Question

Visual purple is found in
A.Cornea
B.Cones
C.Rods
D.Retina

Answer 1

Rhodopsin, often termed visual purple, is a pigment-containing protein that converts light into an electrical stimulus. Rhodopsin is present in a variety of species, ranging from vertebrates to microbes. In several seeing animals, including humans, sight in faint light is necessary.

Complete answer: Rhodopsin, classified as chromoprotein. This is comprised of opsin (colorless protein) and 11-cis-retinal, a pigmented protein extracted from vitamin A. Whenever the eye is exposed to light, the 11-cis-retinal part of rhodopsin is translated to any and all-trans-retinal, ending in a huge shift in the structure of the molecule of rhodopsin. The structure shift activates a phototransduction pathway inside the rod, which turns the light into electrical signals which will then be sent through the optic nerve to the visual cortex of the brain. The switch in configuration even triggers opsin to disassociate from retinal, leading to bleaching. Bleaching restricts the extent to which rods are excited, reduces the sensitivity to strong light, and induces cone cells (another type of photoreceptor in the retina) to instigate sight in bright circumstances.
So, the correct answer is C.

Additional information:
Rhodopsin protein produced by the Rhodopsin gene is called RHO. Human mutations in RHO are linked with retinitis pigmentosa and inherited genetic congenital vision loss that is hereditary vision loss. In both cases, the retina will be unable to adjust to the dark, resulting in a significantly lowered ability to see a faint light. Whereas cornea is the outer layer of the eyes. The cornea helps preserve the integrity of the eye against germs, dust. The cornea always operates as a shield, shutting out the most harmful ultraviolet (UV) rays in the sunshine, as well as the cornea behaves as an eye lens. It functions like a door that adjusts and focuses the light on the eye. Whenever the light hits the cornea, the light source bends-or refracts-to the lens. In fact, the retina is an extension of the brain, built embryonically from neural cells, and linked to the brain by the optic nerve. As the light hits the eye, it travels through the cornea and lens and is refracted, projecting the vision on the retina.

Note: Rod cells sense the degree of lightness that influences the eye and their sensitivity depends on the amount of Rhodopsin existing in the cells. However, Rhodopsin is damaged by bleaching when exposed to light and thus the rod cells function only in low light because at high illumination the reduced level of this photosensitive pigment contributes to very low sensitivity.