The muscles beneath the epidermis in Ascaris is /are

Options

A. Both longitudinal and circular muscles
B. Only longitudinal muscles
C. Inner circular and outer longitudinal muscles
D. Outer circular and inner longitudinal muscles

Answer

**Step-by-Step Solution:**

1. **Identify the Organism**: The question refers to Ascaris, which belongs to the phylum Aschelminthes (also known as Nematoda).

2. **Understand the Body Structure**: Ascaris has a unique body structure characterized by the presence of a pseudocoelom. This means that the body cavity is not entirely lined by mesoderm, which is a key feature of this organism.

3. **Muscle Layers**: In Ascaris, the muscle layers are located beneath the epidermis. It is important to note that there are two types of muscle arrangements typically found in many organisms: longitudinal and circular muscles.

4. **Muscle Composition in Ascaris**: In Ascaris, only longitudinal muscles are present beneath the epidermis. Circular muscles are absent. This is due to their parasitic lifestyle, where they do not require extensive movement to obtain food, as they absorb nutrients directly from the host's intestinal lumen.

5. **Conclusion**: Therefore, the muscles beneath the epidermis in Ascaris are longitudinal muscles only.

**Final Answer**: The muscles beneath the epidermis in Ascaris are longitudinal muscles.

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