UAC to UAG-
**Core Concept**
The question is testing the student's knowledge of the codon translation process in genetics. Specifically, it is asking about the translation of a particular codon from its universal amino acid code (UAC) to its corresponding amino acid abbreviation (UAG). This process involves the decoding of messenger RNA (mRNA) codons into specific amino acids during protein synthesis.
**Why the Correct Answer is Right**
The correct answer involves understanding the genetic code, which is a set of rules that translate sequences of nucleotides into amino acid sequences. The codon UAC corresponds to the amino acid tyrosine, while UAG is a stop codon that signals the termination of protein synthesis. However, the correct answer is not about the direct translation of UAC to tyrosine, but rather about the correction of the codon UAG to its corresponding amino acid abbreviation. This requires knowledge of the genetic code, particularly the wobble hypothesis, which allows for some flexibility in the base pairing of the third nucleotide in the codon.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately reflect the translation of the codon UAG. The correct translation of UAG is not a specific amino acid, but rather a stop signal.
**Option B:** This option is incorrect because it is not a valid amino acid abbreviation. The correct amino acid abbreviation for the codon UAC is tyrosine, not the option listed.
**Option C:** This option is incorrect because it does not accurately reflect the translation of the codon UAG. The correct translation of UAG is not the amino acid listed, but rather a stop signal.
**Clinical Pearl / High-Yield Fact**
The genetic code is almost universal, but there are some exceptions, particularly in mitochondria. It's essential to remember the genetic code and its exceptions to accurately diagnose and treat genetic disorders.
**Correct Answer: C. UAG is a stop codon.**