Question

The photoreceptor cells of the eye are located in the
A. Sclera
B. Iris
C. Retina
D. Optic Nerve

Answer 1

Hint: The photoreceptor cells are the specialized cells of the neuroepithelial cells. These cells are capable of visual phototransduction. They are biologically important as they convert the light into signals which in turn stimulate the biological processes.

Complete answer:
> Option A:
The Sclera is the white portion of the eye that is opaque and fibrous. It forms a protective outer layer for the human eye that comprises some elastic fibers and collagen. Thus, the option [A] is incorrect.

> Option B:
The Iris is the ring shaped flat structural membrane that is located behind the cornea. At the center of the iris, an adjustable circular opening is present known as pupil. Thus, the option [B] is incorrect.

> Option D:
The Optic Nerve is present at the back side of the eye. It is also known as cranial nerve or second cranial nerve. This nerve helps in transferring the visual information from the retina to the visual center in the brain through electric impulse. Thus, option [D] is incorrect.

> Option C:
The Retina is a thin tissue layer that is present on the inner back side of the human eye. It is present near the optical nerve. Therefore, it can be concluded that photoreceptor cells are present on the retina, which aids in converting the light signals which then passes to the optic nerve.
Hence, the correct answer is option (C).

Note: The retina consists of millions of cells which are sensitive to light. These cells are mainly divided into cones and rods, and they are a type of photoreceptor cells. The vision could get permanently damaged if the retina is damaged.