Compounds that contain a nitrogenous base, a sugar, and a phosphate group are called (a) _____. Two purines found in DNA are (b) _____ and _____ A pyrimidine found in all DNA but in only some RNA is (c) _____. In DNA, the base pair (d) _____-_____ is held together by three hydrogen bonds; the base pair (e) _____-_____ has only two such bonds.