Which one of the following structures between two adjacent cells is an effective transport pathway ?

Options

A. Plasmalemma
B. Plasmodesmata
C. Plastoquinones
D. Endoplasmic reticulum

Answer

To answer the question "Which one of the following structures between two adjacent cells is an effective transport pathway?", we will analyze the options provided step by step:

### Step 1: Understand the Question
The question requires identifying a structure that serves as a transport pathway between two adjacent cells. This means we are looking for a connection that allows substances to move from one cell to another.

### Step 2: Analyze the Options
1. **Plasma Lemma (Cell Membrane)**:
- The plasma lemma, or plasma membrane, is the outer boundary of a cell.
- It is selectively permeable, allowing certain substances to pass through, but it does not connect two adjacent cells directly.
- **Conclusion**: This is not an effective transport pathway between two cells.

2. **Plasmodesmata**:
- Plasmodesmata are cytoplasmic bridges that connect adjacent plant cells.
- They allow for the direct transport of substances (like ions, nutrients, and signaling molecules) between the cytoplasm of two adjacent cells.
- **Conclusion**: This is indeed an effective transport pathway between two adjacent cells.

3. **Plastoquinone**:
- Plastoquinones are molecules involved in photosynthesis, located in chloroplasts.
- They do not serve as a structural connection between cells and are not involved in cell-to-cell transport.
- **Conclusion**: This is not a transport pathway between cells.

4. **Endoplasmic Reticulum (ER)**:
- The ER is an organelle that facilitates transport within a single cell, not between adjacent cells.
- It provides a framework for intracellular transport but does not connect two cells.
- **Conclusion**: This is not an effective transport pathway between cells.

### Step 3: Final Conclusion
Based on the analysis, the only structure that serves as an effective transport pathway between two adjacent cells is **Plasmodesmata**.

### Answer:
**Plasmodesmata**

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