Chlorophyll a is absent in which of the following photosynthetic organism

Options

A. Bacteria
B. Cyanobacteria
C. Red algae
D. None of these

Answer

To determine which photosynthetic organism lacks chlorophyll a, we can analyze the options provided: bacteria, cyanobacteria, and red algae.

### Step-by-Step Solution:

1. **Understanding the Organisms**:
- **Cyanobacteria**: Also known as blue-green algae, these organisms are photosynthetic and contain chlorophyll a.
- **Red Algae**: These are also photosynthetic organisms that contain chlorophyll a, along with other pigments that give them their characteristic color.
- **Bacteria**: Some bacteria are photosynthetic, but they do not contain chlorophyll a. Instead, they utilize a different pigment called bacteriochlorophyll.

2. **Analyzing the Options**:
- **Bacteria**: As mentioned, certain groups of bacteria can perform photosynthesis using bacteriochlorophyll and do not have chlorophyll a.
- **Cyanobacteria**: They contain chlorophyll a and are capable of photosynthesis.
- **Red Algae**: They also contain chlorophyll a and are photosynthetic.

3. **Conclusion**:
- Based on the analysis, chlorophyll a is absent in **bacteria**. Therefore, the correct answer to the question is **bacteria**.

### Final Answer:
Chlorophyll a is absent in **bacteria**.

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