Codons that specify the same amino acid often differ in the :

1. Codons that specify the same amino acid often differ in the :

A) first base
B) second base
C) first and second base
D) third base

... Answer is C)  first and second base

Most amino acids in proteins are specified by more than one codon (i.e. the genetic code is degenerate). Recognition of these codons often occurs using different tRNAs (with corresponding anticodons to these codons) that bind the same amino acid (isoaccepting tRNAs). In addition, codons that specify the same amino acid (synonyms) often differ only in the third base, the wobble position, where base pairing with the anticodon may be less stringent than for the first two positions of the codon, allowing one tRNA to recognize more than one codon.