Question

In eyes, the bipolar cells are present in
A. Sclerotic
B. Choroid
C. Retina
D. Yellow spot

Answer 1

Hint: Bipolar cells are neurons that are present at that part of an eye that receives light. Along with bipolar cells, photoreceptors, i.e. rods and cones, and ganglion cells are also present. The bipolar cells transmit signals between the ganglion cells and the photoreceptors. These cells are referred to as bipolar cells because they perform two processes.

Complete answer:
• In the eyes, the bipolar cells are present in the retina.
• The retina is the light-sensitive layer that is present at the back of the eye (present in both eyes). The retina consists of many neurons.
• The photoreceptor cells are light-sensing cells. They are of two types – rods and cones.
• Ganglion cells are photosensitive cells that are also present on the retina.
• The bipolar cells exist between the photoreceptors (rods and cones) and the ganglion cells and transmit signals between them. They either act directly or indirectly.

> Directly:
The bipolar cells can synapse with any one of the photoreceptors and even get synapsed from the horizontal cells. The signal from the photoreceptors/horizontal cells gets transmitted to the ganglion cells by the bipolar cells.

> Indirectly:
In this process, the signal from the photoreceptors/horizontal cells gets transmitted to the ganglion cells via the amacrine cells. Amacrine cells are neurons present on the retina that facilitate the transmission of signals to the ganglion cells.

Hence, the correct answer is option (C).

Note: The rods and the cones function differently. The rods are responsible for a black and white vision, because of which they work in dark. On the other hand, cones are responsible for the perception of colour and function best in the light. Ganglion cells are photosensitive cells that regulate the reflexes of the eye in relation to light as well as the circadian rhythm of the body.