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.
[deâ³kus-saÂ´shun] a crossing over; the intercrossing of fellow parts or structures in the form of an X. decussation of pyramids the anterior part of the lower medulla oblongata in which most of the fibers of each pyramid intersect as they cross the midline and descend as the lateral corticospinal tracts.