A normal DNA sequence is 5′-GTA GCA TCA CCA-5′. If the DNA sequence mutated to 5′-GCA GCA TTC ACC A-3′, how would the peptide sequence be affected?
A) All amino acids downstream of the mutation would be misinserted.
B) The peptide would not be synthesized.
C) An Arg would replace an His.
D) A stop would replace a Trp.
E) No change would occur.

Question

Quizplus · Accepted Answer

The mutation in the DNA sequence changes a single nucleotide, causing a change from the codon for histidine (CAC) to the codon for glutamine (CAA). This means that all amino acids downstream of the mutation (in the resulting peptide sequence) would have a different amino acid inserted than in the original sequence, resulting in a potentially different protein with altered function.

A Normal DNA Sequence Is 5′-GTA GCA TCA CCA-5′