Which one of the following is a matching pair of a body feature and the animal possessing it?

Options

A. Canal system - Asterias
B. Metagenesis - Obelia
C. Dorsal nerve cord - Pheretima
D. Muscular pharynx - Taenia

Answer

To solve the question, we need to identify the correct matching pair of a body feature and the animal that possesses it. Let's analyze each option step by step.

### Step-by-Step Solution:

1. **Analyze Option 1: Canal System and Estuaries**
- The canal system is a network of passages that connects various cavities in certain animals.
- This feature is characteristic of organisms like sponges and corals, not estuaries.
- **Conclusion**: This option is incorrect.

2. **Analyze Option 2: Metagenesis and Obelia**
- Metagenesis refers to the alternation of generations, which includes both sexual and asexual reproduction.
- Obelia is a colonial organism that exhibits metagenesis, alternating between polyp and medusa forms.
- **Conclusion**: This option is correct.

3. **Analyze Option 3: Dorsal Nerve Cord and Pharatema**
- Pharatema (commonly known as earthworm) has a ventral nerve cord, not a dorsal one.
- **Conclusion**: This option is incorrect.

4. **Analyze Option 4: Muscular Firing Switches and Tinea**
- Tinea (tapeworm) does not have muscular firing switches; it has non-muscular structures.
- **Conclusion**: This option is incorrect.

### Final Answer:
The correct matching pair of a body feature and the animal possessing it is **Option 2: Metagenesis and Obelia**.

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