Micronucleus and macronuleus occur in

Options

A. Entamoeba and Plasmodium
B. Entamoeba and Vorticella
C. Paramecium and Vorticella
D. Euglena and Volvax.

Answer

To answer the question regarding where micronucleus and macronucleus occur, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terms**:
- **Micronucleus**: This is a smaller nucleus that is involved in reproductive functions.
- **Macronucleus**: This is a larger nucleus that is polyploid and is involved in metabolic functions and protein synthesis.

2. **Identifying Organisms**:
- The question provides four options of organisms:
1. Amoeba and Plasmodium
2. Amoeba and Verticilla
3. Paramecium and Verticilla
4. Euglena and Volvox

3. **Analyzing Each Option**:
- **Option 1 (Amoeba and Plasmodium)**:
- Amoeba does not have a micronucleus and macronucleus; it has multiple nuclei in its cyst form.
- Plasmodium has multiple nuclei but does not have distinct micronucleus and macronucleus.
- **Option 2 (Amoeba and Verticilla)**:
- Similar to option 1, Amoeba does not fit the criteria.
- **Option 3 (Paramecium and Verticilla)**:
- Both Paramecium and Verticilla are known to have both micronucleus and macronucleus.
- **Option 4 (Euglena and Volvox)**:
- Euglena has one nucleus, and Volvox is a colonial organism with each cell containing one nucleus.

4. **Conclusion**:
- The correct answer is **Option 3: Paramecium and Verticilla**, as both organisms possess dimorphic nuclei consisting of a micronucleus and a macronucleus.

### Final Answer:
Micronucleus and macronucleus occur in **Paramecium and Verticilla**.