Silent mutations occurs because codon is :
**Core Concept**
Silent mutations occur when a point mutation in DNA results in no change to the amino acid sequence of the protein being synthesized. This phenomenon is a result of the degeneracy of the genetic code, where more than one codon can code for the same amino acid.
**Why the Correct Answer is Right**
Silent mutations occur due to the redundancy of the genetic code. For example, the codon GAA codes for glutamic acid, while GAG also codes for glutamic acid. If a mutation changes the codon from GAA to GAG, the resulting amino acid sequence remains unchanged. This is because the genetic code is degenerate, allowing multiple codons to specify the same amino acid.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the explanation of silent mutations.
**Option B:** This option does not accurately describe the mechanism of silent mutations.
**Option C:** This option is incorrect because silent mutations do not occur due to the presence of a stop codon.
**Clinical Pearl / High-Yield Fact**
The genetic code is degenerate, meaning that more than one codon can code for the same amino acid. This redundancy is a result of the evolution of the genetic code and allows for silent mutations to occur.
**Correct Answer: D. The degeneracy of the genetic code.**