The protoplasmic strands connecting the two adjacent plants cells through which exchange of material occur are called.

Options

A. plasmalemma
B. plasmodesmata
C. tonofibrils
D. spindle fibres

Answer

To solve the question regarding the protoplasmic strands connecting two adjacent plant cells through which the exchange of material occurs, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure of Plant Cells**:
- Plant cells are characterized by their cell walls, which are composed of various layers including the primary wall, secondary wall, and middle lamella.

2. **Identifying the Middle Lamella**:
- The middle lamella is the layer that lies between the cell walls of adjacent plant cells. It is rich in pectin and serves as a cementing substance that holds the cells together.

3. **Recognizing Plasmodesmata**:
- Plasmodesmata are microscopic channels that traverse the cell walls of plant cells. They are formed from the middle lamella and allow for the direct exchange of materials (such as nutrients and signaling molecules) between adjacent cells.

4. **Eliminating Other Options**:
- Plasma lemma refers to the plasma membrane of plant cells, which is not responsible for connecting adjacent cells.
- Tonofibrils are cytoplasmic proteins found in epithelial tissues and are not related to plant cell connections.
- Spindle fibers are involved in cell division and do not connect plant cells.

5. **Conclusion**:
- The protoplasmic strands connecting two adjacent plant cells through which the exchange of material occurs are called **plasmodesmata**.

### Final Answer:
The protoplasmic strands connecting two adjacent plant cells through which the exchange of material occurs are called **plasmodesmata**.

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