Plasmodesmata often has ER (endoplasmic reticulum) tubule called as
(a) Symplasm
(b) Desmotubule
(c) Apoplasm
(d) Intermediate filaments

Options

A. Symplasm
B. Desmotubule
C. Apoplasm
D. Intermediate filaments

Answer

To solve the question about what the ER tubule in plasmodesmata is called, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the name of the ER tubule found within plasmodesmata.

2. **Define Plasmodesmata**: Plasmodesmata are microscopic channels that traverse the cell walls of plant cells, allowing for transport and communication between them.

3. **Identify the Structure**: Within plasmodesmata, there is a specific structure that is derived from the endoplasmic reticulum (ER).

4. **Know the Options**: The options provided are:
- (a) Symplasm
- (b) Desmotubule
- (c) Apoplasm
- (d) Intermediate filaments

5. **Analyze Each Option**:
- **Symplasm**: This refers to the cytoplasmic continuum of plant cells, not specifically the ER tubule.
- **Desmotubule**: This is the correct term for the ER tubule that runs through plasmodesmata.
- **Apoplasm**: This refers to the cell wall and intercellular spaces, not the ER.
- **Intermediate filaments**: These are part of the cytoskeleton, unrelated to plasmodesmata.

6. **Select the Correct Answer**: Based on the definitions and analysis, the correct answer is (b) Desmotubule.

### Final Answer:
(b) Desmotubule

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