A research scholar once collected some alga and found that its cells contained chlorophyll d and phycocrythrin. the alga must belong to

Options

A. cyanophyceae
B. Chlorophyceae
C. bacillariophyceae
D. rhodophyceae

Answer

To determine the classification of the alga collected by the research scholar, we need to analyze the pigments present in the cells of the alga. The alga contains chlorophyll d and phycocyanin, which are key indicators of its classification.

### Step-by-Step Solution:

1. **Identify the pigments present**: The alga contains chlorophyll d and phycoerythrin. These pigments are crucial for determining the classification of the alga.

2. **Examine the options**: The options provided are:
- Cyanophyceae (Blue-green algae)
- Chlorophyceae (Green algae)
- Bacillariophyceae (Diatoms)
- Rhodophyceae (Red algae)

3. **Analyze Cyanophyceae**: This group, also known as blue-green algae, primarily contains chlorophyll a. They do not contain phycoerythrin, so this option can be eliminated.

4. **Analyze Chlorophyceae**: This group consists of green algae, which typically contain chlorophyll a and b. They also do not contain phycoerythrin, so this option can also be eliminated.

5. **Analyze Bacillariophyceae**: This group includes diatoms, which are unicellular algae. They mainly contain chlorophyll a, chlorophyll c, beta-carotene, and fucoxanthin. They do not have phycoerythrin, so this option can be eliminated as well.

6. **Analyze Rhodophyceae**: This group consists of red algae, which are characterized by the presence of chlorophyll a and chlorophyll d. Importantly, they also contain phycoerythrin, which gives them their red color. Since the alga in question contains both chlorophyll d and phycoerythrin, this is the correct classification.

7. **Conclusion**: Based on the analysis, the alga collected by the research scholar must belong to the group Rhodophyceae (Red algae).

### Final Answer:
The alga must belong to **Rhodophyceae**.