Q. One very special feature in the earthworm Pheretima is that
A) It has a long dorsal tubular heart
B) Fertilisation of eggs occurs inside the body
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
Explanation
[Solution from source] In Pheretima, the intestine has an internal median fold called the typhlosole, from the 26th segment onward, which greatly increases the absorptive area. The earthworm has no long tubular heart, fertilisation happens in the cocoon outside the body, and the setae help in locomotion, not defence. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.