The complementary base pairing of the DNA is the two strand of the DNA molecules have the complementary base pairs in the structure.
<u>Explanation:</u>
The DNA strands contain the nucleotide sequence which helps the strand to supply the information needed for the molecules to produce the partner in the DNA structure.
If the strands of the DNA molecules are separated then each sequence can be used as a pattern, so it can template to produce the complementary strands in the DNA easily.