all vertebrates are chordates but all chordates are not vertebrates...explain in detail....3 marks...

Chordates is one of the phylum of kingdom Animalia whose further sub phyla is Vertebrates, urochordate & cephalochordates. All the organism  in phylum chordates are characterized by presence of notochord and in sub phylum, this feature gets little more specific- Vertebrates include organisms having notochord in their embryonic stages. So we can say, all vertebrates are chordates as they have notochord but all chordates are not vertebrates because other sub phyla of chordates like cephalochordates -have notochord from head to tail region throughout their life.