Which base pairs with cytosine in DNA?

In the structure of DNA, cytosine pairs specifically with guanine through three hydrogen bonds. This complementary base pairing is a critical feature of the double helix structure, ensuring accurate replication and the proper transmission of genetic information. The specific size and shape of the nitrogenous bases are what enable this pairing; cytosine has a structure that allows it to bond effectively with guanine, maintaining the consistent distance between the two strands of DNA and contributing to the stability of the overall structure.

In contrast, adenine pairs with thymine, and uracil, while it pairs with adenine in RNA, does not apply to DNA. Thus, understanding the specific pairing is fundamental in grasping molecular biology and genetics.