Protrusible structure present over the scolex of tapeworm is

Options

A. Rostellum
B. Sucker
C. Proglottids
D. Auricle

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure of Tapeworms:**
- Tapeworms, such as Taenia solium (the pork tapeworm), have a body divided into three main parts: the scolex, neck, and strobila.
- The scolex is often mistakenly referred to as the head, but it serves a specific purpose in attachment to the host's intestine.

2. **Identifying the Scolex:**
- The scolex is the anterior part of the tapeworm and is equipped with structures that help the organism attach to the intestinal wall of the host.

3. **Protrusible Structures on the Scolex:**
- The scolex contains a protrusible structure known as the **rostellum**.
- The rostellum is cone-shaped and is located at the tip of the scolex.

4. **Features of the Rostellum:**
- The rostellum is equipped with hooks, typically numbering between 22 to 32.
- These hooks are arranged in two whorls (outer and inner) and are curved, aiding in the attachment of the tapeworm to the host.

5. **Other Structures on the Scolex:**
- In addition to the rostellum, the scolex also has suckers (four cup-shaped structures) that assist in attachment.
- However, the question specifically asks for the protrusible structure, which is the rostellum.

6. **Conclusion:**
- Therefore, the protrusible structure present over the scolex of the tapeworm is the **rostellum**.

**Final Answer:**
The protrusible structure present over the scolex of the tapeworm is the **rostellum**.

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