What best describes the relationship between the two DNA strands at the replication fork?

The relationship between the two DNA strands at the replication fork is best described as complementary. In the DNA double helix, each strand serves as a template for the synthesis of a new strand during replication. The complementary nature of DNA is due to the specific base-pairing rules: adenine pairs with thymine, and guanine pairs with cytosine.

As DNA replicates, enzymes like DNA polymerase synthesize new strands by adding nucleotides that are complementary to the bases on the template strand. This means that if the template strand has an adenine, the newly synthesized strand will incorporate a thymine nucleotide, and so forth with the other base pairs.

This relationship is crucial for maintaining the genetic information through generations, as it allows for accurate replication of the DNA sequence. The fact that the strands are complementary ensures that the genetic code can be preserved and accurately passed on.