Which part of Hydra is without namatoblasts ?

Options

A. Pedal disc
B. Tentacles
C. Manubrium
D. Stomach region.

Answer

### Step-by-Step Solution:

1. **Understanding Hydra and Nematoblasts**:
- Hydra is a type of cnidarian, which are aquatic animals found in both marine and freshwater environments.
- Nematoblasts, also known as stinging cells, are specialized cells in Hydra that contain a coiled, poisonous thread used for capturing prey and self-defense.

2. **Analyzing the Options**:
- The question asks which part of Hydra lacks nematoblasts. The options provided are:
- a) Pedal disc
- b) Tentacles
- c) Manubrium
- d) Stomach region

3. **Examining Each Option**:
- **Pedal Disc**:
- Located at the base of the Hydra, the pedal disc is responsible for attachment to surfaces. It does not have nematoblasts, as its primary function is not related to capturing prey.
- **Tentacles**:
- The tentacles are rich in nematoblasts, as they are primarily used for capturing prey. Therefore, this option is incorrect.
- **Manubrium**:
- The manubrium is the oral part of Hydra and also contains nematoblasts, aiding in prey capture. This option is also incorrect.
- **Stomach Region**:
- Hydra does not possess a true stomach; instead, it has a gastrointestinal cavity. However, this region also contains nematoblasts. Thus, this option is incorrect as well.

4. **Conclusion**:
- The only part of Hydra that is without nematoblasts is the **pedal disc**.

### Final Answer:
The part of Hydra that is without nematoblasts is the **pedal disc**.