Exchange of respiratory gases takes place in an earthworm through

Options

A. moist skin
B. gills
C. trachea
D. lungs

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks how earthworms exchange respiratory gases. This involves identifying the structure or method used by earthworms for respiration.

2. **Identifying the Options**: The options provided are:
- A) Moist skin
- B) Gills
- C) Trachea
- D) Lungs

3. **Analyzing Each Option**:
- **A) Moist skin**: Earthworms have a moist skin that allows for the exchange of gases. Oxygen from the environment diffuses into their body through the skin, and carbon dioxide diffuses out.
- **B) Gills**: Gills are used by aquatic animals, such as fish, for respiration. Earthworms do not have gills.
- **C) Trachea**: Trachea are respiratory structures found in insects, not in earthworms.
- **D) Lungs**: Lungs are respiratory organs found in mammals, including humans. Earthworms do not possess lungs.

4. **Conclusion**: Based on the analysis, the correct method of gas exchange in earthworms is through their moist skin.

5. **Final Answer**: The exchange of respiratory gases in an earthworm takes place through **moist skin**.

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