Question

Difference between echinodermata and chordata on the basis of notochord.

Answer 1

chordates have presence of notochord at the dorsal surface usually.. in vertebrates ( lower taxa below chordates )notochord develops into vertebra

echinoderms don't have notochord... they have internal skeleton which Is made of calcified plates

Answer 2

Symmetry

Echinoderms and chordates have different types of symmetry, one of their most obvious differences. Chordates like humans have bilateral symmetry, which means you can divide them into a left and right half, and that they have a defined top, bottom, front and back. Echinoderms have radial symmetry, which means you can divide them in various cuts along the center and get equivalent shapes, and have only a defined top and bottom. It can help to visualize the difference if you consider that hotdogs in a bun have bilateral symmetry, while hamburgers have radial symmetry.

Nervous System

Echinoderms and chordates also have very different nervous systems. Echinoderms' nervous systems consist of a neural net without any kind of central point. Chordates have a central nervous system, called a notochord or a neural tube. In many chordates, the end of the notochord is enlarged to form a defined, centralized brain -- a feature no echinoderm has. This goes hand in hand with anteriorization, the formation of a head at the front of an animal. This allows chordates to concentrate their sensory structures in one area.