Question
“All vertebrates are chordates but all chordates are not vertebrates”. Justify the statement.
Solution
Chordates are those animals which have a notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits. Chordates are sub classified into four other groups of which vertebrate is one subphyla.
However, Vertebrates are characterized by the presence of the notochord in the embryonic stage, which gets replaced by a cartilaginous or bony vertebral column in adults.
Since the notochord is not replaced by the vertebral column in all the chordates, thus, it can be said that all vertebrates are chordates but all chordates are not vertebrates.
