Clams are a part of the Bivalvia class.
Clams belong to the bivalvia class and the veneridae family. They also belong to the Animalia kingdom and the Mollusca phylum.
If by biological you mean the phylogeny it's phylum mollusca, class bivalvia, subclass heterodonta
Bivalve mollusks
Oysters belong the the invertebrate group of mollusk.
Tigers belong to Class Mammalia.
Opossums belong to the class mammalia.
Sea fans belong to the class Anthozoa
A piranha belong to the Phylum Chordata, and the class Osteichthyes.
Echidnas belong to the Class Mammalia and Order Monotremata.
They belong to the class Mammalia ( mammals).
the priests belong to the upper class (1st class)
the priests belong to the upper class (1st class)