Under which of the following conditions there will be no change in the reading frame of following mRNA?

5' AACAGCGGUGCUAUU 3'

detailed solution

Correct option is A

Genetic code is triplet.If we delete GGU from 7th , 8th and 9th position then the entire codon will be deleted. Hence there will not be any change in the reading frame.Insertion of a single nucleotide alter the reading frame and will lead to frame shift mutationDeletion of a single nucleotide alter the reading frame and will lead to frame shift mutation.Addition of A and G will also alter the reading framing as genetic code is triplet.