Which of the following organisms has no specialized respiratory organs ?

Options

A. Tadpole of frog
B. Cockroach
C. Earthworm
D. Mosquito larva

Answer

To determine which organism has no specialized respiratory organs, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the Organisms**: The question provides four options:
- Tadpole of Frog
- Cockroach
- Earthworm
- Mosquito larva

2. **Analyze the Tadpole of Frog**:
- Tadpoles are aquatic and have gills for respiration. As they develop into frogs, they eventually develop lungs.
- **Conclusion**: Tadpole of Frog has specialized respiratory organs (gills).

3. **Analyze the Cockroach**:
- Cockroaches possess a tracheal system, which consists of a network of tubes that facilitate gas exchange directly with their tissues.
- **Conclusion**: Cockroach has specialized respiratory organs (trachea).

4. **Analyze the Earthworm**:
- Earthworms do not have specialized respiratory organs. They respire through their moist skin, where gas exchange occurs directly with the environment.
- **Conclusion**: Earthworm has no specialized respiratory organs.

5. **Analyze the Mosquito Larva**:
- Mosquito larvae have a siphon that allows them to breathe air from the surface of the water, which can be considered a specialized structure for respiration.
- **Conclusion**: Mosquito larva has specialized respiratory organs (siphon).

6. **Final Conclusion**:
- Among the options provided, the Earthworm is the only organism that does not have specialized respiratory organs. Therefore, the correct answer is **Earthworm**.

### Final Answer:
**Earthworm** has no specialized respiratory organs.

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