Question 14.
Give scientific reasons.
All vertebrates are chordates but all chordates are not vertebrates.
Answer:
Chordates have a supporting notochord in the body. In sub-phylum Vertebrata, the notochord present in embryos gets replaced by a cartilaginous or bony vertebral column in adults. But in cephelochordates, notochord persists throughout life as such and in urochordates, notochord is present only in larval stages and absent in adults. Thus, it can be said that all vertebrates are chordates but all chordates are not vertebrates.
