Which one of the following is the starter codon ?

Options

A. UGA
B. UAA
C. UAG
D. AUG

Answer

**Step-by-Step Solution:**

1. **Understanding Codons**: Codons are sequences of three nucleotides found in RNA or DNA that correspond to specific amino acids or signal the termination of protein synthesis.

2. **Types of Codons**: There are two main types of codons:
- **Start Codons**: These initiate the process of translation. The most common start codon is AUG.
- **Stop Codons**: These signal the termination of translation. The common stop codons are UAA, UAG, and UGA.

3. **Identifying the Options**: The question provides four options: UGA, UAA, UAG, and AUG.

4. **Analyzing Each Option**:
- **UGA**: This is a stop codon.
- **UAA**: This is also a stop codon.
- **UAG**: This is another stop codon.
- **AUG**: This is the start codon and also codes for the amino acid methionine.

5. **Conclusion**: From the analysis, the only codon that serves as a starter codon is **AUG**.

**Final Answer**: The starter codon is **AUG**.

---