In Amoeba and Hydra, respiration takes place through ________

Explanation

**Step-by-Step Solution:**

1. **Identify the Organisms**: The question refers to two organisms: Amoeba and Hydra. Amoeba is a unicellular organism, while Hydra is a multicellular organism.

2. **Understand the Respiration Process**: Both organisms perform respiration, which is essential for their survival. Respiration involves the exchange of gases, primarily oxygen and carbon dioxide.

3. **Define the Mechanism of Respiration**: The process of respiration in both Amoeba and Hydra occurs through a mechanism called diffusion.

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