Question

Good vision depends on adequate intake of carotene-rich food. Select the best option from the following statements.

I. Vitamin A derivatives are formed from carotene
II. The photopigments are embedded in the membrane discs of the inner segment
III. Retinal is a derivative of vitamin A
IV. Retinal is a light-absorbing part of all the visual photopigments

• A. I, III and IV
• B. I, and III
• C. II, III and IV
• D. I and II

Answer 1

The correct option is A I, III and IV

Retina function is maintained by a protein known as opsin that forms association with retinal. Retinal (aldehyde of vitamin A) is the light sensitive pigment. It is required to form rhodopsin, the photopigment present in rod cells. Vitamin A deficiency that leads to low production of retinal and it is also a cause for poor vision. This deficiency can be overcome by the consumption of fruits and vegetables that contains the carotene pigments. And this carotene pigment is helpful in synthesizing vitamin A derivatives. So, the correct option is “a”- I, III and IV.