A pit is unthickened area in cell wall. It lacks

Options

A. primary wall
B. middle Lamella
C. secondary wall
D. cell wall and cell membrane

Answer

**Step-by-Step Solution:**

1. **Understanding the Concept of Pits:**
- A pit is defined as an unthickened area in the cell wall. It allows for communication and exchange of fluids between adjacent cells.

2. **Components of a Pit:**
- A pit consists of three main parts:
- **Pit Chamber:** This is the hollow part of the pit.
- **Pit Aperture:** This is the opening or pore of the pit chamber.
- **Pit Membrane:** This is made up of the primary wall and the middle lamella.

3. **Identifying the Absence in Pits:**
- The question asks what is lacking in a pit. Since pits are unthickened areas, they do not have a secondary wall.

4. **Evaluating the Options:**
- **Option 1: Primary Wall** - This is present in the pit membrane.
- **Option 2: Middle Lamella** - This is also present in the pit membrane.
- **Option 3: Secondary Wall** - This is absent in the pit.
- **Option 4: Cell Wall and Cell Membrane** - These are not absent; they are present in the overall structure.

5. **Conclusion:**
- The correct answer is that a pit lacks the **secondary wall**.

**Final Answer:**
- A pit is an unthickened area in the cell wall, and it lacks the **secondary wall**.

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