In Platyhelminthes

Options

A. The embryonic layers, ectoderm and endoderm, are separated by mesoglea
B. The body is asymmetrical
C. There is tissue level of organization
D. The body cavity is absent

Answer

**Step-by-Step Solution:**

1. **Understanding Platyhelminthes**: Platyhelminthes, commonly known as flatworms, are a group of invertebrates characterized by their flat bodies. They belong to the phylum Platyhelminthes.

2. **Embryonic Layers**: Platyhelminthes have three embryonic germ layers: ectoderm, mesoderm, and endoderm. The mesoderm is the layer that lies between the ectoderm and endoderm.

3. **Body Symmetry**: The body of Platyhelminthes is bilaterally symmetrical, meaning it can be divided into mirror-image halves along a single plane. Therefore, the statement claiming that the body is asymmetrical is incorrect.

4. **Level of Organization**: Platyhelminthes exhibit an organ level of organization, not merely a tissue level. This means they have specialized organs that perform specific functions.

5. **Body Cavity**: Platyhelminthes are acoelomates, meaning they lack a true body cavity (coelom). Thus, the statement claiming that the body cavity is absent is correct.

6. **Conclusion**: Based on the analysis of the statements:
- The first statement about embryonic layers is correct.
- The second statement about body symmetry is incorrect.
- The third statement about the level of organization is incorrect.
- The fourth statement about the absence of body cavity is correct.

Therefore, the correct answer is that the body cavity is absent.

**Final Answer**: The correct statement regarding Platyhelminthes is that the body cavity is absent.

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