The $Bipinnaria$ larva is found in:

Assertion : Ambulacral system plays a major role in locomotion of echinoderm.
Reason : Hydraulic pressure of fluid and contraction of muscle of tube feet make possible movement of echinoderm.

Echinoderms are headless,brainless,and heartless. Yet,they are placed at the top of invertebrates because of the presence of:

Tube-feet are the locomotory organs of

An animal phylum having radially symmetrical adults but bilateral symmetrical larvae is

Identify the phylum in which adults exhibit radial symmetry and larva exhibit bilateral symmetry.