Identify the organisms with following characters:
Soft bodied, unsegmented, muscular head, foot and visceral mass, mantle, a calcareous shell, sexual reproduction

Q.

In phylum ______, the animals have a soft, unsegmented body, with a hard, calcareous shell to protect the soft body.

Q. The absence of head, unsegmented body, and endoskeleton of dermal calcareous plate are the characters of

Q. Absence of head, unsegmented body and endoskeleton of dermal calcarous plate are the characters of

Q. Assertion :In gastropods, due to torsion mantle cavity is placed anteriorly behind and above the head.
Reason: During larval stage, visceral mass, shell and mantle cavity are twisted upto 180 counter clockwise with respect to the head and foot.