a. Transversion is the substitution for a base of one chemical category by a base of other chemical category. In transversion, pyrimidine is replaced by a purine (from C to A, C to G, T to A, T to G) or a purine is replaced by a pyrimidine. (That is from A to C, A to T, G to C, G to T). The transversions that can be made with the codon CGG are AGG, GGG, CCG, CUG, CGC, and CGU.
b. The missense transversions are mutations in which one amino acid is replaced by a chemically different amino acid. This alters the structure and the function of the protein. The missense transversions are-
AGG—arginine, GGG---glycine, CCG---proline, CUG---leucine, CGC---arginine, CGU---arginine
In RNA, uracil replaces thymine.