Here's why:

* Hydrogen bonds are relatively weak bonds formed between a hydrogen atom covalently linked to a highly electronegative atom (like oxygen or nitrogen) and an electron pair in the adjacent atom.

* In DNA, the nitrogenous bases form hydrogen bonds with each other. Adenine (A) forms two hydrogen bonds with thymine (T), while guanine (G) forms three hydrogen bonds with cytosine (C).

* These hydrogen bonds are crucial for the stability of the double helix structure of DNA. They hold the two strands of DNA together, allowing for the information to be replicated accurately.

It's important to note that the bonds between the sugar-phosphate backbone of DNA are phosphodiester bonds. These bonds are much stronger than hydrogen bonds and are responsible for linking the nucleotides together to form the DNA chain.