Pigment mainly responsible for photosynthesis in red algae is

Options

A. Phycoerythrin
B. Chlorophyll a
C. Carotene
D. Xanthophyll.

Answer

**Step-by-Step Solution:**

1. **Identify the Types of Algae**: Understand that algae can be classified into three main groups: green algae, brown algae, and red algae. Each group has its own specific pigments responsible for photosynthesis.

2. **Recognize the Universal Pigment**: All types of algae contain chlorophyll, which is the universal pigment for photosynthesis. However, the specific types of chlorophyll can vary among the groups:
- Green algae have chlorophyll A and B.
- Brown algae have chlorophyll A and C.
- Red algae have chlorophyll A and D.

3. **Focus on Red Algae**: The question specifically asks about red algae. While chlorophyll is present, red algae also contain accessory pigments that contribute to their color and photosynthetic ability.

4. **Identify Accessory Pigments in Red Algae**: In red algae, the primary accessory pigment is phycoerythrin, which gives the algae its red color. However, it is important to note that phycoerythrin is present in moderate amounts compared to chlorophyll.

5. **Determine the Main Pigment for Photosynthesis**: Although phycoerythrin contributes to the photosynthetic process, chlorophyll A is the main pigment responsible for photosynthesis in red algae because it is present in larger quantities.

6. **Conclusion**: Therefore, the pigment mainly responsible for photosynthesis in red algae is chlorophyll A.

**Final Answer**: Chlorophyll A

---