Ciliates differ from all other protozoans in

Options

A. (a) having two types of nuclei
B. (b) using pseudopodia for capturing prey
C. (c) having a contractile vacuole for remov- ing excess water
D. (d) using flagella for locomotion

Answer

**Step-by-Step Solution:**

1. **Understand the Question**: The question asks how ciliates differ from all other protozoans. We need to identify a unique characteristic of ciliates.

2. **Identify Key Features of Ciliates**: Ciliates are a group of protozoans that are characterized by the presence of cilia, which are hair-like structures that aid in movement and feeding.

3. **Recognize the Types of Nuclei**: One of the most distinguishing features of ciliates is that they possess two types of nuclei:
- **Macronucleus**: This is the larger nucleus that is responsible for the somatic functions of the cell.
- **Micronucleus**: This is the smaller nucleus that is involved in reproductive functions.

4. **Evaluate the Options**:
- **Option A**: Having two types of nuclei. This is true for ciliates and distinguishes them from other protozoans.
- **Option B**: Using pseudopodia for capturing prey. This is incorrect as ciliates use cilia, not pseudopodia.
- **Option C**: Having a contractile vacuole for removing excess water. While this is true, it is not unique to ciliates as many protozoans have contractile vacuoles.
- **Option D**: Using flagella. This is incorrect since ciliates do not use flagella for movement.

5. **Select the Correct Answer**: Based on the evaluation, the correct answer is **Option A**: Ciliates differ from all other protozoans in having two types of nuclei.

**Final Answer**: Ciliates differ from all other protozoans in having two types of nuclei.

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