Because A, G, C, and T appear in the DNA, these molecules are called DNA-bases; A, G, C, and U are called RNA-bases. Uracil and thymine are identical except that uracil lacks the 5' methyl group. Adenine and guanine belong to the double-ringed class of molecules called purines (abbreviated as R).
Definition of decalcomania. 1  1 : the art or process of transferring pictures and designs from specially prepared paper (as to glass) 2  2 : decal.
Substituting one set of discriminative stimuli for another (or, as a process, the stimulus control maintained after such a substitution).Transfer may be based on common properties of two sets of stimuli or on similar correlations of the two sets of stimuli with differential contingencies. formal verbal class in which a written stimulus occasions a corresponding written response. The correspondence is defined by the one-to-one relation of verbal units (e.g., letters or words) and not by sin-dlarity of visual features (e.g., a typed original may be transcribed in longhand).