the following statements correctly describes the fluid mosaic model of
the plasma membrane?
,A) The membrane is a rigid, static structure with proteins embedded in a phospholipid
bilayer
B) The membrane consists of a phospholipid bilayer with integral proteins that can
move laterally within the layer
C) The membrane is composed of a single layer of phospholipids with proteins attached
to the surface
D) The membrane consists of proteins embedded in a carbohydrate matrix
E) The membrane is composed entirely of cholesterol and glycolipids
Correct Answer: B
Rationale: The fluid mosaic model describes the plasma membrane as a fluid
phospholipid bilayer with embedded proteins that can move laterally within the
membrane. This fluidity allows for membrane dynamics and function.
2. During cellular respiration, the majority of ATP is produced during which stage?
A) Glycolysis
B) Pyruvate oxidation
C) Citric acid cycle
D) Oxidative phosphorylation
E) Fermentation
Correct Answer: D
Rationale: Oxidative phosphorylation, occurring in the inner mitochondrial membrane,
produces approximately 28-34 ATP molecules per glucose molecule, far more than
glycolysis (2 ATP) or the citric acid cycle (2 ATP).
,3. Which of the following enzymes is responsible for unwinding the DNA double
helix during replication?
A) DNA polymerase
B) Primase
C) Helicase
D) Ligase
E) Topoisomerase
Correct Answer: C
Rationale: Helicase unwinds the DNA double helix by breaking hydrogen bonds
between complementary base pairs. DNA polymerase synthesizes new strands, primase
synthesizes RNA primers, ligase joins Okazaki fragments, and topoisomerase relieves
supercoiling.
4. A cell has a mutation that prevents the formation of the mitotic spindle. Which
phase of the cell cycle would be directly affected?
A) G₁ phase
B) S phase
C) G₂ phase
D) M phase
E) G₀ phase
Correct Answer: D
Rationale: The mitotic spindle is essential for chromosome segregation during M phase
(mitosis). Without proper spindle formation, chromosomes cannot align at the
metaphase plate or separate during anaphase.
, 5. Which of the following statements about the endomembrane system is correct?
A) The rough ER synthesizes lipids and detoxifies drugs
B) The smooth ER is studded with ribosomes and synthesizes proteins
C) The Golgi apparatus modifies, sorts, and packages proteins received from the ER
D) Lysosomes are formed directly from the rough ER
E) Peroxisomes are part of the endomembrane system
Correct Answer: C
Rationale: The Golgi apparatus receives proteins from the rough ER, modifies them
(e.g., glycosylation), and sorts/packages them for transport to their destinations. The
rough ER is studded with ribosomes (protein synthesis), while the smooth ER synthesizes
lipids.
6. The chemiosmotic theory explains ATP production during oxidative
phosphorylation through:
A) Substrate-level phosphorylation
B) A proton gradient across the inner mitochondrial membrane
C) Direct transfer of phosphate from ADP
D) Reduction of NAD⁺ to NADH
E) Oxidation of FADH₂
Correct Answer: B
Rationale: Chemiosmosis involves the creation of a proton (H⁺) gradient across the
inner mitochondrial membrane by the electron transport chain. ATP synthase uses the
flow of protons back across the membrane to phosphorylate ADP to ATP.
National Standardized
Examination: Comprehensive
Practice Question Bank v2.0
updated 2025/2026 graded A+
well written
EXAM TITLE
Optometry Admission Test (OAT) Advanced Mastery Examination v2.0: A
Comprehensive 150-Question Practice Bank Covering Survey of Natural Sciences,
Physics, Reading Comprehension, and Quantitative Reasoning for Pre-Optometry
Candidates Pursuing Doctoral-Level Optometric Education
SECTION I: BIOLOGY (Questions 1–40)
Cellular and Molecular Biology
1. Which of the following statements correctly describes the fluid mosaic model of
the plasma membrane?
,A) The membrane is a rigid, static structure with proteins embedded in a phospholipid
bilayer
B) The membrane consists of a phospholipid bilayer with integral proteins that can
move laterally within the layer
C) The membrane is composed of a single layer of phospholipids with proteins attached
to the surface
D) The membrane consists of proteins embedded in a carbohydrate matrix
E) The membrane is composed entirely of cholesterol and glycolipids
Correct Answer: B
Rationale: The fluid mosaic model describes the plasma membrane as a fluid
phospholipid bilayer with embedded proteins that can move laterally within the
membrane. This fluidity allows for membrane dynamics and function.
2. During cellular respiration, the majority of ATP is produced during which stage?
A) Glycolysis
B) Pyruvate oxidation
C) Citric acid cycle
D) Oxidative phosphorylation
E) Fermentation
Correct Answer: D
Rationale: Oxidative phosphorylation, occurring in the inner mitochondrial membrane,
produces approximately 28-34 ATP molecules per glucose molecule, far more than
glycolysis (2 ATP) or the citric acid cycle (2 ATP).
,3. Which of the following enzymes is responsible for unwinding the DNA double
helix during replication?
A) DNA polymerase
B) Primase
C) Helicase
D) Ligase
E) Topoisomerase
Correct Answer: C
Rationale: Helicase unwinds the DNA double helix by breaking hydrogen bonds
between complementary base pairs. DNA polymerase synthesizes new strands, primase
synthesizes RNA primers, ligase joins Okazaki fragments, and topoisomerase relieves
supercoiling.
4. A cell has a mutation that prevents the formation of the mitotic spindle. Which
phase of the cell cycle would be directly affected?
A) G₁ phase
B) S phase
C) G₂ phase
D) M phase
E) G₀ phase
Correct Answer: D
Rationale: The mitotic spindle is essential for chromosome segregation during M phase
(mitosis). Without proper spindle formation, chromosomes cannot align at the
metaphase plate or separate during anaphase.
, 5. Which of the following statements about the endomembrane system is correct?
A) The rough ER synthesizes lipids and detoxifies drugs
B) The smooth ER is studded with ribosomes and synthesizes proteins
C) The Golgi apparatus modifies, sorts, and packages proteins received from the ER
D) Lysosomes are formed directly from the rough ER
E) Peroxisomes are part of the endomembrane system
Correct Answer: C
Rationale: The Golgi apparatus receives proteins from the rough ER, modifies them
(e.g., glycosylation), and sorts/packages them for transport to their destinations. The
rough ER is studded with ribosomes (protein synthesis), while the smooth ER synthesizes
lipids.
6. The chemiosmotic theory explains ATP production during oxidative
phosphorylation through:
A) Substrate-level phosphorylation
B) A proton gradient across the inner mitochondrial membrane
C) Direct transfer of phosphate from ADP
D) Reduction of NAD⁺ to NADH
E) Oxidation of FADH₂
Correct Answer: B
Rationale: Chemiosmosis involves the creation of a proton (H⁺) gradient across the
inner mitochondrial membrane by the electron transport chain. ATP synthase uses the
flow of protons back across the membrane to phosphorylate ADP to ATP.
