Which one of the following is the correct difference between rod cells and cone cells of our retina?
- array|l|l|l| & Rod cells & Cone cells \ Overall function & Vision in poor light & Colour vision and detailed vision in bright light \ array
- array|l|l|l| & Rod cells & Cone cells \ Distribution & More concentrated in centre of retina & Evenly distributed all over retina \ array
- array|l|l|l| & Rod cells & Cone cells \ Visual acuity & High & Low \ array
- array|l|l|l| & Rod cells & Cone cells \ Visual pigment contained & Iodopsin & Rhodopsin \ array
Answer
(1) array|l|l|l| & Rod cells & Cone cells \ Overall function & Vision in poor light & Colour vision and detailed vision in bright light \ array
Solution
As per NCERT, rods contain rhodopsin (visual purple) and are responsible for twilight (scotopic) vision, i.e., vision in poor light.
Cones contain iodopsin and are responsible for daylight (photopic) vision and colour vision; the fovea, with only cones, is the point of greatest visual acuity.
(2) is wrong: cones are concentrated in the centre (fovea); rods are more in the periphery.
(3) is wrong: visual acuity is high for cones, low for rods.
(4) is wrong: rods contain rhodopsin, cones contain iodopsin.
Answer: (1)