What is the interaction between the two chains of DNA?

The interaction between the two chains of DNA is primarily characterized by hydrogen bonds between the base pairs. In the double helix structure of DNA, the two strands are complementary, with specific base pairing occurring: adenine pairs with thymine, and cytosine pairs with guanine. These base pairs are held together by hydrogen bonds, which are relatively weak compared to covalent bonds but are crucial for maintaining the structure of the DNA helix.

The presence of these hydrogen bonds allows the DNA strands to separate during processes like replication and transcription while still holding the two strands together under physiological conditions. This pairing mechanism contributes to the fidelity of genetic information transmission, allowing for accurate replication and expression of genes.

The other options do not accurately describe the primary interactions between the DNA strands. Covalent bonds are indeed present along the backbone of each individual DNA strand, but they do not account for the interaction between the two strands themselves. Ionic bonds and dipole interactions are not significant contributors to the stability and structural integrity of the DNA double helix.