Which component of cell wall is normally in contact with plasmalemma

Options

A. primary wall
B. Secondary wall
C. Plasmodesmata
D. Middle lamella

Answer

To answer the question "Which component of the cell wall is normally in contact with the plasmalemma?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of the Cell Wall**:
- The cell wall is a rigid structure that surrounds the cell membrane (plasmalemma) in plant cells, fungi, and bacteria. It is composed of various layers.

2. **Identify the Layers of the Cell Wall**:
- The main components of the cell wall include:
- **Primary Wall**: The outermost layer that is thin and flexible.
- **Secondary Wall**: Located inside the primary wall, it is thicker and more rigid.
- **Middle Lamella**: A layer that contains pectins and acts as a cementing substance between the walls of adjacent cells.

3. **Determine Which Layer Contacts the Plasmalemma**:
- The primary wall is the outermost layer and does not directly contact the plasmalemma.
- The middle lamella serves as a glue between cells but is not in direct contact with the plasmalemma.
- The secondary wall, being the innermost layer, is in direct contact with the plasmalemma.

4. **Conclude the Answer**:
- Based on the above understanding, the component of the cell wall that is normally in contact with the plasmalemma is the **Secondary Wall**.

### Final Answer:
The component of the cell wall that is normally in contact with the plasmalemma is **B. Secondary Wall**.

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