In Wobble hypothesis, true statement regarding variation is

Wobble Allows Some tRNAs to Recognize More than One Codon: When several different codons specify one amino acid, the difference between them usually lies at the third base position (at the 3' end). For example, alanine is coded by the triplets GCU, GCC, GCA, and GCG. The codons for most amino acids can be symbolized by The first two letters of each codon are the primary determinants of specificity Transfer RNAs base-pair with mRNA codons at a three-base sequence on the tRNA called the anticodon. The first base of the codon in mRNA (read in the 5'-3'direction) pairs with the third base of the anticodon If the anticodon triplet of a tRNA recognized only one codon triplet through Watson-Crick basepairing at all three positions, cells would have a different tRNA for each amino acid codon. This is not the case, however, because the anticodons in some tRNAs include the nucleotide inosinate (designated I), which contains the uncommon base hypoxanthine. Inosinate can form hydrogen bonds with three different nucleotides (U, C, and A), although these pairings are much weaker than the hydrogen bonds of Watson-Crick base pairs. Hence the third base of such codons (and the first base of their corresponding anticodons) "wobbles." Crick proposed a set of four relationships called the wobble hypothesis: