Q. In the DNA molecules
A) There are two strands which run antiparallel-one in 5'→3' direction and other in 3'→5'
B) The total amount of purine nucleotides and pyrimidine nucleotides is not always equal
C) There are two strands which run parallel in the 5'→3' direction
D) The proportion of Adenine in relation to thymine varies with the organism
Explanation
[Solution from source] The two polynucleotide chains of the double helix run antiparallel, one 5'→3' and the other 3'→5'. By Chargaff's rule, purines always equal pyrimidines and A always equals T in double-stranded DNA, so those options are false. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.