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Good vision depends on adequate intake o...

Good vision depends on adequate intake of carotene rich food. Select the best option from the following statements: (a) Vitamin A derivateves are formed from carotene (b) Photopigments are embedded in the membrane discs of inner segment(c ) Retinal is derivative of v itamin A (d) Retinal is a light absorbing part of all the visual pigments.

A

a and b

B

a,c and d

C

a and c

D

b,c and b.

Text Solution

Verified by Experts

The correct Answer is:
B
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A list of steps involved in mechanism of vision is given below in a random order. (i)Neural impulses are analysed and image formed on retina is recognised by visual cortex. (ii)Membrane permeability changes (iii)Ganglion cells are excited (iv)Bipolar cells are depolarised (v)Action potentials (impulse) are transmitted by optic nerves to visual cortex. (vi)Potential differences are generated in the photoreceptor cells. (vii)Light energy causes a change in shape of rhodopsin, leading to the dissociation of retina (an aldehyde of vitamin A ) from opsin (a protein) (viii)Structure of opsin is changed. Which of the following options represents these events in a correct order ?

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