Which base pairs with Thymine in a DNA sequence?

In a DNA sequence, Thymine pairs exclusively with Adenine through two hydrogen bonds. This pairing is a fundamental aspect of the DNA structure, where nitrogenous bases adhere to specific pairing rules known as complementary base pairing. Thymine, which is a pyrimidine, pairs with Adenine, a purine, ensuring the DNA double helix maintains its uniform structure.

Understanding this pairing is crucial, as it plays a vital role in processes such as DNA replication and transcription. Thymine does not pair with Cytosine, Guanine, or Uracil under standard DNA conditions. Cytosine pairs with Guanine instead, which is another complementary pair in the DNA structure. Uracil is found in RNA, where it replaces Thymine, but it does not participate in base pairing in DNA itself. Thus, the correct answer is that Thymine pairs with Adenine in a DNA sequence.