Which one of the following triplet codes, is correctly matched with its specificity for an amino acid in protein synthesis or as 'start' or 'stop' codon ?

Options

A. UCG- Start
B. UUU-Stop
C. UGU-Leucine
D. UAC-Tyrosine

Answer

To solve the question regarding which triplet code is correctly matched with its specificity for an amino acid in protein synthesis or as a 'start' or 'stop' codon, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks us to identify the triplet code that is correctly matched with its corresponding amino acid or function (start/stop codon).

2. **Review the Options**: We have four options to evaluate:
- Option A: U, C, G - Start codon
- Option B: U, U, U - Stop codon
- Option C: U, G, U - Cysteine
- Option D: U, A, C - Tyrosine

3. **Analyze Each Option**:
- **Option A (U, C, G)**: This is incorrect. The start codon is A, U, G (AUG), not UCG. UCG codes for serine.
- **Option B (U, U, U)**: This is incorrect. UUU codes for phenylalanine, not a stop codon. The actual stop codons are UAA, UAG, and UGA.
- **Option C (U, G, U)**: This is incorrect. UGU codes for cysteine, but it is not a start or stop codon.
- **Option D (U, A, C)**: This is correct. UAC codes for tyrosine, which is an amino acid.

4. **Conclusion**: After analyzing all options, the correct match is found in Option D, where UAC corresponds to the amino acid tyrosine.

### Final Answer:
The correct answer is **Option D: UAC codes for Tyrosine**.

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