Periplast plates of Euglena are

Options

A. Interlocked
B. Pliable
C. Underlined by mucilage and microtubules
D. All the above

Answer

To answer the question about the periplast plates of Euglena, we will analyze the characteristics of these structures step by step.

### Step-by-Step Solution:

1. **Understanding Periplast Plates**:
- The periplast plates, also known as the pellicle, are a layer that covers the body of Euglena. This layer is important for providing shape and protection to the organism.

2. **Structure of the Pellicle**:
- The pellicle is made up of thin, flexible, tough, and strong cuticular plates. It lies just beneath the plasma membrane of the Euglena.

3. **Arrangement of Plates**:
- Electron microscopic studies reveal that the pellicle is composed of helically disposed strips. These strips are fused at both ends of the cell body, which allows for flexibility and movement.

4. **Interlocking Mechanism**:
- Each strip has grooves along its edges, and the edges of neighboring strips overlap. This overlapping arrangement allows the ridges of one strip to fit into the grooves of another, making them interlocked.

5. **Additional Structures**:
- Beneath and parallel to these strips, there are rows of muciferous bodies that secrete mucus, as well as bundles of microtubules. This arrangement contributes to the structural integrity and flexibility of the pellicle.

6. **Conclusion**:
- Given the characteristics discussed, the periplast plates of Euglena can be described as interlocked, pliable, and underlined by muciferous bodies and microtubules. Therefore, the correct answer to the question is "all of the above."

### Final Answer:
The periplast plates of Euglena are interlocked, pliable, and underlined by muciferous bodies and microtubules. Thus, the correct answer is **all of the above**.

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