Anoxygenic and oxygenic photosynthesis are respectively shown by

Options

A. 1. Green algae & algae
B. 2. Red algae & monocots
C. 3. Pigmented sulfur bacteria & cyanobacteria
D. 4. BGA & higher plants

Answer

To answer the question regarding which organisms perform anoxygenic and oxygenic photosynthesis, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Define Photosynthesis**:
- Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy, using carbon dioxide and water. It is generally divided into two types: oxygenic and anoxygenic photosynthesis.

2. **Explain Oxygenic Photosynthesis**:
- Oxygenic photosynthesis is the type of photosynthesis that produces oxygen as a byproduct. This process is primarily carried out by plants, algae, and cyanobacteria. The general equation for oxygenic photosynthesis can be summarized as:
\[ 6CO_2 + 6H_2O + light \ energy \rightarrow C_6H_{12}O_6 + 6O_2 \]

3. **Identify Organisms Performing Oxygenic Photosynthesis**:
- The main organisms that perform oxygenic photosynthesis include:
- Green plants (e.g., trees, shrubs, grasses)
- Algae (e.g., green algae, red algae)
- Cyanobacteria (often referred to as blue-green algae)

4. **Explain Anoxygenic Photosynthesis**:
- Anoxygenic photosynthesis is a type of photosynthesis that does not produce oxygen. Instead, it uses other electron donors, such as hydrogen sulfide (H2S) or organic compounds. This process is typically found in certain bacteria.

5. **Identify Organisms Performing Anoxygenic Photosynthesis**:
- The main organisms that perform anoxygenic photosynthesis include:
- Purple sulfur bacteria (e.g., Chromatium)
- Green sulfur bacteria (e.g., Chlorobium)
- Some species of heliobacteria

6. **Conclusion**:
- In summary, oxygenic photosynthesis is shown by green plants, algae, and cyanobacteria, while anoxygenic photosynthesis is shown by purple sulfur bacteria, green sulfur bacteria, and heliobacteria.

### Final Answer:
- **Anoxygenic photosynthesis** is shown by **purple sulfur bacteria** and **green sulfur bacteria**.
- **Oxygenic photosynthesis** is shown by **green plants**, **algae**, and **cyanobacteria**.

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