Refer to the figure. Which of the nucleotide substitutions in an mRNA strand would have the most harmful effect on the activity of the protein that it encodes?

Question

Refer to the figure.  Which of the nucleotide substitutions in an mRNA strand would have the most harmful effect on the activity of the protein that it encodes?

Quizplus · Accepted Answer

The substitution of GGA to UGA would result in a premature stop codon (UGA is a stop codon) and therefore result in a truncated protein that may be non-functional or have altered function. The other substitutions do result in changes to the amino acid sequence of the protein but they do not necessarily result in a stop codon and may not have as severe an impact on the activity of the protein.

Refer to the Figure