Which Mollusc Clade Includes Members That Undergo Embryonic Torsion

Question

Which mollusc clade includes members that undergo embryonic torsion?
A)chitons
B)bivalves
C)gastropods
D)cephalopods

Accepted Answer

Gastropods are the only mollusc clade that includes members that undergo embryonic torsion, which is a twisting of the body during development that results in the anus and mantle cavity being placed above the head. This unique characteristic is only found in gastropods, such as snails, slugs, and whelks.