Arrange the following steps of mechanism of vision in order. (1) Light induces dissociation of the retinal from opsin. (2) Change in the structure of opsin. (3) Change in membrane permeability. (4) Potential differences are generated in photoreceptor cells. (5) Generation of AP is ganglion cell through bipolar cells. (6) AP is transmitted via optic nerve to visual cortex. (7) At visual cortex, nerve impulses are analysed and the image formed on retina is recognized based on the earlier memory and experience. (8) Focusing of visible light on retina.
(a) 8,1,2,3,4,5,6,7
(b) 8,1,7,2,6,3,5,4
(c) 1,2,3,4,5,6,7,8
(d) 8,7,6,5,4,3,2,1
Answers
Answer:
Correct option is
D
(vii), (viii), (ii), (vi), (iv), (iii), (v), (i)
The correct order of the mechanism of vision is :
1. Light energy causes a change in the shape of rhodopsin, leading to the dissociation of retinal (an aldehyde of vitamin A) from opsin (a protein).
2. Structure of opsin is changed.
3. membrane permeability changes.
4. The potential difference is generated in the photoreceptor cells.
5. Bipolar cells are depolarized.
6. Ganglion cells are excited.
7. Action potentials (impulse) are transmitted by optic nerves to the visual cortex.
8. Neural impulses are analysed and the image formed on the retina is recognised by visual cortex.
So, the correct answer is 'Option D- (vii),(viii),(ii),(vi),(iv),(iii),(v),(i)'.
Correct option is (a)8,1,2,3,4,5,6,7
(8) Focusing of visible light on retina.
(1) Light induces dissociation of the retinal from opsin.
(2) Change in the structure of opsin.
(3) Change in membrane permeability.
(4) Potential differences are generated in photoreceptor cells.
(5) Generation of AP is ganglion cell through bipolar cells.
(6) AP is transmitted via optic nerve to visual cortex.
(7) At visual cortex, nerve impulses are analysed and the image formed on retina is recognized based on the earlier memory and experience.