The middle sterile portion in the capsule of moss (Funaria) is

Options

A. Columella
B. Foot
C. Spore sac
D. Protonema.

Answer

To answer the question about the middle sterile portion in the capsule of moss (Funaria), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Moss**:
- Mosses, including Funaria, have a structure called a capsule, which is part of the sporophyte generation. The capsule contains reproductive structures.

2. **Identify the Components of the Capsule**:
- The capsule has different parts, including the columella, foot, spore sac, and protonema. Each of these parts has a specific function.

3. **Define the Middle Sterile Portion**:
- The term "middle sterile portion" refers to a part of the capsule that does not participate in reproduction.

4. **Analyze the Options**:
- **Option 1: Columella** - This is the central sterile tissue in the capsule that provides support and does not produce spores.
- **Option 2: Foot** - This is the part that connects the capsule to the gametophyte and is involved in nutrient absorption, not sterile.
- **Option 3: Spore sac** - This contains the spores and is therefore not sterile.
- **Option 4: Protonema** - This is the early stage of moss development and is not part of the capsule.

5. **Conclusion**:
- Based on the definitions and functions of the parts, the middle sterile portion in the capsule of moss (Funaria) is the **Columella**. Therefore, the correct answer is **Option 1**.

### Final Answer:
The middle sterile portion in the capsule of moss (Funaria) is **Columella**.

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