Inheritance would be extranuclear in case of

Options

A. Killer Paramecium
B. Killer Amoeba
C. Euglena
D. Hydra

Answer

### Step-by-Step Solution:

1. **Understanding Extranuclear Inheritance**:
- Extranuclear inheritance refers to the transmission of genetic material that occurs outside the nucleus. This typically involves organelles such as mitochondria and chloroplasts, which have their own DNA.

2. **Identifying the Organisms**:
- The question provides four options: killer paramecium, killer amoeba, euglena, and hydra. We need to determine which of these organisms exhibit extranuclear inheritance.

3. **Analyzing Killer Paramecium**:
- Killer paramecium, specifically the strain known as Paramecium aurelia, is known to contain kappa particles. These kappa particles are responsible for cytoplasmic inheritance as they contain their own DNA and can replicate independently.

4. **Role of Kappa Particles**:
- Kappa particles secrete a toxin called paramecin, which can kill sensitive strains of paramecium. This trait is inherited cytoplasmically, making killer paramecium a prime example of extranuclear inheritance.

5. **Evaluating Other Options**:
- **Killer Amoeba**: There is no evidence that amoeba exhibit extranuclear inheritance through similar mechanisms as paramecium.
- **Euglena**: While euglena has chloroplasts, it does not exhibit the specific extranuclear inheritance related to kappa particles.
- **Hydra**: Hydra is a multicellular organism that primarily relies on nuclear inheritance.

6. **Conclusion**:
- Based on the analysis, the only organism from the options that exhibits extranuclear inheritance is the killer paramecium.

### Final Answer:
The correct option is **killer paramecium**.

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