Animals belonging to playhelmintes are also called . Flat worms because

Options

A. their head is flat
B. they have dorsoventrally compressed body
C. they creep over surface
D. the alimentery canal is flattened .

Answer

**Step-by-Step Solution:**

1. **Understanding the Classification**: Animals belonging to the phylum Platyhelminthes are commonly referred to as flatworms. This classification is based on specific physical characteristics.

2. **Analyzing the Options**:
- **Option 1**: "Their head is flat." - While some flatworms may have a flat head, this is not the defining characteristic of the entire group.
- **Option 2**: "They have dorsoventrally compressed body." - This option describes the overall body structure of flatworms accurately. They are indeed flattened from the dorsal (top) to the ventral (bottom) side.
- **Option 3**: "They creep over surface." - While flatworms may move across surfaces, this is not a unique characteristic that defines them as flatworms.
- **Option 4**: "Their alimentary canal is flattened." - This is not a correct description as not all flatworms have an alimentary canal, and it does not define the group.

3. **Conclusion**: The most accurate reason why animals belonging to Platyhelminthes are called flatworms is due to their dorsoventrally compressed body structure. Therefore, the correct answer is **Option 2**.

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