Torsion

Question

Torsion
A) Is found in mollusks that lack a radula
B) Is found in only the scaphopods
C) Is an important feature of gastropods
D) Refers to the spiral form of the shell

Accepted Answer

Torsion is a distinctive developmental process of gastropods, involving the rotation of the visceral mass, mantle, and shell 180 degrees with respect to the head and foot. This process gives many snails their asymmetrical body and allows the mantle cavity and anus to be positioned above the head.