Epidermis of a sponge is called

Options

A. pinacoderm
B. mesoderm
C. choanoderm
D. none of these

Answer

To answer the question "Epidermis of a sponge is called," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Sponges**:
- Sponges are simple organisms that belong to the phylum Porifera. They have a unique body structure that includes various layers of cells.

2. **Identify the Layers of Sponge**:
- The body of a sponge consists of three main layers: the outer layer (epidermis), the middle layer (mesohyl), and the inner layer (choanoderm).

3. **Focus on the Epidermis**:
- The outer layer of the sponge is referred to as the epidermis. This layer is crucial as it forms the protective covering of the sponge.

4. **Know the Specific Cells in the Epidermis**:
- The epidermis of a sponge is made up of specialized cells called pinacocytes. These cells are thin and flattened, contributing to the structure of the epidermis.

5. **Name the Epidermis**:
- Due to the presence of pinacocytes, the epidermis of sponges is specifically called the "pinacoderm."

6. **Select the Correct Option**:
- Given the options:
- A) Pinacoderm
- B) Mesoderm
- C) Choanoderm
- D) None of these
- The correct answer is option A, as the epidermis of a sponge is indeed called the pinacoderm.

### Final Answer:
The epidermis of a sponge is called **pinacoderm** (Option A).

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