Vitamin-A is necessary for the proper physiological function of eye because

Options

A. it is necessary for nerve impulses in retina
B. rhodopsin is made up of vitamin -A
C. oxidation of rhodopsin requires vitamin -A
D. none of the above .

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of Vitamin A in Eye Function:**
- Vitamin A is essential for the proper functioning of the eye. It plays a critical role in the formation of rhodopsin, a light-sensitive pigment found in the retina.

2. **Structure of the Eye:**
- The human eye consists of three main layers:
- **Outer Layer:** Sclera
- **Middle Layer:** Choroid
- **Inner Layer:** Retina

3. **Photoreceptor Cells:**
- The retina contains photoreceptor cells, which are crucial for vision. There are two types of photoreceptor cells:
- **Rods:** Responsible for vision in low light conditions (twilight vision).
- **Cones:** Responsible for color vision and function best in bright light (daylight vision).

4. **Rhodopsin and Vitamin A:**
- Rods contain a pigment called rhodopsin (also known as visual purple), which is a combination of a protein and a derivative of Vitamin A.
- Rhodopsin is essential for the conversion of light into nerve impulses, which are then transmitted to the brain.

5. **Conclusion:**
- Since rhodopsin is made up of Vitamin A and is necessary for the proper physiological function of the eye, the correct answer to the question is that Vitamin A is necessary because rhodopsin is made up of Vitamin A.

**Final Answer:**
Vitamin A is necessary for the proper physiological function of the eye because rhodopsin is made up of Vitamin A.

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