Question 9.
Answer in brief.
Write four distinguishing characters of phylum- Echinodermata.
Answer:
1. Calcareous spines are present on the body of these animals; hence they are called as echinoderms.
2. These animals are found only in ocean.
3. Their body is triploblastic, eucoelomate and it is radially symmetrical in adult stage. However, they show bilateral symmetry in larval stage.
4. They perform locomotion with the help of tube-feet. Tube feet are also useful for capturing the prey. Some animals are sedentary. Examples: Star fish, sea-urchin, brittle star, sea-cucumber, etc.
