Select the incorrectly matched pair.

Options

A. Initiation codon - AUG, GUG
B. Stop codon - UAA, UAG, UGA
C. Methionine - AUG
D. Alanine - ACC, ACU, ACA and ACG

Answer

To solve the question of selecting the incorrectly matched pair, we will analyze each option given in the question step by step.

### Step-by-Step Solution:

1. **Understanding Codons**:
- Codons are sequences of three nucleotides that correspond to specific amino acids or signals during protein synthesis.

2. **Analyzing the First Option**:
- **Initiation Codon: AUGGUG**
- AUG is known as the start codon and is used in both prokaryotes and eukaryotes to initiate translation.
- GUG can also serve as a start codon, but it is primarily recognized in prokaryotes.
- Conclusion: This option is partially correct, as it contains both initiation codons, but it is not an incorrect match.

3. **Analyzing the Second Option**:
- **Stop Codon: A U A, A U G, U G A**
- Stop codons signal the termination of protein synthesis and do not code for any amino acid.
- The stop codons are UAA, UAG, and UGA.
- Conclusion: This option is incorrect because AUA and AUG are not stop codons.

4. **Analyzing the Third Option**:
- **Methionine: AUG**
- AUG codes for Methionine in eukaryotes and for formylated Methionine in prokaryotes.
- Conclusion: This option is correct.

5. **Analyzing the Fourth Option**:
- **Alanine: ACC, ACU, ACA, ACG**
- The correct codons for Alanine are GCU, GCC, GCA, and GCG.
- The codons provided (ACC, ACU, ACA, ACG) actually code for Threonine.
- Conclusion: This option is incorrect.

### Final Conclusion:
- The incorrectly matched pairs are:
- **Stop Codon: A U A, A U G, U G A** (as AUA and AUG are not stop codons).
- **Alanine: ACC, ACU, ACA, ACG** (as these codons do not code for Alanine).

### Answer:
The incorrect match is **D: Alanine (ACC, ACU, ACA, ACG)**.