Question

Which of the following is correct about the earthworm Pheretima?

• A. Fertilisation of eggs occurs inside the body
• B. The typhlosole greatly increases the effective absorption area of the digested food in the intestine
• C. The S- shaped setae embedded in the integument are the defensive weapons used against the enemies
• D. It has a long dorsal tubular heart

Answer 1

The correct option is B The typhlosole greatly increases the effective absorption area of the digested food in the intestine

Typhlosole is an internal fold of the dorsal wall in earthworm. Typhlosole is present from the ${26}^{th}$ segment till the end almost. The folded portion increases the surface area for the absorption of food in the intestine of earthworm.
Setae are the ‘S’-shaped structures present in the epidermal pits of the earthworm. The primary role of setae is locomotion.
Fertilisation occurs inside the cocoon and not inside the body.
Earthworms do not have a true heart and are not tubular. They have five pairs of aortic arches which pumps blood throughout the body.