<prompt> Which is seen in RNA but not seen in DNA?AdenosineGuanineUracilThymine  <response>: In the Watson-Crick base pairing, adenine A forms a base pair with thymine T, as does guanine G with cytosine C in DNA.In RNA, thymine is replaced by uracil U.Alternate hydrogen bonding patterns also occur -- paicularly in RNA -- giving rise to complex and functional teiary structures. 