All vertebrates are chordates but all chordates are not vertebrate.

Question

Given below are two statements:

one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): All vertebrates are chordates but all chordates are not vertebrate.

Reason (R): The members of subphylum vertebrata possess notochord during the embryonic period, the notochord is replaced by cartilaginous or bony vertebral column in adults. In the light of the above statements, choose the correct answer from the options given below:

1. A. Both (A) and (R) are true and (R) is the correct explanation of (A) (Correct answer)
2. B. Both (A) and (R) are true but (R) is not the correct explanation of (A)
3. C. (A) is true but (R) is false
4. D. (A) is false but (R) is true

Correct Answer

Option A — Both (A) and (R) are true and (R) is the correct explanation of (A)

Detailed Solution & Explanation

The correct answer is Both (A) and (R) are true and (R) is the correct explanation of (A).

Key Points

• Members of subphylum Vertebrata possess a notochord in the embryonic period, which is later replaced by a cartilaginous/bony vertebral column in adults — R is true.
• Because vertebrates are a subgroup of the phylum Chordata, all vertebrates are chordates but not all chordates are vertebrates — so R correctly explains A.