A DNA segment has base order AGC TTA TCG. Which copy exhibits a frameshift mutation through deletion?(1 point)

Responses

AGC TCG
AGC TCG

AGC TTA TAG
AGC TTA TAG

TTA TCG
TTA TCG

AGC TTT CG

1 answer

A frameshift mutation occurs when bases are added or deleted from the DNA sequence, leading to a shift in the reading frame of the genetic code.

The original DNA segment is: AGC TTA TCG.

Now, let's analyze each of the given responses:

  1. AGC TCG: This exhibits a deletion of one base (the second "T"), resulting in a shift in the reading frame.

  2. AGC TTA TAG: This is not a frameshift mutation, as it has simply replaced "TCG" with "TAG" (substitution), but the length is the same.

  3. TTA TCG: This has deleted the "AGC" at the start, which is still a deletion but does not represent a frameshift mutation starting from the first base.

  4. AGC TTT CG: This introduces a base pair change and a deletion, but it retains the overall length, which could mask a frameshift.

The best option that clearly indicates a frameshift mutation through deletion is:

AGC TCG.