Q. Assertion: In a DNA helix, purines are placed opposite to pyrimidines. Reason: The two strands of DNA maintain uniform distance between them.
A) Both assertion and reason are true and reason is the correct explanation of assertion.
B) Both assertion and reason are true but reason is not correct explanation of assertion.
C) Assertion is true, but reason is false.
D) Both assertion and reason are false.
Explanation
In a DNA double helix, a base pair is formed between a purine and pyrimidine and these are linked together through specific hydrogen bonding. Thus, the specific pattern of pairing among these nitrogenous pairs generates uniform distance between the two strands of DNA helix.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.