Biol251 / Biol 251 Module & Lab 8:<Anatomy And Physiology I>
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1. A student looks from a distant whiteboard to a near textbook. Which structure changes shape
to focus light onto the retina?
a) Cornea
b) Lens
c) Iris
d) Vitreous humor
➢ CORRECT ANSWER b) Lens
➢ Rationale: The lens accommodates by changing curvature (becoming more convex for
near objects and flatter for distant objects).
2. Which photoreceptor type is responsible for detecting fine detail and color in bright light?
a) Rods
b) Cones
c) Ganglion cells
d) Bipolar cells
➢ CORRECT ANSWER b) Cones
➢ Rationale: Cones provide high-acuity color vision and function best under photopic
(bright light) conditions.
3. A patient reports difficulty seeing in dim light but normal vision during the day. Which
photoreceptor type is most likely dysfunctional?
a) Cones only
b) Rods only
c) Bipolar cells
d) Ganglion cells
➢ CORRECT ANSWER b) Rods only
, ➢ Rationale: Rods are responsible for scotopic (low-light) vision; their dysfunction causes
night blindness (nyctalopia).
4. Which structure controls the amount of light entering the eye by adjusting pupil size?
a) Cornea
b) Lens
c) Iris
d) Retina
➢ CORRECT ANSWER c) Iris
➢ Rationale: The iris contains smooth muscle (sphincter pupillae and dilator pupillae) that
regulates pupil diameter and light entry.
5. Where are the photoreceptors (rods and cones) located within the eye?
a) Cornea
b) Lens
c) Retina
d) Choroid
➢ CORRECT ANSWER c) Retina
➢ Rationale: The retina is the neurosensory layer containing photoreceptors that transduce
light into electrical signals.
6. Which region of the retina contains the highest concentration of cones and is responsible for
sharpest central vision?
a) Optic disc
b) Macula lutea
c) Fovea centralis
d) Peripheral retina
➢ CORRECT ANSWER c) Fovea centralis
➢ Rationale: The fovea centralis has only cones (no rods) and provides maximal visual
acuity due to 1:1 photoreceptor to bipolar cell ratio.
,7. A patient cannot read letters on an eye chart due to blurry distance vision but can read a book
clearly. This condition is:
a) Hyperopia
b) Myopia
c) Presbyopia
d) Astigmatism
➢ CORRECT ANSWER b) Myopia
➢ Rationale: Myopia (nearsightedness) occurs when the eyeball is too long or cornea too
curved, causing light to focus in front of the retina.
8. Which cranial nerve carries visual information from the retina to the brain?
a) CN I (Olfactory)
b) CN II (Optic)
c) CN III (Oculomotor)
d) CN IV (Trochlear)
➢ CORRECT ANSWER b) CN II (Optic)
➢ Rationale: The optic nerve (CN II) is a sensory nerve transmitting visual signals from
retinal ganglion cells to the occipital cortex.
9. The blind spot in the visual field corresponds to which structure?
a) Fovea centralis
b) Macula lutea
c) Optic disc
d) Ciliary body
➢ CORRECT ANSWER c) Optic disc
➢ Rationale: The optic disc lacks photoreceptors because it is where ganglion cell axons
exit the eye, forming the optic nerve.
10. Which sequence correctly describes the path of light through the eye?
a) Cornea → lens → pupil → retina
b) Pupil → cornea → lens → retina
, c) Cornea → pupil → lens → retina
d) Lens → pupil → cornea → retina
➢ CORRECT ANSWER c) Cornea → pupil → lens → retina
➢ Rationale: Light first refracts through cornea, passes through pupil, then lens focuses
image onto retina.
11. During a routine eye exam, the practitioner instills eye drops that cause pupil dilation. These
drops block which receptor type in the iris?
a) Alpha-adrenergic receptors
b) Beta-adrenergic receptors
c) Muscarinic cholinergic receptors
d) Nicotinic cholinergic receptors
➢ CORRECT ANSWER c) Muscarinic cholinergic receptors
➢ Rationale: Mydriatics block muscarinic receptors on the sphincter pupillae, preventing
constriction and allowing dilation.
12. A 55-year-old patient complains of difficulty reading small print, requiring brighter light.
This age-related change is called:
a) Myopia
b) Hyperopia
c) Presbyopia
d) Astigmatism
➢ CORRECT ANSWER c) Presbyopia
➢ Rationale: Presbyopia results from lens stiffening and loss of elasticity with age, reducing
accommodative ability for near vision.
