Question

Which of the following is the character of Pila but not of Unio?

• A. Triploblastic
• B. Presence of kidney
• C. Coelomate
• D. During development it undergoes torsion

Answer 1

The correct option is D During development it undergoes torsion

Pila belongs to the gastropod class of Mollusca. These class members have a unique process which takes place known as Torsion in which rotation of the visceral mass to 180 degrees with respect to the head and foot. As Unio does not belong to this class this process is absent.

So the correct option is 'During development it undergoes torsion'