In Hydra, egestion of undigested food and excretion of nitrogenous wastes occur through

Options

A. mouth and mouth
B. body wall and body wall
C. mouth and body wall
D. mouth and tentacles

Explanation

**Step-by-step Solution:**

1. **Understanding Hydra's Anatomy**: Hydra is a simple aquatic organism that lacks specialized organs for excretion. It has a body structure that allows for the diffusion of substances.

2. **Egestion of Undigested Food**: In Hydra, the undigested food is expelled through the mouth. The mouth serves as both the entrance for food and the exit for waste.

3. **Excretion of Nitrogenous Wastes**: The primary nitrogenous waste in Hydra is ammonia. Ammonia is a toxic compound that needs to be excreted efficiently. In Hydra, ammonia diffuses through the general body surface into the surrounding water.

4. **Role of Body Wall**: The body wall of Hydra is permeable and facilitates the diffusion of ammonia. Therefore, both the mouth and the body wall play roles in the excretion process.

5. **Conclusion**: Thus, in Hydra, egestion of undigested food occurs through the mouth, while the excretion of nitrogenous wastes occurs through both the mouth and the body wall.

**Final Answer**: Egestion of undigested food and excretion of nitrogenous wastes in Hydra occur through the mouth and body wall.

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