BIOD 152 AP2 LAB 3 ACTUAL EXAM 2026/2027 | Portage Learning | 25
Questions with Rationales | Complete Answer Key | Updated Lab Edition |
Pass Guaranteed - A+ Graded
Q1 (Diagram Labeling): Image description: Sagittal section of the human eye showing
external and internal structures with numbered pointers (1-10).
Identify structures 1-10:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Correct Answer:
1. Cornea [CORRECT]
2. Anterior chamber [CORRECT]
3. Iris [CORRECT]
4. Pupil [CORRECT]
5. Lens [CORRECT]
6. Ciliary body [CORRECT]
7. Suspensory ligaments (zonular fibers) [CORRECT]
8. Vitreous humor (vitreous body) [CORRECT]
9. Retina [CORRECT]
10. Optic disc (blind spot) [CORRECT]
Rationale: This sagittal view demonstrates the three tunics of the eye and optical
components:
, ● Cornea (1): Transparent anterior portion of fibrous tunic; provides ~65% of eye's
refractive power; avascular (nutrients from aqueous humor and tear film)
● Anterior chamber (2): Space between cornea and iris; filled with aqueous humor;
drainage angle at periphery leads to canal of Schlemm
● Iris (3): Colored muscular diaphragm of vascular tunic; contains sphincter
pupillae (parasympathetic, constricts) and dilator pupillae (sympathetic, dilates)
● Pupil (4): Central aperture regulating light entry; constricts in bright
light/accommodation (miosis), dilates in dark (mydriasis)
● Lens (5): Biconvex, avascular, flexible structure; changes shape for
accommodation; held by suspensory ligaments
● Ciliary body (6): Thickened region of vascular tunic; contains ciliary muscle
(accommodation) and ciliary processes (aqueous humor production)
● Suspensory ligaments (7): Zonular fibers attaching ciliary body to lens capsule;
tension changes lens shape
● Vitreous humor (8): Gel-like substance in posterior cavity (between lens and
retina); maintains eye shape; formed during embryonic development, not
regenerated
● Retina (9): Nervous tunic containing photoreceptors; 10-layered structure with
rods/cones, bipolar cells, ganglion cells
● Optic disc (10): Where optic nerve exits; no photoreceptors ("blind spot"); central
retinal artery/vein enter here
Q2 (Multiple Choice): Which layer of the eye contains the melanocytes that provide
pigment and absorb scattered light to prevent visual confusion?
A. Sclera
B. Choroid [CORRECT]
C. Cornea
D. Conjunctiva
Correct Answer: B
Rationale: The choroid is the vascular tunic layer between the sclera and retina,
containing dense melanocytes that absorb scattered light (preventing reflection/internal
, glare) and providing blood supply to outer retinal layers. It is highly pigmented (appears
dark brown/black in dissection).
● A (Sclera) is the opaque white outer layer (fibrous tunic) providing structural
support; avascular except at surface.
● C (Cornea) is transparent and avascular; no pigment (would block light
transmission).
● D (Conjunctiva) is a mucous membrane covering sclera and inner eyelids;
contains blood vessels but not melanocytes for light absorption.
Q3 (Diagram Labeling): Image description: Detailed anatomy of the ear showing
external, middle, and inner ear structures with lettered pointers (A-L).
Identify structures A-L:
A. _____________
B. _____________
C. _____________
D. _____________
E. _____________
F. _____________
G. _____________
H. _____________
I. _____________
J. _____________
K. _____________
L. _____________
Correct Answer:
A. Pinna (auricle) [CORRECT]
B. External auditory canal (external acoustic meatus) [CORRECT]
C. Tympanic membrane (eardrum) [CORRECT]
D. Malleus [CORRECT]
E. Incus [CORRECT]
F. Stapes [CORRECT]
G. Oval window [CORRECT]
H. Cochlea [CORRECT]
I. Semicircular canals [CORRECT]
Questions with Rationales | Complete Answer Key | Updated Lab Edition |
Pass Guaranteed - A+ Graded
Q1 (Diagram Labeling): Image description: Sagittal section of the human eye showing
external and internal structures with numbered pointers (1-10).
Identify structures 1-10:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Correct Answer:
1. Cornea [CORRECT]
2. Anterior chamber [CORRECT]
3. Iris [CORRECT]
4. Pupil [CORRECT]
5. Lens [CORRECT]
6. Ciliary body [CORRECT]
7. Suspensory ligaments (zonular fibers) [CORRECT]
8. Vitreous humor (vitreous body) [CORRECT]
9. Retina [CORRECT]
10. Optic disc (blind spot) [CORRECT]
Rationale: This sagittal view demonstrates the three tunics of the eye and optical
components:
, ● Cornea (1): Transparent anterior portion of fibrous tunic; provides ~65% of eye's
refractive power; avascular (nutrients from aqueous humor and tear film)
● Anterior chamber (2): Space between cornea and iris; filled with aqueous humor;
drainage angle at periphery leads to canal of Schlemm
● Iris (3): Colored muscular diaphragm of vascular tunic; contains sphincter
pupillae (parasympathetic, constricts) and dilator pupillae (sympathetic, dilates)
● Pupil (4): Central aperture regulating light entry; constricts in bright
light/accommodation (miosis), dilates in dark (mydriasis)
● Lens (5): Biconvex, avascular, flexible structure; changes shape for
accommodation; held by suspensory ligaments
● Ciliary body (6): Thickened region of vascular tunic; contains ciliary muscle
(accommodation) and ciliary processes (aqueous humor production)
● Suspensory ligaments (7): Zonular fibers attaching ciliary body to lens capsule;
tension changes lens shape
● Vitreous humor (8): Gel-like substance in posterior cavity (between lens and
retina); maintains eye shape; formed during embryonic development, not
regenerated
● Retina (9): Nervous tunic containing photoreceptors; 10-layered structure with
rods/cones, bipolar cells, ganglion cells
● Optic disc (10): Where optic nerve exits; no photoreceptors ("blind spot"); central
retinal artery/vein enter here
Q2 (Multiple Choice): Which layer of the eye contains the melanocytes that provide
pigment and absorb scattered light to prevent visual confusion?
A. Sclera
B. Choroid [CORRECT]
C. Cornea
D. Conjunctiva
Correct Answer: B
Rationale: The choroid is the vascular tunic layer between the sclera and retina,
containing dense melanocytes that absorb scattered light (preventing reflection/internal
, glare) and providing blood supply to outer retinal layers. It is highly pigmented (appears
dark brown/black in dissection).
● A (Sclera) is the opaque white outer layer (fibrous tunic) providing structural
support; avascular except at surface.
● C (Cornea) is transparent and avascular; no pigment (would block light
transmission).
● D (Conjunctiva) is a mucous membrane covering sclera and inner eyelids;
contains blood vessels but not melanocytes for light absorption.
Q3 (Diagram Labeling): Image description: Detailed anatomy of the ear showing
external, middle, and inner ear structures with lettered pointers (A-L).
Identify structures A-L:
A. _____________
B. _____________
C. _____________
D. _____________
E. _____________
F. _____________
G. _____________
H. _____________
I. _____________
J. _____________
K. _____________
L. _____________
Correct Answer:
A. Pinna (auricle) [CORRECT]
B. External auditory canal (external acoustic meatus) [CORRECT]
C. Tympanic membrane (eardrum) [CORRECT]
D. Malleus [CORRECT]
E. Incus [CORRECT]
F. Stapes [CORRECT]
G. Oval window [CORRECT]
H. Cochlea [CORRECT]
I. Semicircular canals [CORRECT]
