Question

Which one of the following class of phylum mollusca is correctly matched with its general characteristics?
Gastropoda - larvae are bilaterally symmetrical; but in adult, the twisting of viscera makes them lose this symmetry. some, like land snail and slug (a shell-less form), live on land.
Bivalvia - They are sedentary filter feeders.
Cephalopoda - They are at the apex of invertebrate evolution in terms of learned behaviour they exhibit. The eyes are image forming, same what similar to ours.
Pelecypoda - They have sensory tentacles and their foot is reduced into a tongue - shaped structure which helps them to burrow into sea floor.

Answer 1

1. The larvae of Gastropods is bilaterally symmetrical but adults lose their Symmetry due to torsion in the cell.

2. Bivalvia includes the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders.

3. Coleoidea subclass (cuttlefish, squid, and octopuses), are thought to be the most intelligent invertebrates and an important example of advanced cognitive evolution in animals. They have vertebrate-like eyes.

4. Pelecypoda buries themselves in sediment where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim.

So, the correct option is 'All of these'.