Gastrodermis of Hydra is mainly made of
(a) Musculoepithelial cell
(b) Musculonutritive cells
(c) Sensory cells
(d) Cnidoblast cells.

Options

A. Musculoepithelial cell
B. Musculonutritive cells
C. Sensory cells
D. Cnidoblast cells.

Answer

To solve the question regarding the composition of the gastrodermis of Hydra, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure**: The gastrodermis is a layer that lines the gut of Hydra. It plays a crucial role in digestion and nutrient absorption.

2. **Identify the Cell Types**: The options provided are:
- (a) Musculoepithelial cells
- (b) Musculonutritive cells
- (c) Sensory cells
- (d) Cnidoblast cells

3. **Analyze Each Option**:
- **Musculoepithelial cells**: These are cells that provide structural support and may have some muscular function, but they are not specifically known for nutrition.
- **Musculonutritive cells**: These cells are specialized for both muscle contraction and nutrient absorption. They help in the movement of water and nutrients within the gastrovascular cavity.
- **Sensory cells**: These cells are involved in sensing the environment but do not play a role in digestion.
- **Cnidoblast cells**: These are specialized cells that contain nematocysts (stinging cells) used for defense and capturing prey, not for digestion.

4. **Determine the Correct Answer**: Since the gastrodermis is primarily involved in digestion and nutrient absorption, the most appropriate choice is (b) Musculonutritive cells. These cells are integral to the function of the gastrodermis in Hydra.

5. **Conclusion**: Therefore, the gastrodermis of Hydra is mainly made of **musculonutritive cells**.

### Final Answer:
(b) Musculonutritive cells

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