Pellicle in Euglenoids is :

Options

A. proteinaceous bilayer, striped, flexible
B. proteinaceous , striped , rigid
C. cell membrane, unstriped, flexible
D. proteinaceous, striped, flexible

Answer

To answer the question "Pellicle in Euglenoids is:", we will analyze the options provided and determine the correct description of the pellicle in Euglenoids.

### Step-by-Step Solution:

1. **Understanding Pellicle**:
- The pellicle is a unique structure found in Euglenoids, which are a group of single-celled organisms. Unlike many other organisms, Euglenoids do not have a rigid cell wall.

2. **Composition of Pellicle**:
- The pellicle is primarily made up of a proteinaceous layer. This layer is not just a simple membrane; it has a complex structure.

3. **Structure of Pellicle**:
- The pellicle consists of microtubules arranged in a specific pattern. These microtubules provide support and flexibility to the pellicle.

4. **Properties of Pellicle**:
- The pellicle is described as being flexible, allowing the Euglenoids to change shape. This flexibility is essential for their movement and adaptability in various environments.

5. **Analysis of Options**:
- **Option 1**: "Proteinaceous, bilayer, striped and flexible." - This option is incorrect because while it mentions proteinaceous and flexible, the term "bilayer" is misleading in this context.
- **Option 2**: "Proteinaceous, striped and rigid." - This is incorrect because the pellicle is flexible, not rigid.
- **Option 3**: "Cell membrane, unstriped or flexible, and this is the proteinaceous layer." - This option is misleading as it refers to the pellicle as a cell membrane, which is not accurate.
- **Option 4**: "Cell membrane, unstriped or flexible, and this is the proteinaceous layer." - This option is also misleading but is the closest to describing the pellicle's nature.

6. **Conclusion**:
- The correct characterization of the pellicle in Euglenoids is that it is a proteinaceous layer supported by microtubules, which is flexible and allows for movement through a process known as metaboly.

### Final Answer:
The pellicle in Euglenoids is a proteinaceous layer that is flexible and supported by microtubules.