Frameshift mutation does not effect complete amino acid sequence if it occurs in multiple of

**Core Concept**
A frameshift mutation is a type of genetic mutation caused by insertions or deletions of nucleotides in a DNA sequence, leading to an entirely different translation of the genetic code from the original. This occurs because the reading frame of the genetic code is shifted. The **genetic code** is read in sequences of three nucleotides at a time, known as codons, which specify particular amino acids.

**Why the Correct Answer is Right**
The correct answer is related to how the genetic code is read and translated into amino acid sequences. If a frameshift mutation occurs in a multiple of three nucleotides, it means that the number of nucleotides inserted or deleted is a multiple of the codon length (three). As a result, the reading frame after the mutation remains the same as before the mutation, leading to the correct translation of the genetic code into amino acid sequences after the point of mutation.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because a frameshift mutation occurring in a single nucleotide would shift the reading frame, altering the amino acid sequence.
**Option B:** This option is incorrect because two nucleotides would also shift the reading frame, although by a different amount than a single nucleotide insertion or deletion.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that frameshift mutations can lead to completely nonfunctional proteins or proteins with entirely different functions, depending on where in the gene the mutation occurs. Understanding the impact of frameshift mutations is crucial in genetics and molecular biology, especially in the context of genetic diseases.

**Correct Answer:** Correct Answer: C. three.