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

The term 'Cephalopoda' refers to a class of animals in which .........

In which of the following organisms is the foot displaced to the neighborhood of the mouth and divided into arms?

The mollusc which is considered to be a living fossil and also shows characters of annelids like nephridia and internal segmentation is

What is the function of the radula?

In $Mollusca$, the feather-like gills are located in the: