In which of the following true coelom appeared for the first time in the course of evolution (a)Annelida (b)Chordata (c)Aschelminthes (d)Echinodermata
Option A A true coelom may be defined as a secondary body cavity, formed by the splitting of mesoderm during embryonic development and bounded on all sides by a definite coelomic epithelium or peritoneum. A true coelom was evolved for the first time in annelids.
