In which animal is the body divided into a head,muscular foot,and visceral hump?

The respiratory pigment haemocyanin is found in which of the following phyla?

Which invertebrate phylum exhibits unisexual or hermaphrodite conditions,external or internal fertilization,and direct or indirect development?

$Mytilus$ belongs to which class?

Which of the following serves as the excretory organ in $Dentalium$?

In which group of molluscs is torsion a very important event in the life history?