Given below are two statements: one is labelled as Assertion and the other is labelled as Reason. Assertion: Cephalochordates, such as Branchiostoma , are chordates but are not classified under the subphylum Vertebrata. Reason: In cephalochordates, the notochord is persistent throughout life and is never replaced by a cartilaginous or bony vertebral column. In the light of the above statements, choose the most approp

Step-by-step solution

Cephalochordates, such as Branchiostoma , belong to the phylum Chordata because they possess a notochord, a dorsal hollow nerve cord, and pharyngeal gill slits. They are not classified under the subphylum Vertebrata because their notochord persists throughout their life and extends from the head to the tail region. In vertebrates, the notochord is present only during the embryonic period and is later replaced by a cartilaginous or bony vertebral column in the adult. Thus, the Assertion is correct, and the Reason is