Q.1 Which part of the eye is responsible for refracting the majority of incoming light?
Lens
Cornea
Retina
Iris
Explanation - The cornea provides about two-thirds of the eye's total refractive power, while the lens fine-tunes the focus.
Correct answer is: Cornea
Q.2 Rods in the retina are primarily responsible for:
Color vision
Bright light vision
Night vision
Central vision
Explanation - Rods are highly sensitive to low light and enable vision in dim conditions, but do not detect color.
Correct answer is: Night vision
Q.3 Which structure of the ear converts sound vibrations into electrical signals?
Cochlea
Tympanic membrane
Malleus
Eustachian tube
Explanation - The cochlea contains hair cells that transduce mechanical vibrations into electrical impulses for hearing.
Correct answer is: Cochlea
Q.4 Which cranial nerve carries visual information from the retina to the brain?
Optic nerve (CN II)
Oculomotor nerve (CN III)
Trochlear nerve (CN IV)
Trigeminal nerve (CN V)
Explanation - The optic nerve transmits visual information to the occipital cortex for processing.
Correct answer is: Optic nerve (CN II)
Q.5 The fovea centralis is specialized for:
Peripheral vision
Low-light vision
Sharp central vision
Colorless vision
Explanation - The fovea contains a high density of cones and is the point of maximal visual acuity.
Correct answer is: Sharp central vision
Q.6 Taste buds are located mainly on which papillae?
Filiform
Fungiform
Circumvallate
All of the above except filiform
Explanation - Taste buds are found on fungiform, circumvallate, and foliate papillae, but not on filiform papillae.
Correct answer is: All of the above except filiform
Q.7 Which structure equalizes air pressure across the tympanic membrane?
Semicircular canals
Cochlea
Eustachian tube
Ossicles
Explanation - The Eustachian tube maintains equal air pressure between the middle ear and the atmosphere.
Correct answer is: Eustachian tube
Q.8 Which photoreceptors detect color in daylight?
Rods
Cones
Ganglion cells
Bipolar cells
Explanation - Cones are responsible for high-acuity color vision under bright light conditions.
Correct answer is: Cones
Q.9 The vestibular apparatus in the inner ear helps in:
Hearing
Balance
Smell
Taste
Explanation - The vestibular system detects head movements and spatial orientation to maintain equilibrium.
Correct answer is: Balance
Q.10 Which cranial nerve carries information about smell?
CN I
CN II
CN VII
CN IX
Explanation - The olfactory nerve (CN I) carries sensory input related to smell to the brain.
Correct answer is: CN I
Q.11 Which part of the retina has no photoreceptors and forms the blind spot?
Fovea
Macula
Optic disc
Periphery
Explanation - The optic disc is where the optic nerve exits the eye, lacking rods and cones, causing a blind spot.
Correct answer is: Optic disc
Q.12 Which taste sensation is triggered by glutamate?
Sweet
Umami
Bitter
Salty
Explanation - Umami taste is stimulated by amino acids like glutamate and provides a savory flavor.
Correct answer is: Umami
Q.13 Which fluid fills the anterior chamber of the eye?
Vitreous humor
Aqueous humor
Endolymph
Perilymph
Explanation - The aqueous humor nourishes the cornea and lens and maintains intraocular pressure.
Correct answer is: Aqueous humor
Q.14 Which structure of the inner ear detects rotational acceleration?
Utricle
Saccule
Semicircular canals
Cochlea
Explanation - The semicircular canals sense angular acceleration of the head.
Correct answer is: Semicircular canals
Q.15 Which part of the ear amplifies sound vibrations?
Pinna
Ossicles
Cochlea
Semicircular canals
Explanation - The ossicles (malleus, incus, stapes) amplify and transmit sound to the inner ear.
Correct answer is: Ossicles
Q.16 Which ion is crucial for depolarization in auditory hair cells?
Sodium
Potassium
Calcium
Chloride
Explanation - Endolymph in the cochlea is rich in potassium, which depolarizes hair cells upon stimulation.
Correct answer is: Potassium
Q.17 Color blindness is usually due to defects in:
Rods
Cones
Lens
Cornea
Explanation - Deficiency in specific cone pigments (red, green, or blue) causes color blindness.
Correct answer is: Cones
Q.18 Which cranial nerve transmits taste from the anterior two-thirds of the tongue?
Glossopharyngeal (CN IX)
Vagus (CN X)
Facial (CN VII)
Trigeminal (CN V)
Explanation - The chorda tympani branch of CN VII carries taste from the anterior 2/3 of the tongue.
Correct answer is: Facial (CN VII)
Q.19 Which photopigment is present in rods?
Iodopsin
Rhodopsin
Opsin
Melanopsin
Explanation - Rhodopsin is the light-sensitive pigment in rods essential for scotopic (night) vision.
Correct answer is: Rhodopsin
Q.20 Which sense does the organ of Corti mediate?
Smell
Taste
Hearing
Balance
Explanation - The organ of Corti in the cochlea contains hair cells that transduce sound vibrations into neural signals.
Correct answer is: Hearing
Q.21 Which part of the eye regulates the amount of light entering?
Lens
Cornea
Iris
Retina
Explanation - The iris adjusts the pupil size, controlling the amount of light entering the eye.
Correct answer is: Iris
Q.22 Which cranial nerve controls eye movement and pupil constriction?
CN II
CN III
CN IV
CN VI
Explanation - The oculomotor nerve (CN III) controls most extraocular muscles and pupil constriction.
Correct answer is: CN III
Q.23 The macula of the utricle detects:
Linear acceleration
Angular acceleration
Sound waves
Light intensity
Explanation - The utricle and saccule sense linear acceleration and head tilt.
Correct answer is: Linear acceleration
Q.24 Which papillae are most numerous on the tongue?
Filiform
Fungiform
Circumvallate
Foliate
Explanation - Filiform papillae are numerous and provide texture, but they lack taste buds.
Correct answer is: Filiform
Q.25 Which part of the retina contains the highest density of cones?
Optic disc
Fovea centralis
Macula periphery
Retinal periphery
Explanation - The fovea centralis provides sharp, detailed, and color vision due to its high cone density.
Correct answer is: Fovea centralis