Question

Name the cells of the retina and their respective pigments which gets activated (1) in dark and (2) in light.

Answer 1

Retina:

1. The retina is the innermost layer of the eyes.
2. It consists of nervous tissue and connective tissue.
3. It contains two types of photoreceptor cells(rod and cone cells).

Photoreceptors cells:

1. Photoreceptor cells are sensitive to light.
2. They are stimulated by the intensity of the light.
3. The human retina contains two types of photoreceptors cells.
4. They are- Rod cells and Cone cells.

(1) Rod cells:

1. They are rod-shaped cells.
2. The human eyes contain 115 to 120 million rod cells.
3. They contain rhodopsin pigment.
4. Rod cells are responsible for black and white vision.
5. Rod cells help to see objects in dim light at night, which means they can absorb low-intensity light.

(2) Cone cells:

1. These cells are cone-shaped.
2. Human eyes contain 6 to 6.5 million cone cells.
3. They contain the pigment iodopsin.
4. They help us to see objects in bright light.
5. Cone cells are responsible for color vision.

Hence, Rod cells get activated in the dark, and Cone cells get activated in light.