Hydra can suddenly contract the body by

Options

A. Intestitial cells
B. Epitheliomuscular cells
C. Nematoblasts
D. Nutritive cells

Answer

### Step-by-Step Solution:

1. **Understanding Hydra's Body Structure**: Hydra is a simple organism that has a tubular body structure. It is made up of different types of cells that perform various functions.

2. **Identifying the Function of Cells**:
- **Interstitial Cells**: These cells are responsible for producing nerve cells and nematocysts (stinging cells). They do not play a direct role in the contraction of the body.
- **Epithelial Muscular Cells**: These cells are specialized for movement and contraction. They are responsible for the muscular movements in Hydra, enabling it to contract its body and tentacles.
- **Nematoblast Cells**: These cells produce nematocysts, which are used for capturing prey but do not contribute to body contraction.
- **Nutritive Cells**: These cells are involved in digestion and nutrient absorption, not in body movement.

3. **Determining the Correct Answer**: Since the question asks about the contraction of Hydra's body, the correct answer is the epithelial muscular cells, as they facilitate the contraction and relaxation necessary for movement and feeding.

4. **Final Answer**: Hydra can suddenly contract its body by the action of epithelial muscular cells.