Which one is not a termination codon ?

Options

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

Explanation

To determine which codon is not a termination codon, we need to understand the concept of codons in genetics.

### Step-by-Step Solution:

1. **Understand Codons**: Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids or signal the termination of protein synthesis.

2. **Identify Termination Codons**: There are three specific codons known as termination or stop codons. These codons do not code for any amino acids and signal the end of protein synthesis. The three termination codons are:
- UAA (Ochre)
- UAG (Amber)
- UGA (Opal)

3. **Examine the Options**: We need to analyze the given options to identify which one is not a termination codon. The options provided are:
- A. UAA
- B. UAG
- C. AUG
- D. UGA

4. **Evaluate Each Option**:
- **Option A (UAA)**: This is a termination codon.
- **Option B (UAG)**: This is also a termination codon.
- **Option C (AUG)**: This is not a termination codon; instead, it is the start codon that initiates protein synthesis.
- **Option D (UGA)**: This is a termination codon.

5. **Conclusion**: The codon that is not a termination codon is **AUG** (Option C).

### Final Answer:
**C. AUG** is not a termination codon.