Initiation codon in eukaryotes

Options

A. UGA
B. CCA
C. AGA
D. AUG

Answer

**Step-by-Step Solution:**

1. **Understanding Codons**: A codon is a sequence of three nucleotides in mRNA that corresponds to a specific amino acid or a stop signal during protein synthesis.

2. **Types of Codons**: There are two main types of codons:
- **Start Codons (Initiation Codons)**: These signal the beginning of protein synthesis.
- **Stop Codons**: These signal the termination of protein synthesis.

3. **Identifying the Start Codon in Eukaryotes**:
- In eukaryotes, the most common initiation codon is **AUG**.
- AUG codes for the amino acid **methionine**, which is the first amino acid incorporated into a nascent polypeptide chain during translation.

4. **Recognizing Stop Codons**:
- The stop codons are UAG, UAA, and UGA. These do not initiate protein synthesis but rather signal the end of the translation process.

5. **Conclusion**: The initiation codon in eukaryotes is **AUG**.

**Final Answer**: The initiation codon in eukaryotes is AUG.

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