Give diagnostic characters of phylum chordata.

Explanation

The chordates have four diagnostic characters. These are as follows:
(i) Notochord : It is a solid, elastic, flexible rod present between alimentary canal and nerve cord.
(ii) Dorsal hollow nerve cord: The nerve cord develops in a chordates embryo, located above the notochord.
(iii) Pharyngeal slits : These are paired openings. These remain functional throughout the life in fish and in some amphibians.
(iv) Post anal tail : A post-anal tail is present in most of chordates at least in the embryonic stage.