Question

One very special feature in the earthworm (Pheretima) is that

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

Answer 1

Answer: (C)

A. The ova (eggs) are fertilised by the sperm cells within the cocoon which are deposited in the soil and not inside the body.

B. The characteristic feature of the intestine between 26-35 segments is the presence of internal median fold of dorsal wall called typhlosole. This increases the effective area of absorption in the intestine.

C. S-shaped' setae embedded in the epidermal pits in the middle of each segment serve the principal role of locomotion and not defence.

D. Earthworm possesses a segmented; not a long dorsal tubular heart.

So, the correct option is 'The typhlosole greatly increases the effective absorption area of the digested food in the intestine'.