Which one of the following statements is incorrect ?

Options

A. a) In cockroaches and prawns, excretion of waste material occurs through Malpighian tubules.
B. b) In ctenophores, locomotion is mediated by comb plates.
C. c) In Fasciola flame cells take part in excretion
D. d) Earthworm are hermaphrodites and yet cross fertilisation take place among them.

Explanation

To determine which statement is incorrect, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Analyze Statement A**:
- Statement A claims that in cockroaches and prawns, the excretion of waste material occurs through Malpighian tubules.
- In cockroaches, this statement is correct as they do use Malpighian tubules for excretion.
- However, in prawns, the excretion is facilitated by green glands, not Malpighian tubules.
- Therefore, Statement A is **incorrect**.

2. **Analyze Statement B**:
- Statement B states that in ctenophores, locomotion is mediated by cilia (referred to as "complates" in the transcript).
- This statement is correct because ctenophores have specialized structures called ctenes (complates) that help in locomotion.

3. **Analyze Statement C**:
- Statement C mentions that in Planaria (fisiola), flame cells take part in excretion.
- This is also correct, as flame cells are specialized cells in flatworms that are involved in excretion.

4. **Analyze Statement D**:
- Statement D states that earthworms are hermaphrodites, meaning they possess both male and female reproductive organs, and that cross-fertilization occurs among them.
- This statement is accurate because earthworms do have both sex organs but typically engage in cross-fertilization with other earthworms.

5. **Conclusion**:
- After analyzing all statements, we find that Statement A is the only incorrect statement.

### Final Answer:
The incorrect statement is **Statement A**: "In cockroaches and prawns, the excretion of waste material occurs through Malpighian tubules."

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