An important evolutionary transition that appeared for the first time in Echinoderms is:
| 1. | Bilateral symmetry | 2. | Radial symmetry |
| 3. | Tube within a tube plan | 4. | Endoskeleton |
A water vascular system is characteristically present in:
| 1. | Annelids | 2. | Porifers |
| 3. | Echinoderms | 4. | Cartilaginous fishes |
| 1. | They have bilateral symmetry as adults and radial symmetry as larvae. |
| 2. | They are triploblastic and coelomates. |
| 3. | They possess a well-developed excretory system. |
| 4. | They have an incomplete digestive system. |
| 1. | Sea Urchin | 2. | Sea lily |
| 3. | Brittle star | 4. | Brain coral |