Which one of the following categories of organisms do not evolve oxygen during Photosynthesis

Options

A. Red algae
B. Photosynthetic bacteria
C. `C_(4)` plants with Kranz anatomy
D. Blue green algae

Answer

To solve the question "Which one of the following categories of organisms do not evolve oxygen during photosynthesis?", we will analyze each option provided and determine whether they produce oxygen as a by-product during photosynthesis.

### Step-by-Step Solution:

1. **Understanding Photosynthesis**:
- Photosynthesis is a process where organisms convert carbon dioxide (CO2) and water (H2O) into glucose using sunlight and chlorophyll. A by-product of this process is oxygen (O2), which is produced from the splitting of water molecules.

2. **Analyzing the Options**:
- **Option 1: Red Algae**:
- Red algae perform oxygenic photosynthesis, meaning they do produce oxygen as a by-product.
- **Option 2: Photosynthetic Bacteria**:
- Photosynthetic bacteria, such as purple and green sulfur bacteria, utilize a process known as anoxygenic photosynthesis. They do not use water as an electron donor, and therefore do not produce oxygen.
- **Option 3: C4 Plants**:
- C4 plants, like maize and sugarcane, also perform oxygenic photosynthesis and produce oxygen.
- **Option 4: Blue-Green Algae**:
- Blue-green algae (cyanobacteria) are known for oxygenic photosynthesis, producing oxygen as a by-product.

3. **Conclusion**:
- The only category of organisms listed that does not evolve oxygen during photosynthesis is **photosynthetic bacteria**. They utilize other compounds (like hydrogen sulfide) instead of water, which is why they do not produce oxygen.

### Final Answer:
**Photosynthetic bacteria** do not evolve oxygen during photosynthesis.

---