<prompt> Maximum number of unusual base pairs are seen inrRNAtRNAmRNAsnRNA  <response>: The transfer RNA show extensive internal base pairing and acquire clover leaf like structures. They contain a significant propoion of unusual bases. These include dihydrouracil DHU pseudouridine Ps and hypoxanthine. Moreover, many bases are methylated. REFERENCE : DM.VASUDEVAN.TEXTBOOK SEVENTH EDITION ; PAGE NO : 596. 