In which of the following the nuclear dimorphism is seen -

Options

A. Entamoeba
B. Leishmania
C. Trypanosoma
D. Paramoecium

Answer

To determine where nuclear dimorphism is observed, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding Nuclear Dimorphism**:
- Nuclear dimorphism refers to the presence of two different types of nuclei within a single organism or cell. This is an important characteristic in certain protozoans.

2. **Analyzing Option 1: Antamoeba**:
- Antamoeba is known to have multiple nuclei, but they are similar in structure and function. Therefore, it does not exhibit nuclear dimorphism.
- **Conclusion**: Antamoeba does not show nuclear dimorphism.

3. **Analyzing Option 2: Leishmania**:
- Leishmania is a genus of parasites that causes diseases like leishmaniasis. It has a well-defined nucleus, but there is no evidence of nuclear dimorphism.
- **Conclusion**: Leishmania does not show nuclear dimorphism.

4. **Analyzing Option 3: Trypanosoma**:
- Trypanosoma is another genus of parasitic protozoa known for causing diseases such as sleeping sickness. It also possesses a well-defined nucleus and does not exhibit nuclear dimorphism.
- **Conclusion**: Trypanosoma does not show nuclear dimorphism.

5. **Analyzing Option 4: Paramecium**:
- Paramecium is a ciliated protozoan that exhibits nuclear dimorphism. It has two types of nuclei: a macronucleus and one or more micronuclei, which serve different functions.
- **Conclusion**: Paramecium shows nuclear dimorphism.

### Final Answer:
The correct answer is **Option 4: Paramecium**.