The cilia in Paramecium are

Options

A. All equal
B. All unequal
C. Longer at posterior end
D. Longer at anterior end

Answer

To solve the question regarding the cilia in Paramecium, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Cilia**: Cilia are hair-like structures that cover the surface of Paramecium. They play a crucial role in locomotion and feeding.

2. **Distribution of Cilia**: In Paramecium, cilia are distributed all over the body. However, their length varies depending on the location on the organism.

3. **Cilia at the Posterior End**: At the extreme posterior end of Paramecium, the cilia are longer and form a structure known as the "caudal tuft." This tuft helps in movement and stability.

4. **Cilia on the Body Surface**: While the cilia at the posterior end are longer, the cilia covering the rest of the body are generally equal in size.

5. **Analyzing the Options**:
- **Option 1**: "All equal" - This is incorrect because the cilia at the posterior end are longer.
- **Option 2**: "All unequal" - This is also incorrect as the cilia on the body surface are equal in length.
- **Option 3**: "Longer at posterior end" - This is correct as the cilia at the posterior end are indeed longer.
- **Option 4**: "Longer at anterior end" - This is incorrect since the longer cilia are at the posterior end, not the anterior.

6. **Conclusion**: The correct answer is **Option 3: Longer at posterior end**.