Eduprobe
Question:
Under which of the following conditions will there be no change in the reading frame of the following mRNA?
Insertion of G at 5th position
Insertion of A and G at 4th and 5th positions respectively
Deletion of G from 5th position
Deletion of GGU from 7th, 8th and 9th positions
Solution:
Correct option is D. Deletion of GGU from 7th, 8th and 9th positions. The reading frame is determined by the sequence of codons (three nucleotide units) in the mRNA. Insertion or deletion of a nucleotide that is not a multiple of three will shift the reading frame, resulting in a different translation. Only the deletion of a codon (three nucleotides), like GGU, maintains the reading frame.