The overarching secondary wall which encloses a part of the pit cavity is called

Options

A. pit border
B. pit membrane
C. pit aperture
D. pit canal

Answer

To solve the question regarding the overarching secondary wall that encloses a part of the pit cavity, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure of Pits**:
- Pits are cavities formed in the secondary cell wall due to uneven deposition of wall materials. They can vary in shape and size.

2. **Types of Pits**:
- There are two main types of pits: simple pits and bordered pits. Bordered pits have a rim or border and are more complex in structure.

3. **Identifying the Overarching Structure**:
- In bordered pits, the secondary wall develops over the pit cavity, creating an overarching structure. This structure is crucial for the function of the pit.

4. **Defining the Terms**:
- The options provided are:
- **Pit Border**: The outer structure that encloses the pit cavity.
- **Pit Membrane**: The inner layer of the pit.
- **Pit Aperture**: The openings in the pit canal.
- **Pit Canal**: The canal formed between the cell lumen and the pit chamber.

5. **Conclusion**:
- The overarching secondary wall that encloses a part of the pit cavity is referred to as the **Pit Border**.

### Final Answer:
The overarching secondary wall which encloses a part of the pit cavity is called the **Pit Border**.

---