When the DNA sequence of the gene that codes for the peptide hormone insulin is compared in two mammals (e.g., humans and rats), most of the sequence differences are synonymous mutations. These far outnumber sequence differences that result in amino acid substitutions. Why might this be?
A)Mutations are random with respect to an organism's needs.
B)Amino acid substitutions often result in proteins that have lost or compromised function and, therefore, are selected against.
C)A DNA sequence is more likely to mutate if the change does not alter the amino acid sequence.
D)Most amino acid substitutions result in a beneficial phenotype that improves fitness and results in a greater number of offspring.
E)Synonymous mutations occur in noncoding DNA sequences.

Question

Quizplus · Accepted Answer

Amino acid substitutions often result in proteins that have lost or compromised function and, therefore, are selected against. This means that most of the changes that survive natural selection are synonymous mutations that do not change the amino acid sequence of the protein.

When the DNA Sequence of the Gene That Codes for the Peptide