13. Which structure produces aqueous humor?
a) Ciliary body
b) Choroid
c) Sclera
d) Lacrimal gland
Latest Updated Version Structured With Verified Questions That
Are Well Solved Through Accurate Answers &Rationales (2025/2026
Release) -A Masterpiece Already Graded A+!!-
1. A student looks from a distant whiteboard to a near textbook. Which structure changes shape
to focus light onto the retina?
a) Cornea
b) Lens
c) Iris
d) Vitreous humor
➢ CORRECT ANSWER b) Lens
➢ Rationale: The lens accommodates by changing curvature (becoming more convex for
near objects and flatter for distant objects).
2. Which photoreceptor type is responsible for detecting fine detail and color in bright light?
a) Rods
b) Cones
c) Ganglion cells
d) Bipolar cells
➢ CORRECT ANSWER b) Cones
➢ Rationale: Cones provide high-acuity color vision and function best under photopic
(bright light) conditions.
3. A patient reports difficulty seeing in dim light but normal vision during the day. Which
photoreceptor type is most likely dysfunctional?
a) Cones only
b) Rods only
c) Bipolar cells
d) Ganglion cells
➢ CORRECT ANSWER b) Rods only
, ➢ Rationale: Rods are responsible for scotopic (low-light) vision; their dysfunction causes
night blindness (nyctalopia).
4. Which structure controls the amount of light entering the eye by adjusting pupil size?
a) Cornea
b) Lens
c) Iris
d) Retina
➢ CORRECT ANSWER c) Iris
➢ Rationale: The iris contains smooth muscle (sphincter pupillae and dilator pupillae) that
regulates pupil diameter and light entry.
5. Where are the photoreceptors (rods and cones) located within the eye?
a) Cornea
b) Lens
c) Retina
d) Choroid
➢ CORRECT ANSWER c) Retina
➢ Rationale: The retina is the neurosensory layer containing photoreceptors that transduce
light into electrical signals.
6. Which region of the retina contains the highest concentration of cones and is responsible for
sharpest central vision?
a) Optic disc
b) Macula lutea
c) Fovea centralis
d) Peripheral retina
➢ CORRECT ANSWER c) Fovea centralis
➢ Rationale: The fovea centralis has only cones (no rods) and provides maximal visual
acuity due to 1:1 photoreceptor to bipolar cell ratio.
,7. A patient cannot read letters on an eye chart due to blurry distance vision but can read a book
clearly. This condition is:
a) Hyperopia
b) Myopia
c) Presbyopia
d) Astigmatism
➢ CORRECT ANSWER b) Myopia
➢ Rationale: Myopia (nearsightedness) occurs when the eyeball is too long or cornea too
curved, causing light to focus in front of the retina.
8. Which cranial nerve carries visual information from the retina to the brain?
a) CN I (Olfactory)
b) CN II (Optic)
c) CN III (Oculomotor)
d) CN IV (Trochlear)
➢ CORRECT ANSWER b) CN II (Optic)
➢ Rationale: The optic nerve (CN II) is a sensory nerve transmitting visual signals from
retinal ganglion cells to the occipital cortex.
9. The blind spot in the visual field corresponds to which structure?
a) Fovea centralis
b) Macula lutea
c) Optic disc
d) Ciliary body
➢ CORRECT ANSWER c) Optic disc
➢ Rationale: The optic disc lacks photoreceptors because it is where ganglion cell axons
exit the eye, forming the optic nerve.
10. Which sequence correctly describes the path of light through the eye?
a) Cornea → lens → pupil → retina
b) Pupil → cornea → lens → retina
, c) Cornea → pupil → lens → retina
d) Lens → pupil → cornea → retina
➢ CORRECT ANSWER c) Cornea → pupil → lens → retina
➢ Rationale: Light first refracts through cornea, passes through pupil, then lens focuses
image onto retina.
11. During a routine eye exam, the practitioner instills eye drops that cause pupil dilation. These
drops block which receptor type in the iris?
a) Alpha-adrenergic receptors
b) Beta-adrenergic receptors
c) Muscarinic cholinergic receptors
d) Nicotinic cholinergic receptors
➢ CORRECT ANSWER c) Muscarinic cholinergic receptors
➢ Rationale: Mydriatics block muscarinic receptors on the sphincter pupillae, preventing
constriction and allowing dilation.
12. A 55-year-old patient complains of difficulty reading small print, requiring brighter light.
This age-related change is called:
a) Myopia
b) Hyperopia
c) Presbyopia
d) Astigmatism
➢ CORRECT ANSWER c) Presbyopia
➢ Rationale: Presbyopia results from lens stiffening and loss of elasticity with age, reducing
accommodative ability for near vision.
13. Which structure produces aqueous humor?
a) Ciliary body
b) Choroid
c) Sclera
d) Lacrimal gland
