Which one is photosensitives in mammals?

Options

A. Retinol
B. Rhodopsin
C. Melanin
D. Sclerotin.

Answer

To solve the question "Which one is photosensitive in mammals?", we will analyze the given options step by step.

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify which of the provided options is photosensitive in mammals. Photosensitivity refers to the ability to respond to light.

2. **Evaluate the Options**:
- **Option 1: Retinol**:
- Retinol is a form of Vitamin A.
- It is important for various bodily functions, including vision, but it is not directly a photosensitive compound.
- **Conclusion**: Incorrect option.

- **Option 2: Rhodopsin**:
- Rhodopsin is a photopigment found in the rod cells of the retina.
- It is crucial for vision in low light conditions as it absorbs light and triggers the visual signal.
- **Conclusion**: This is the correct option as it is directly involved in photosensitivity.

- **Option 3: Melanin**:
- Melanin is a pigment responsible for the color of skin, hair, and eyes.
- While it provides some protection against UV light, it is not a photosensitive molecule involved in vision.
- **Conclusion**: Incorrect option.

- **Option 4: Sclerotin**:
- Sclerotin is a structural protein found in the cuticle of insects.
- It does not have any role in photosensitivity in mammals.
- **Conclusion**: Incorrect option.

3. **Final Conclusion**: The only photosensitive compound among the options provided is **Rhodopsin**. Thus, the correct answer is **Option 2: Rhodopsin**.