In phylum echinodermata, the adult echinoderms are ______A__________ but larvae are _______B______ .
A. A radially symmetrical; B bilaterally symmetrical
B. A bilaterally symmetrical; B radially symmetrical
C. A bilaterally symmetrical; B asymmetrical
D. A metamerically segmented; B asymmetrical
Correct Answer : A.
Echinoderms are a phylum of marine animals. The adults are recognizable by their (usually five-point) radial symmetry, whereas the larvae are bilaterally symmetrical. For example starfish, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or stone lilies.