Question

How many types of cones are present which are responsible for the color differentiation?
A. Only one
B. 7 types for seven fundamental colors
C. 3 types
D. 6 types

Answer 1

Hint: Cones are photoreceptors present in the retina of eyes along with rods. Cones have opsin as their visual pigment. They are responsible for color vision and they function best in bright light.

Complete answer:
Cones are a type of photoreceptors present in the retina of vertebrates and humans. They are concentrated in the center of the retina called fovea centralis. They are responsible for color vision and work best in bright light. They vary from 6-7 million in number. There are three types of cones:
Red cones (also known as L-cones)- they are sensitive to long wave light and account for 64% of the total.
Green cone (also known as M-cones)- they are sensitive to medium wave light and account for 32% of the total.
Blue cones (also known as S-cones)- they are sensitive to short wave light and account for 2-7% of the total.
The cones have a special visual photo-pigment protein called opsin. Red cones have L-opsin, green cones have M-opsin and blue cones have S-opsin. These proteins are essential for capturing light. These opsin pigments capture light and convert light energy into chemical energy, this process is called phototransduction.

Hence, the correct answer to this question is option ‘C’- three.

Note: If there’s a problem with cone cells in eyes, one cannot see all the colors properly and this leads to a condition called color blindness. If one or more cone photopigments are missing, one might have trouble seeing certain colors but if all the cone pigments are missing, one cannot see any color at all and this condition is called achromatopsia.