Question

In the DNA molecule ______.

Options

• the proportion of adenine in relation to thymine varies with the organism

• there are two strands which run antiparallel—one in 5' → 3' direction and other in 3' → 5'

• the total amount of purine nucleotides and pyrimidine nucleotide is not always equal

• there are two strands which run parallel in the 5' → 3' direction

Answer 1

In the DNA molecule there are two strands which run antiparallel—one in 5' → 3' direction and other in 3' → 5'.

Explanation:

The two DNA strands are antiparallel, with opposite 5′→3′ orientations. A equals T and total purines equal total pyrimidines, so the other statements are incorrect.