What type of bonds hold the two strands of DNA together?

The correct answer is hydrogen bonds, which play a crucial role in the structure of DNA. In the double helix formation, the two strands of DNA are held together by pairs of nitrogenous bases. Each base pair—adenine with thymine, and cytosine with guanine—forms hydrogen bonds between them. These bonds are relatively weak, allowing the two strands to separate easily during processes such as replication and transcription, which is vital for DNA’s function in the cell.

Hydrogen bonds provide a balance between stability and flexibility in the DNA structure. While the covalent bonds form the backbone of each DNA strand by linking the sugar and phosphate groups, it is the hydrogen bonds between the base pairs that hold the two strands together. This unique combination allows DNA to maintain its double-helix structure while still being accessible for necessary cellular processes.