Which nitrogenous base pairs with adenine in DNA?

In DNA, adenine pairs with thymine through the formation of two hydrogen bonds. This pairing is a fundamental aspect of the DNA double helix structure, where the specific base pairing contributes to the stability and fidelity of the genetic information. Thymine is unique to DNA and complements adenine, ensuring that the sequences of nucleotides can be accurately replicated during cell division.

The other bases mentioned, such as cytosine and guanine, do not pair with adenine in DNA. Instead, cytosine pairs with guanine through three hydrogen bonds. Uracil is a nitrogenous base found in RNA, where it pairs with adenine but does not occur in DNA. This distinction is critical for understanding the structural and functional differences between DNA and RNA.