Question

All vertebrates are chordates but all chordates are not vertebrates justify the statement

Answer 1

Because in vertebrates notochord is only present in embryonic stage and then it is replaced by bony vertebral column.

Answer 2

All vertebrates are chordates but all chordates are not vertebrates justify

Answer=>

The members of subphyLum vertebrate possess notochord during the embryonic period hence the notochord is replaced by a bony vertebral column in adults