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 excertion
D. Earthworm are hermaphrodites and yet cross fertilization take place among them

Answer

To determine which statement is incorrect, let's analyze each option one by one.

1. **Statement 1**: "In cockroaches and prones, excretion of waste material occurs through malpighian tubules."
- **Analysis**: This statement is partially true. In cockroaches, excretion does occur through malpighian tubules. However, in prawns (which are crustaceans), excretion occurs through green glands, not malpighian tubules. Therefore, this statement is incorrect.

2. **Statement 2**: "In tino forts, locomotion is mediated by completes."
- **Analysis**: This statement is true. In the phylum Cnidaria (which includes tinofors), locomotion is indeed mediated by structures called completes (or cilia).

3. **Statement 3**: "In fasciola, flame cells take part in excretion."
- **Analysis**: This statement is true. Fasciola, also known as liver fluke, has flame cells that are involved in excretion.

4. **Statement 4**: "Earthworms are hermaphrodites and yet cross-fertilization takes place among them."
- **Analysis**: This statement is true. Earthworms possess both male and female reproductive organs (hermaphrodites), but they still engage in cross-fertilization. This occurs because the male reproductive organs mature before the female organs.

**Conclusion**: The incorrect statement is the first one regarding cockroaches and prawns.