Regarding simple pits, the true statement is

Options

A. Secondary wall arches over the pit chamber
B. Diameter of pit chamber is uniform throughout
C. Diameter of pit aperture is bigger than that of pit cavity
D. They are formed over the primary pit field only

Answer

To solve the question regarding simple pits, let’s break down the information step by step.

### Step-by-Step Solution:

1. **Understanding Pits**:
- A pit refers to a thin region found in the primary cell wall of a plant. It is important to recognize that pits are structural features that facilitate communication and transport between plant cells.

2. **Types of Pits**:
- There are two main types of pits: simple pits and bordered pits. Simple pits are less complex than bordered pits, which consist of two distinct parts: the torus (an impermeable region) and the margo (a permeable region).

3. **Characteristics of Simple Pits**:
- Simple pits are characterized by their uniformity in size throughout the plant cell wall. This uniform diameter is crucial for maintaining the structural integrity and rigidity of the cell wall.

4. **Analyzing the Options**:
- The options provided in the question are:
1. Secondary wall arches over a pit chamber.
2. Diameter of pit chamber is uniform throughout.
3. Diameter of pit aperture is bigger than that of pit cavity.
4. They are formed over primary pit fields only.

5. **Identifying the True Statement**:
- Based on the understanding of simple pits, the correct statement is: "Diameter of pit chamber is uniform throughout." This is consistent with the characteristics of simple pits.

6. **Conclusion**:
- Therefore, the true statement regarding simple pits is option 2: "Diameter of pit chamber is uniform throughout."