What connects the components of DNA strands in pairs?

Hydrogen bonds are crucial in connecting the complementary bases of DNA strands, forming base pairs. In a DNA molecule, the two strands are held together by these hydrogen bonds between adenine and thymine, as well as between guanine and cytosine. This bonding is essential for maintaining the double helical structure of DNA, ensuring stability while allowing the strands to separate during processes like replication and transcription.

The other types of bonds listed do play significant roles in the structure of nucleic acids, but not in the pairing of bases. For instance, phosphodiester links refer to the connections between the sugar and phosphate groups of the DNA backbone, forming the structural framework of each single strand. Covalent bonds are present within the backbone of DNA, linking the sugar and phosphate components, but they do not involve the pairing of the bases across the two strands. Peptide bonds are specific to proteins, linking amino acids together, and are not involved in the structure of DNA at all.