1 Set of hunches. 2  If a theory is a set of hunches, it means we arenât yet sure we have the answer. 3  Theories always involve an element of speculation or conjecture. 4  A theory is not just one inspired thought or an isolated idea.  A theory offers some sort of explanation.
Uracil is paired with thymine in RNA and it is paired with Adenine in DNA. In DNA transcription (from DNA to RNA), uracil pairs with adenine. in regular DNA replication adenine pairs with thymine.
Therefore it is believed that actually thymine is a âprotectedâ form of uracil in DNA, that is simply methylated and does not get cut out. This enzyme does not do the same to RNA, so there was apparently no need for uracil to be replaced by thymine in the RNA.