Which of the following statements are incorrect?
(i) Parapodia are lateral appendages in arthropods used for swimming.
(ii) Radula in molluscs are structures involved in excretion.
(iii) Aschelminthes are dioecious.
(iv) Echinoderm adults show radial symmetry.
(v) Ctenophorans are diploblastic

Options

A. (a) I and II
B. (b) I and III
C. (c) I, IV and V
D. (d) III and V

Answer

To determine which statements are incorrect, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement (i): Parapodia are lateral appendages in arthropods used for swimming.**
- **Analysis:** Parapodia are actually found in annelids (like earthworms) and some molluscs, not in arthropods. They are fleshy outgrowths that serve various functions, including locomotion and respiration.
- **Conclusion:** This statement is **incorrect**.

2. **Statement (ii): Radula in molluscs are structures involved in excretion.**
- **Analysis:** The radula is a specialized feeding organ in molluscs, used for scraping or cutting food. It is not involved in excretion.
- **Conclusion:** This statement is **incorrect**.

3. **Statement (iii): Aschelminthes are dioecious.**
- **Analysis:** Aschelminthes, also known as roundworms, typically have separate male and female individuals, meaning they are dioecious.
- **Conclusion:** This statement is **correct**.

4. **Statement (iv): Echinoderm adults show radial symmetry.**
- **Analysis:** Adult echinoderms (like starfish) exhibit pentaradial symmetry, while their larvae show bilateral symmetry.
- **Conclusion:** This statement is **correct**.

5. **Statement (v): Ctenophorans are diploblastic.**
- **Analysis:** Ctenophorans (comb jellies) have two germ layers: ectoderm and endoderm, and lack a mesoderm, making them diploblastic.
- **Conclusion:** This statement is **correct**.

### Summary of Findings:
- Incorrect Statements: (i) and (ii)
- Correct Statements: (iii), (iv), and (v)

### Final Answer:
The incorrect statements are (i) and (ii).

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