<prompt> All of the following bases are present in DNA, EXCEPT:AdenineGuanineUracilThymine  <response>: DNA contains only four different bases: adenine A, guanine G, thymine T, and cytosine C. DNA exists as a double helix in which A is always paired with T, and G is always paired with C. RNA contains the ribonucleotides of adenine, guanine, and cytosine, it does not possess thymine. Instead of thymine, RNA contains the ribonucleotide of uracil. Ref: Weil P. 2011. Chapter 34. Nucleic Acid Structure Function. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell Eds, Harpers Illustrated Biochemistry, 29e. 