Ex.1 which of the following statements regarding mutation rates is correct? a) mutation rates are independent of gene size. b) mutation rates for all genes of an organism are approximately the same. c) mutation rates are independent of exposure to external agents such as uv radiation. d) average mutation rates vary among taxonomic groups. practice problem 64 the amino acid changes noted in parts a-c are the result of changes in dna sequence. for each of these amino acid changes, evaluate whether a single base change in the given codons could account for the change in the amino acid. part a for which codon(s) could a single base change account for this amino acid change? lysine to asparagine select all that apply. uuu aag aaa none of these codons part b for which codon(s) could a single base change account for this amino acid change? alanine to phenylalanine select all that apply. gcg gcu gcc gca none of these codons part c for which codon(s) could a single base change account for this amino acid change? leucine to glutamine select all that apply. cuc uug uua cug cuu cua none of these codons