BIOL251 / BIOL 251 Module & Lab 8 Practice Exam: Human
Anatomy & Physiology I with Lab UP-TO-DATE 2026 EXAM
Latest PDF Update)
SECTION A: VISION (THE EYE)
Question 1
Which of the following is the correct order of structures that light passes through as it
enters the eye?
A) Lens → pupil → cornea → retina
B) Cornea → lens → pupil → retina
C) Cornea → pupil → lens → retina
D) Pupil → cornea → lens → retina
Correct Answer: C) Cornea → pupil → lens → retina
Rationale: Light enters the eye sequentially through the cornea (first refractive surface),
passes through the pupil (regulated by the iris), is further focused by the lens, and finally
reaches the retina (neural layer containing photoreceptors) .
Question 2
The gel-like substance that fills the posterior cavity of the eye is the:
A) Aqueous humor
B) Vitreous humor
C) Hyaloid fluid
D) Choroid gel
Correct Answer: B) Vitreous humor
Rationale: The posterior cavity of the eye is filled with vitreous humor, a clear gel that
helps maintain the shape of the eyeball. Aqueous humor fills the anterior chamber of the
eye .
,Question 3
Which of the following structures of the eye is avascular and responsible for the initial
refraction of light?
A) Sclera
B) Choroid
C) Cornea
D) Iris
Correct Answer: C) Cornea
Rationale: The cornea is transparent, avascular, and serves as the primary refractive
surface of the eye, responsible for approximately 80% of light refraction. The sclera is the
tough, white protective outer layer .
Question 4
Which part of the eye controls the amount of light entering the eye?
A) Retina
B) Cornea
C) Iris
D) Optic nerve
Correct Answer: C) Iris
Rationale: The iris regulates the diameter of the pupil, controlling the amount of light that
enters the eye. The retina contains photoreceptors; the cornea refracts light .
Question 5
Which photoreceptor cells are most active in dim lighting and are responsible for night
vision?
A) Cones
B) Rods
,C) Bipolar cells
D) Ganglion cells
Correct Answer: B) Rods
Rationale: Rods are highly sensitive to low light levels and are responsible for scotopic
(dim light) vision. Cones require brighter light and are responsible for color vision and high
acuity .
Question 6
The area of highest visual acuity on the retina is the:
A) Optic disc
B) Macula lutea
C) Fovea centralis
D) Choroid
Correct Answer: C) Fovea centralis
Rationale: The fovea centralis, located within the macula lutea, contains the highest
concentration of cones and is responsible for sharp, detailed central vision .
Question 7
The "blind spot" of the eye, where the optic nerve exits the retina and no
photoreceptors are located, is called the:
A) Macula lutea
B) Fovea centralis
C) Optic disc
D) Ciliary body
Correct Answer: C) Optic disc
Rationale: The optic disc is the point where the optic nerve fibers exit the retina. It lacks
photoreceptors, creating a "blind spot" in the visual field .
, Question 8
A blockage in the canal of Schlemm would most likely lead to which condition?
A) Cataracts
B) Glaucoma
C) Macular degeneration
D) Retinal detachment
Correct Answer: B) Glaucoma
Rationale: The canal of Schlemm drains aqueous humor from the anterior chamber. A
blockage results in increased intraocular pressure (glaucoma), which can damage the optic
nerve .
Question 9
The ciliary muscles contract to:
A) Constrict the pupil
B) Dilate the pupil
C) Flatten the lens for far vision
D) Bulge the lens for near vision
Correct Answer: D) Bulge the lens for near vision
Rationale: During accommodation for near vision, the ciliary muscles contract, reducing
tension on the suspensory ligaments, which allows the lens to bulge (become more
rounded) .
Question 10
Which cranial nerve carries sensory information for vision?
A) CN I (Olfactory)
B) CN II (Optic)
Anatomy & Physiology I with Lab UP-TO-DATE 2026 EXAM
Latest PDF Update)
SECTION A: VISION (THE EYE)
Question 1
Which of the following is the correct order of structures that light passes through as it
enters the eye?
A) Lens → pupil → cornea → retina
B) Cornea → lens → pupil → retina
C) Cornea → pupil → lens → retina
D) Pupil → cornea → lens → retina
Correct Answer: C) Cornea → pupil → lens → retina
Rationale: Light enters the eye sequentially through the cornea (first refractive surface),
passes through the pupil (regulated by the iris), is further focused by the lens, and finally
reaches the retina (neural layer containing photoreceptors) .
Question 2
The gel-like substance that fills the posterior cavity of the eye is the:
A) Aqueous humor
B) Vitreous humor
C) Hyaloid fluid
D) Choroid gel
Correct Answer: B) Vitreous humor
Rationale: The posterior cavity of the eye is filled with vitreous humor, a clear gel that
helps maintain the shape of the eyeball. Aqueous humor fills the anterior chamber of the
eye .
,Question 3
Which of the following structures of the eye is avascular and responsible for the initial
refraction of light?
A) Sclera
B) Choroid
C) Cornea
D) Iris
Correct Answer: C) Cornea
Rationale: The cornea is transparent, avascular, and serves as the primary refractive
surface of the eye, responsible for approximately 80% of light refraction. The sclera is the
tough, white protective outer layer .
Question 4
Which part of the eye controls the amount of light entering the eye?
A) Retina
B) Cornea
C) Iris
D) Optic nerve
Correct Answer: C) Iris
Rationale: The iris regulates the diameter of the pupil, controlling the amount of light that
enters the eye. The retina contains photoreceptors; the cornea refracts light .
Question 5
Which photoreceptor cells are most active in dim lighting and are responsible for night
vision?
A) Cones
B) Rods
,C) Bipolar cells
D) Ganglion cells
Correct Answer: B) Rods
Rationale: Rods are highly sensitive to low light levels and are responsible for scotopic
(dim light) vision. Cones require brighter light and are responsible for color vision and high
acuity .
Question 6
The area of highest visual acuity on the retina is the:
A) Optic disc
B) Macula lutea
C) Fovea centralis
D) Choroid
Correct Answer: C) Fovea centralis
Rationale: The fovea centralis, located within the macula lutea, contains the highest
concentration of cones and is responsible for sharp, detailed central vision .
Question 7
The "blind spot" of the eye, where the optic nerve exits the retina and no
photoreceptors are located, is called the:
A) Macula lutea
B) Fovea centralis
C) Optic disc
D) Ciliary body
Correct Answer: C) Optic disc
Rationale: The optic disc is the point where the optic nerve fibers exit the retina. It lacks
photoreceptors, creating a "blind spot" in the visual field .
, Question 8
A blockage in the canal of Schlemm would most likely lead to which condition?
A) Cataracts
B) Glaucoma
C) Macular degeneration
D) Retinal detachment
Correct Answer: B) Glaucoma
Rationale: The canal of Schlemm drains aqueous humor from the anterior chamber. A
blockage results in increased intraocular pressure (glaucoma), which can damage the optic
nerve .
Question 9
The ciliary muscles contract to:
A) Constrict the pupil
B) Dilate the pupil
C) Flatten the lens for far vision
D) Bulge the lens for near vision
Correct Answer: D) Bulge the lens for near vision
Rationale: During accommodation for near vision, the ciliary muscles contract, reducing
tension on the suspensory ligaments, which allows the lens to bulge (become more
rounded) .
Question 10
Which cranial nerve carries sensory information for vision?
A) CN I (Olfactory)
B) CN II (Optic)
