Nucleotide bases are adenine, thymine, guanine, cytosine, and uracil (unique in RNA). Adenine is always paired with thymine or uracil and guanine is always paired with cytosine. In transcription, a single strand of DNA is transcribed to RNA with the respective base pairing except RNA does not contain thymine instead it uses uracil.
For example:
AAACGTTACCGACATTAC
Transcribing the following DNA sequence to RNA will yield:
UUUGCAAUGGCUGUAAUG
