Two synonymous codons are specific for histidine. If the last base of one of these codons was changed to a different nucleotide, what could be the outcome?
A) There would be a frameshift mutation.
B) The codon would specify an amino acid other than histidine.
C) Because of degeneracy, the codon would still specify for histidine.
D) The codon could still be specific for histidine, or it could be specific for a different amino acid.
E) It would result in a 'nonsense' codon that did not specify any amino acid.

Question

Quizplus · Accepted Answer

The genetic code is degenerate, meaning that multiple codons can code for the same amino acid. For histidine, changing the last base of one of its codons could either result in another codon for histidine (due to the redundancy in the genetic code) or a codon for a different amino acid, depending on the specific base change. This does not necessarily lead to a frameshift mutation, a nonsense codon, or an amino acid other than histidine in every case.

Two Synonymous Codons Are Specific for Histidine