Which one of the following statements is incorrect?

Options

A. In cockroaches and prawns excretion of waste material occurs through Malpighian tubules.
B. In ctenophores, locomotion is mediated by comb plates.
C. In Fasciola flame cells take part in excretion
D. Earthworms are hermphrodites and yet cross fertilization take place among them.

Answer

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

### Step-by-Step Solution:

1. **Analyze the First Statement:**
- The statement claims that in cockroaches and prawns, the excretion of waste material occurs through the Malpighian tubules.
- **Cockroaches:** This is correct; cockroaches excrete waste through Malpighian tubules.
- **Prawns:** This is incorrect; prawns excrete waste through green glands, not Malpighian tubules.
- **Conclusion:** This statement is incorrect.

2. **Analyze the Second Statement:**
- The statement claims that locomotion is mediated by the "complates."
- **Tina Force:** This refers to the cilia or flagella in certain organisms.
- **Conclusion:** This statement is correct as locomotion in many organisms is indeed mediated by cilia or flagella.

3. **Analyze the Third Statement:**
- The statement claims that in Fasciola, flame cells take part in excretion.
- **Fasciola:** This is a type of flatworm, and it is true that flame cells are specialized excretory cells in flatworms.
- **Conclusion:** This statement is correct.

4. **Analyze the Fourth Statement:**
- The statement claims that earthworms are hermaphrodites and yet cross-fertilization takes place among them.
- **Earthworms:** This is true; earthworms have both male and female reproductive organs and can cross-fertilize with another earthworm.
- **Conclusion:** This statement is correct.

### Final Conclusion:
- The only incorrect statement is the first one regarding the excretion in prawns.

### Answer:
The incorrect statement is: "In cockroach and prawns, excretion of the waste material occurred through the Malpighian tubules."

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