84. Which of the following descriptions regarding genetic code is NOT correct?
(A) The genetic code is degenerate, and many codes can specify a certain amino acid.
(B) The first two positions of a codon are more important, and mutation in the third position often does not change thesense of the codon.
(C) One codon consists of three bases.
(D) Missense mutation changes only one codon and sometimes does not cause phenotypic change.
(E) Frameshift mutations can be suppressed by a suppressor tRNA molecule.