'''Adenine''' is one of the four bases in [[DNA]] that make up the letters ATGC, adenine is the "A". The others are [[guanine]], [[cytosine]], and [[thymine]]. Adenine always pairs with thymine.
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DNA has four bases: [[adenine]], [[thymine]], [[guanine]], and [[cytosine]] (ATGC). Adenine always pairs with thymine (AT), and guanine always pairs with cytosine (GC).