Sand dollars , heart urchins and sea urchins are present in which of the following class ?

Sea urchin and heart urchin are present in

Sea urchin and heart urchin are present in

Food of sea urchins is

Shells of sea urchin and star fish is made up of

(a) Sand dollars, sea cucumbers and sea lilies are representatives of which phylum? What kindof symmetry the adult representatives of this phylum have ? Also mention what is specific about their body cavity ? (b) Name the organs of locomotion in these organisms.

Starfish, brittle star, sea urchin, crab.

Heart Urchin belongs to class

Heart Urchin belongs to class

Heart Urchin belongs to class