Question

Pelecypoda are also called as
A.Bivalvia
B.Lamellibranchia
C. Both A & B
D.None of the above

Answer 1

Hint:Numerous freshwater and marine molluscs, including clams, mussels, oysters, and scallops, have a shell consisting of two hinged valves linked by a ligament.

Complete Answer:
Bivalvia, referred to as the Lamellibranchiata and Pelecypoda in previous centuries is a genus of molluscs of marine and freshwater that have laterally compressed bodies enclosed by a shell composed of two hinged parts. As a group, bivalves have no head, and some normal molluscular organs such as the radula and the odontophore are absent. They include clams, oysters, cockles, mussels, scallops, and a number of other saltwater families, as well as many freshwater families. Filter feeders are the majority. Ctenidia, specialised organs for feeding and breathing, have grown into gills. The majority of bivalves are submerged in soil, where they are relatively protected from predation. Others lie or stick themselves to rocks or other rough surfaces on the seafloor. Some bivalves can float, such as scallops and file shells. Within these substances, the shipworms bore into wood, clay, or stone and live.A bivalve's shell is composed of calcium carbonate and consists of two parts called valves, typically identical. These are connected together by a flexible ligament along one edge (the hinge line) that forms the hinge, typically in combination with interlocking "teeth" on each of the valves. Without the two halves detaching, this structure allows the shell to be opened and closed. The shell, with the hinge lying in the sagittal plane, is usually bilaterally symmetrical. Adult bivalve shell sizes range in length from fractions of a millimetre to over a metre, but most species do not exceed 10 cm (4 in).

Hence the correct answer is option ‘C’.

Note: Areolar connective tissue locks organs in place and connects other underlying tissues to epithelial tissue. For surrounding tissues, it often acts as a source of water and salts. Nearly all cells get their nutrients from the isolar connective tissue and release their waste into it.