Proteinaceous pigment which is the centre of the activities concerned with light is

Options

A. phytochrome
B. chlorophyll
C. anthocyarnin
D. carotenoids

Explanation

To answer the question regarding the proteinaceous pigment that is central to activities concerned with light, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Term "Proteinaceous Pigment":**
- The term "proteinaceous" refers to substances that contain proteins. Therefore, we are looking for a pigment that is made up of or associated with proteins.

2. **Identifying the Context of Light Activities:**
- The question implies that this pigment is involved in processes related to light, which often refers to photosynthesis and other light-dependent reactions in plants.

3. **Considering Common Pigments:**
- The primary pigment associated with photosynthesis is chlorophyll. However, chlorophyll is not classified as a proteinaceous pigment, so it cannot be the answer.

4. **Exploring Other Pigments:**
- There are other pigments such as carotenoids, anthocyanins, and xanthophylls, but these are also not proteinaceous.

5. **Identifying Phytochrome:**
- The correct answer is phytochrome, which is indeed a proteinaceous pigment. Phytochrome plays a crucial role in detecting light and regulating various plant responses to light, such as photoperiodism (the response of plants to the length of day and night).

6. **Understanding Phytochrome Functionality:**
- Phytochrome exists in two forms: Pr (red light-absorbing form) and Pfr (far-red light-absorbing form). It can switch between these forms in response to light, thus regulating processes like flowering based on light duration.

7. **Conclusion:**
- Therefore, the proteinaceous pigment that is central to activities concerned with light is **phytochrome**.

### Final Answer:
The proteinaceous pigment which is the center of the activities concerned with light is **phytochrome**.

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