Which of the following statements is correct ?

Options

A. Round worms (aschelminthes) are pseudocoelomates
B. Molluscs are acoelomates
C. Insects are pseudocoelomates
D. Flatworms (platyhelminthes) are coelomates

Answer

To determine which of the statements provided is correct, we need to analyze the classification of the organisms mentioned based on their body cavity types: coelomates, acoelomates, and pseudocoelomates.

### Step-by-Step Solution:

1. **Understanding Coelom Types**:
- **Coelomates**: Animals that possess a true coelom, which is a body cavity completely lined by mesoderm. Examples include annelids, mollusks, and vertebrates.
- **Acoelomates**: Animals that lack a body cavity. Examples include flatworms (Platyhelminthes).
- **Pseudocoelomates**: Animals that have a pseudocoelom, which is a body cavity not completely lined by mesoderm. Examples include roundworms (Nematodes).

2. **Analyzing Each Statement**:
- **Roundworms**: They are classified as pseudocoelomates because they have a pseudocoelom situated between the mesoderm and endoderm.
- **Mollusks**: They are not acoelomates; they are true coelomates.
- **Insects**: They are also coelomates, not pseudocoelomates.
- **Flatworms**: They are acoelomates, not coelomates.

3. **Conclusion**:
- The statement that roundworms are pseudocoelomates is correct. Therefore, this is the correct statement among the options provided.

### Final Answer:
The correct statement is: **Roundworms are pseudocoelomates.**

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