The cells absent in gastrodermis of Hydra are

Options

A. Nutritive cells
B. Stinging cells/Cnidoblasts
C. Gland cells
D. Nerve/sensory cells.

Answer

To answer the question about which cells are absent in the gastrodermis of Hydra, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure of Hydra**:
- Hydra is a simple organism belonging to the phylum Cnidaria. It has two main layers: the epidermis (outer layer) and the gastrodermis (inner layer).

2. **Identifying the Function of Gastrodermis**:
- The gastrodermis is primarily involved in digestion and secretion. It contains various types of cells that perform these functions.

3. **Types of Cells Present in Gastrodermis**:
- The gastrodermis includes several types of cells:
- **Nutritive muscular cells**: These cells help in digestion and nutrient absorption.
- **Interstitial cells**: These are stem cells that can differentiate into other cell types.
- **Nerve cells**: These are involved in the nervous system functions.
- **Gland cells**: These cells secrete digestive enzymes.

4. **Identifying the Cells Absent in Gastrodermis**:
- The question specifically asks for the cells that are **absent** in the gastrodermis.
- One notable type of cell in Hydra is the **cnidocytes** (or nematocysts), which are responsible for stinging and defense.
- Cnidocytes are primarily located in the epidermis, particularly on the tentacles, and are not found in the gastrodermis.

5. **Conclusion**:
- Therefore, the cells that are absent in the gastrodermis of Hydra are the **cnidocytes** (stinging cells).

### Final Answer:
The cells absent in the gastrodermis of Hydra are **cnidocytes** (stinging cells).

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