In which segments is the clitellum present in an earthworm?

Chloragogen cells are responsible for:

Which of the following animal's sensory system does not have eyes but does possess light and touch sensitive organs (receptor cells) to distinguish the light intensities and to feel the vibrations in the ground?

Which of the following is a characteristic of the dorsal blood vessel in an earthworm?

The nephridiopore is the opening of $............$.

The intestinal excretory organs (septal nephridia) of $Pheretima$ have a function of: