Answer:
Option A, In DNA, each base pairs up with only one other base.
Explanation:
DNA is made up of two complementary nucleotide (also referred to as base pairs). It is the purine which associates with the pyrimidine group.
The four bases in DNA are
• adenine (A) - a purine
• cytosine(C) - a pyrimidine
• guanine (G) - a purine
• thymine (T) - a pyrimidine
Adenine is complementary to thymine and cytosine is complementary to guanine
. Thus, Adenine forms complementary pair with thymine and cytosine forms complementary pair with guanine.
Hence, option A is correct.