Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the correct answer from the options given below:
- (A) is true but (R) is false
- (A) is false but (R) is true
- Both (A) and (R) are true and (R) is the correct explanation of (A)
- Both (A) and (R) are true but (R) is not the correct explanation of (A)
Answer
(3) Both (A) and (R) are true and (R) is the correct explanation of (A)
Solution
Members of subphylum Vertebrata possess a notochord during the embryonic period, which is replaced by a cartilaginous or bony vertebral column in the adult.
So every vertebrate is a chordate, but chordates of Urochordata and Cephalochordata have no vertebral column; hence all chordates are not vertebrates.
Both statements are true and R explains A.
Answer: (3)