Q. All vertebrates are chordates but all chordates are not vertebrates, because:
A) Vertebrates lack a notochord at all stages
B) Chordates lack a dorsal nerve cord
C) Vertebrates are non-chordates
D) In Urochordata and Cephalochordata the notochord is not replaced by a vertebral column
Explanation
In vertebrates the embryonic notochord is replaced by a cartilaginous or bony vertebral column in the adult. Protochordates do not form a vertebral column.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.