Question

Write four distinguishing characters of phylum- Echinodermata. <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> [Textbook Question No.5b Pg no. 75]

Answer 1

• Echinoderms are invertebrates inhabiting marine life.
• They are characterized by radial symmetry and have mostly five arms (Starfish), bilateral symmetry where body is divided in two equal halves (sea cucumbers), and spherical (Sea urchin).
• Their body shows presence of ossicles which are small calcareuos spicules that are completely embedded within the dermis of the body wall.
• The echinoderms use a hydraulic system known as the water vascular system for transportation of food, waste and respiration.
• Echinoderms show locomotion using tube feet which are a small, active, tubular projections, lying on the oral face of the organism.