OPTOMETRY ADMISSION TEST (OAT) EXAM
PHYSICS, CHEMISTRY, BIOLOGY, READING
COMPREHENSION & QUANTITATIVE REASONING
QUESTIONS AND CORRECT DETAILED ANSWERS
WITH RATIONALES || 100% GUARANTEED PASS!!
<LATEST VERSION>
Biology & General Chemistry
1.
Which cellular structure is primarily responsible for modifying, sorting, and
packaging proteins for secretion?
A. Ribosome
B. Rough endoplasmic reticulum
C. Golgi apparatus
D. Lysosome
Correct Answer: C
Rationale:
Proteins synthesized on ribosomes attached to the rough ER are transported to the
Golgi apparatus, where they are modified (e.g., glycosylation), sorted, and
packaged into vesicles for secretion or delivery to other organelles.
,2.
A decrease in pH inside a cell would most directly affect which type of chemical
bond?
A. Ionic bonds
B. Hydrogen bonds
C. Covalent bonds
D. Peptide bonds
Correct Answer: B
Rationale:
Changes in pH alter hydrogen bonding by affecting proton availability, which can
disrupt protein secondary and tertiary structure. Covalent and peptide bonds are
much more stable under physiological pH changes.
3.
Which phase of mitosis is characterized by chromosomes aligning at the cell’s
equatorial plane?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
Correct Answer: B
Rationale:
During metaphase, chromosomes line up along the metaphase plate, allowing
proper attachment of spindle fibers prior to separation.
,4.
Which molecule acts as the primary energy currency of the cell?
A. ADP
B. AMP
C. ATP
D. NADH
Correct Answer: C
Rationale:
ATP stores energy in its high-energy phosphate bonds and releases energy when
hydrolyzed, driving most cellular processes.
5.
In humans, which organ system is primarily responsible for maintaining acid–base
balance?
A. Digestive system
B. Respiratory system
C. Nervous system
D. Integumentary system
Correct Answer: B
Rationale:
The respiratory system regulates blood pH by controlling carbon dioxide levels,
which directly influence carbonic acid concentration in blood.
6.
Which macromolecule is composed of monomers linked by ester bonds?
A. Proteins
B. Carbohydrates
C. Nucleic acids
D. Lipids
, Correct Answer: D
Rationale:
Lipids such as triglycerides consist of fatty acids linked to glycerol by ester bonds.
7.
Which enzyme is responsible for breaking down starch into maltose during
digestion?
A. Pepsin
B. Amylase
C. Lipase
D. Trypsin
Correct Answer: B
Rationale:
Amylase, secreted in saliva and pancreatic juice, hydrolyzes starch into smaller
sugars like maltose.
8.
Which component of blood is primarily responsible for oxygen transport?
A. Plasma
B. Platelets
C. Leukocytes
D. Erythrocytes
Correct Answer: D
Rationale:
Erythrocytes contain hemoglobin, which binds and transports oxygen throughout
the body.
PHYSICS, CHEMISTRY, BIOLOGY, READING
COMPREHENSION & QUANTITATIVE REASONING
QUESTIONS AND CORRECT DETAILED ANSWERS
WITH RATIONALES || 100% GUARANTEED PASS!!
<LATEST VERSION>
Biology & General Chemistry
1.
Which cellular structure is primarily responsible for modifying, sorting, and
packaging proteins for secretion?
A. Ribosome
B. Rough endoplasmic reticulum
C. Golgi apparatus
D. Lysosome
Correct Answer: C
Rationale:
Proteins synthesized on ribosomes attached to the rough ER are transported to the
Golgi apparatus, where they are modified (e.g., glycosylation), sorted, and
packaged into vesicles for secretion or delivery to other organelles.
,2.
A decrease in pH inside a cell would most directly affect which type of chemical
bond?
A. Ionic bonds
B. Hydrogen bonds
C. Covalent bonds
D. Peptide bonds
Correct Answer: B
Rationale:
Changes in pH alter hydrogen bonding by affecting proton availability, which can
disrupt protein secondary and tertiary structure. Covalent and peptide bonds are
much more stable under physiological pH changes.
3.
Which phase of mitosis is characterized by chromosomes aligning at the cell’s
equatorial plane?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
Correct Answer: B
Rationale:
During metaphase, chromosomes line up along the metaphase plate, allowing
proper attachment of spindle fibers prior to separation.
,4.
Which molecule acts as the primary energy currency of the cell?
A. ADP
B. AMP
C. ATP
D. NADH
Correct Answer: C
Rationale:
ATP stores energy in its high-energy phosphate bonds and releases energy when
hydrolyzed, driving most cellular processes.
5.
In humans, which organ system is primarily responsible for maintaining acid–base
balance?
A. Digestive system
B. Respiratory system
C. Nervous system
D. Integumentary system
Correct Answer: B
Rationale:
The respiratory system regulates blood pH by controlling carbon dioxide levels,
which directly influence carbonic acid concentration in blood.
6.
Which macromolecule is composed of monomers linked by ester bonds?
A. Proteins
B. Carbohydrates
C. Nucleic acids
D. Lipids
, Correct Answer: D
Rationale:
Lipids such as triglycerides consist of fatty acids linked to glycerol by ester bonds.
7.
Which enzyme is responsible for breaking down starch into maltose during
digestion?
A. Pepsin
B. Amylase
C. Lipase
D. Trypsin
Correct Answer: B
Rationale:
Amylase, secreted in saliva and pancreatic juice, hydrolyzes starch into smaller
sugars like maltose.
8.
Which component of blood is primarily responsible for oxygen transport?
A. Plasma
B. Platelets
C. Leukocytes
D. Erythrocytes
Correct Answer: D
Rationale:
Erythrocytes contain hemoglobin, which binds and transports oxygen throughout
the body.
