,BIOL 251 Module 8 | Human Anatomy & Physiology I w/Lab Exam
Q&A | Portage Learning
1. Which of the following is NOT considered a special sense?
A) Smell
B) Touch
C) Taste
D) Hearing
Correct Answer: Touch
Rationale: The special senses include smell (olfaction), taste (gustation), vision, hearing
(audition), and equilibrium (balance). Touch is classified as a general (somatesthetic) sense
because its receptors are distributed throughout the body, not confined to specialized
organs in the head.
2. Which part of the eye controls the amount of light entering the eye by adjusting the
size of the pupil?
A) Retina
B) Cornea
C) Iris
D) Optic nerve
Correct Answer: Iris
Rationale: The iris is the colored part of the eye that contains smooth muscle fibers. It
adjusts the size of the pupil to regulate the amount of light that enters the eye,
functioning much like the aperture of a camera.
,3. Which of the following photoreceptors is primarily responsible for vision in dim light
conditions?
A) Cones
B) Rods
C) Bipolar cells
D) Ganglion cells
Correct Answer: Rods
Rationale: Rods are photoreceptor cells in the retina that are highly sensitive to light,
making them essential for night vision and vision in low-light conditions. They do not
detect color, which is the function of cones.
4. The photoreceptors of the eye are located in which structure?
A) Cornea
B) Lens
C) Retina
D) Vitreous humor
Correct Answer: Retina
Rationale: The retina is the innermost layer of the eye and contains the photoreceptor
cells (rods and cones). These cells convert light energy into neural signals that are sent to
the brain via the optic nerve.
5. Which structure of the eye is responsible for focusing light onto the retina?
A) Cornea
, B) Iris
C) Pupil
D) Lens
Correct Answer: Lens
Rationale: The lens is a transparent, biconvex structure that bends (refracts) light rays to
focus them precisely onto the retina. While the cornea also refracts light, the lens provides
the fine adjustment needed for focusing on objects at varying distances.
6. The fibrous layer of the eye includes which two structures?
A) Retina and choroid
B) Sclera and cornea
C) Iris and ciliary body
D) Lens and vitreous body
Correct Answer: Sclera and cornea
Rationale: The fibrous layer is the outermost layer of the eye and consists of the sclera (the
"white" of the eye) and the cornea (the transparent anterior portion). The vascular layer
includes the choroid, iris, and ciliary body. The retina is the innermost nervous layer.
7. The structure responsible for focusing light on the retina by changing its shape is the:
A) Cornea
B) Iris
C) Lens
D) Pupil
Q&A | Portage Learning
1. Which of the following is NOT considered a special sense?
A) Smell
B) Touch
C) Taste
D) Hearing
Correct Answer: Touch
Rationale: The special senses include smell (olfaction), taste (gustation), vision, hearing
(audition), and equilibrium (balance). Touch is classified as a general (somatesthetic) sense
because its receptors are distributed throughout the body, not confined to specialized
organs in the head.
2. Which part of the eye controls the amount of light entering the eye by adjusting the
size of the pupil?
A) Retina
B) Cornea
C) Iris
D) Optic nerve
Correct Answer: Iris
Rationale: The iris is the colored part of the eye that contains smooth muscle fibers. It
adjusts the size of the pupil to regulate the amount of light that enters the eye,
functioning much like the aperture of a camera.
,3. Which of the following photoreceptors is primarily responsible for vision in dim light
conditions?
A) Cones
B) Rods
C) Bipolar cells
D) Ganglion cells
Correct Answer: Rods
Rationale: Rods are photoreceptor cells in the retina that are highly sensitive to light,
making them essential for night vision and vision in low-light conditions. They do not
detect color, which is the function of cones.
4. The photoreceptors of the eye are located in which structure?
A) Cornea
B) Lens
C) Retina
D) Vitreous humor
Correct Answer: Retina
Rationale: The retina is the innermost layer of the eye and contains the photoreceptor
cells (rods and cones). These cells convert light energy into neural signals that are sent to
the brain via the optic nerve.
5. Which structure of the eye is responsible for focusing light onto the retina?
A) Cornea
, B) Iris
C) Pupil
D) Lens
Correct Answer: Lens
Rationale: The lens is a transparent, biconvex structure that bends (refracts) light rays to
focus them precisely onto the retina. While the cornea also refracts light, the lens provides
the fine adjustment needed for focusing on objects at varying distances.
6. The fibrous layer of the eye includes which two structures?
A) Retina and choroid
B) Sclera and cornea
C) Iris and ciliary body
D) Lens and vitreous body
Correct Answer: Sclera and cornea
Rationale: The fibrous layer is the outermost layer of the eye and consists of the sclera (the
"white" of the eye) and the cornea (the transparent anterior portion). The vascular layer
includes the choroid, iris, and ciliary body. The retina is the innermost nervous layer.
7. The structure responsible for focusing light on the retina by changing its shape is the:
A) Cornea
B) Iris
C) Lens
D) Pupil
