Answer briefly :
(a) How do you perceive the colour of an object ?
(b) Which part of our body helps us in maintaining the body balance ?
(c) How does the eye regulate the amount of light that falls on the retina.

Explanation

(a) Photoreceptors are cells that are sensitive to light . They are of two types - rods and cones. These are present in the retina . Cones help in distinguishing colours. There are three types of cone cells - those responding to green light , those responding to blue light , and those responding to red light .
(b) Vestibular apparatus is located in the internal ear , above the cochlea and helps in maintaining body balance.
Crista and macuta are the sensory spots of the vestibular apparatus controlling dynamic equilibrium .
(c) Pupil is the small aperture in the iris that regulates the amount of light entering the eye . Cornea , aqueous humour , lens and vitreous humour act together and refract light rays , focussing them onto the photoreceptor cells of the retina.