Question

Under which of the following conditions will there be no change in the reading frame of the following mRNA - ​​5’AACAGCGGUGCUAUU3’?

• A. Insertion of G at 5th position
• B. Deletion of G from 5th position
• C. Insertion of A and G at 4th and 5th positions respectively
• D. Deletion of GGU from 7th, 8th and 9th positions

Answer 1

The correct option is D

Deletion of GGU from 7th, 8th and 9th positions

The correct option is D.

Explanation of the correct option:

1. The messenger RNA, or mRNA, is a single-stranded frame of an RNA molecule that matches a certain DNA segment's genetic sequence.
2. When the DNA duplex is created during transcription, this sequence of mRNA is created.
3. The reading frame of the mRNA sequence is unaffected by the deletion of GGU from positions 7, 8, and 9 in the provided sequence of the mRNA strand.

Explanation of the incorrect options:

Option A:

1. Any base pair inserted into the mRNA strand can be arranged incorrectly in the mRNA sequence, causing a mutation.

Option B:

1. The mutation caused by the codon change in the mRNA sequence will damage the protein sequence.
2. Any base pair deletion can cause mRNA sequence rearrangement leading to mutation.

Option C:

1. The mutation caused by the codon change in the mRNA sequence will damage the protein sequence by resulting in an altered protein product, which may or may not be functional.
2. Any base pair insertion can lead to either a nonfunctional or truncated version of a protein.

Final answer: There will be no change in the reading frame of the following mRNA - ​​5’AACAGCGGUGCUAUU3’ if deletion of GGU from the 7th, 8th, and 9th positions occurs.