Notochord and Vertebral Column — NEET Biology
✅ Asked in NEET 2022Assertion (A): All vertebrates are chordates but all chordates are not vertebrates. Reason (R): Notochord is replaced by vertebral column in adult vertebrates. Choose the correct option: NEET Year: NEET 2022
Assertion (A): All vertebrates are chordates but all chordates are not vertebrates. Reason (R): Notochord is replaced by vertebral column in adult vertebrates. Choose the correct option: NEET Year: NEET 2022
Answer & NCERT explanation
Correct answer: A — Both A and R are correct and R explains A
Both assertion and reason are correct, and reason explains assertion. All vertebrates have vertebral column (modified notochord) so are chordates, but not all chordates are vertebrates (urochordates and cephalochordates lack vertebrae). Reason correctly explains that notochord gets replaced by vertebral column in adult vertebrates, which is why vertebrates are a subset of chordates.
Read more NCERT concept on the PYQ
The members of subphylum Vertebrata possess notochord during the embryonic period. The notochord is replaced by a cartilaginous or bony vertebral column in the adult. Thus all vertebrates are chordates but all chordates are not vertebrates. Besides the basic chordate characters, vertebrates have a ventral muscular heart with two, three or four chambers, kidneys for excretion and osmoregulation and paired appendages which may be fins or limbs.
NTA tests whether students understand that vertebrates possess a notochord only during embryonic development, which is later replaced by a vertebral column (backbone) in adults. This is a key distinguishing feature of vertebrates within chordates. The common mistake is assuming all chordates have a notochord throughout life, or confusing the notochord with the vertebral column. Remember: notochord is temporary (embryonic), vertebral column is permanent (adult). Also critical for NEET: all vertebrates are chordates, but NOT all chordates are vertebrates—non-vertebrate chordates like amphioxus retain their notochord throughout life. This concept tests understanding of chordate evolution and vertebrate classification.
What does NCERT say about members subphylum Vertebrata possess?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.