Test: Sensory Reception & Processing (NCERT) - Grade 12 MCQ

Correct Answer Option: C
Mycorrhiza refers to a symbiotic association between fungi and the roots of a plant. In this relationship, the fungus enhances the plant's nutrient and water absorption capabilities, while the plant provides the fungus with carbohydrates produced through photosynthesis.

Option A is correct:
A−(vii), B−(iii), C−(vi), D−(v), E−(i), F−(iv), G−(ii)

Cochlea is the main hearing organ. The transformation of the vibration into nerve impulses for relay to the brain takes place here.

Cristae and maculae, the structures concerned with balance are located in the inner ear.

Internal ear (membranous labyrinth) is surrounded by an almost similar shaped bony labyrinth. The membranous labyrinth is joined to the bony labyrinth at certain points, but its greater part is separated from the bony labyrinth by a narrow perilymphatic space. This space is filled with a watery fluid called perilymph that closely resembles cerebrospinal fluid

Tympanic cavity (part of middle ear) is an air filled cavity that is connected with the nasopharynx through Eustachian tube. It serves to equalise the air pressure in the tympanic cavity with that on the outside

• The retina is the innermost layer that surrounds the eye.
• It contains a yellow-pigmented region near its center at the posterior pole of the eye known as the macula lutea.
• The central pit of the macula lutea is the fovea.

Rhodopsin is a pigment present in the rod cells of the retina. It consists of two components-opsin and retinal (= retinene). Retinal is an aldehyde of vitamin A which absorbs light falling on the rod and changes its form and separates from the opsin component. This initiates the transmission of a nerve impulse to the brain. Rhodopsin is a photosensitive substance and allows vision in dim light (night vision).

Cornea is a transparent layer of tissue continuous with sclerotic that forms the front part of vertebrate eye over the iris and lens. It refracts light waves entering the eye onto lens. Cornea is avascular (i.e., has no blood supply). It is one of the first organs to be successfully transplanted because it lacks blood vessels.

The black pigment, melanin in the eye, which reduces the internal reflection is located in the pigment layer of retina.

• The given diagram is that of the cross section of the eye.
• The indicated structure is present at the anterior pole of the eye, on the outermost layer called sclera.
• It is identified to be the cornea.

Semicircular canal, sacculus and utriculus are receptors of equilibrium or balancing organs of ear.

Ciliary muscles are circular sheet of smooth muscle fibres present within the ciliary body. These muscles alter the shape of the lens during contraction.

Proteins found in eye lens are crystallins which are transaprent proteins.

Cone cells are chiefly concerned with distinction colour and light vision during day time.

The size of pupil is controlled by two types of muscles of iris, circular muscles and radial muscles. Radial muscles contract in dim light and circular muscles contract in bright light.

Cornea is covered externally by a thin transparent membrane called conjunctiva. This membrane helps to protect the eye ball and keeps it moist.

Tectorial membrane is a gelatinous membrane covering the sensory hair cells in the scala media of cochlea.

Retina of our eye is analogous to the light sensitive film of camera.

Blind spot lies close to the yellow spot of the eye and lacks receptor cells (rods and cones) because the optic nerves leave the eye ball from here.

Internal ear consists of two divisions:
(i) bony labyrinth, filled with fluid called perilymph
(ii) membranous labyrinth, filled with fluid called endolymph

Aqueous humour is a watery, alkaline liquid filling the anterior compartment of the eye. It is present between the cornea and the lens. It maintains the shape of the cornea and supplies nutrition to both lens and cornea.

The correct answer is option C. Here's the breakdown:
- Structure c: Found in the small intestine.
- Function: Responsible for absorption of nutrients from digested food.
This structure is likely the villi in the small intestine. Villi are finger-like projections that increase the surface area of the small intestine for better absorption of nutrients through the intestinal walls. They contain blood vessels and lacteals to absorb nutrients into the bloodstream.

The innermost layer of the human eye is retina which is a light sensitive layer. It consists of rods and cones.

As fovea centralis contains a large number of cones only, therefore, it is a point of great visual acuity in retina.