The masses of bacteria held together by slime and fungal filaments to form mesh-like structures are called as

Options

A. primary sludge
B. floces
C. activated sludge
D. anaerobic sludge

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term that describes masses of bacteria that are held together by slime and fungal filaments, forming mesh-like structures.

2. **Analyzing the Options**:
- **Option 1: Primary Sludge**: This is a byproduct of the primary treatment of wastewater, consisting of settled solids. It does not refer to the mesh-like structures formed by bacteria and fungi. Therefore, this option is incorrect.
- **Option 2: Flocs**: Flocs are indeed aggregates of bacteria and other microorganisms that are held together by slime and fungal filaments, creating a mesh-like structure. This option appears to be correct.
- **Option 3: Secondary Sludge**: This is produced during the secondary treatment of wastewater, consisting of microorganisms that have been removed from the water. It does not refer to the mesh-like structure described in the question. Thus, this option is incorrect.
- **Option 4: Activated Sludge**: This refers to a mixture of microorganisms used in the secondary treatment of wastewater. While it involves bacteria, it does not specifically describe the mesh-like structure formed by slime and fungal filaments. Therefore, this option is also incorrect.

3. **Conclusion**: Based on the analysis, the correct answer is **Flocs**, as they are the masses of bacteria held together by slime and fungal filaments, forming the mesh-like structures described in the question.

**Final Answer**: Flocs

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