'''Uracil''' is one of the four bases in [[RNA]]. The others are [[adenine]], [[guanine]], and [[cytosine]]. Uracil replaces thymine, which is the fourth base in DNA. Like thymine, uracil always pairs with adenine. | '''Uracil''' is one of the four bases in [[RNA]]. The others are [[adenine]], [[guanine]], and [[cytosine]]. Uracil replaces thymine, which is the fourth base in DNA. Like thymine, uracil always pairs with adenine. |