**Question:** Same aminoacid is coded by multiple codons due to following

A. AUG (start codon)
B. UAA/UAG (stop codons)
C. Codon reassignment
D. Antisense RNA interference

**Correct Answer:** Same aminoacid is coded by multiple codons due to **Codon reassignment**.

**Core Concept:** In molecular biology, codon reassignment is a phenomenon where a particular amino acid is encoded by more than one codon. This can occur through alternative initiation codons, such as AUG and UAA/UAG, or through reassignment of a stop codon to encode an amino acid.

**Why the Correct Answer is Right:** Codon reassignment allows for more flexibility in genetic information storage and translation. By using different codons to encode the same amino acid, the genetic code can more efficiently utilize available codons and optimize translation efficiency.

**Why Each Wrong Option is Incorrect:**

A. **AUG (start codon)** is correct, as it is the start codon that initiates protein synthesis. Codon reassignment does not involve changing the start codon.

B. **UAA/UAG (stop codons)** are correct as they are the stop codons that terminate protein synthesis. However, codon reassignment does not involve changing stop codons to encode amino acids.

C. **Codon reassignment** is the correct answer, as it involves the reassignment of codons to encode amino acids. This allows for more flexibility in encoding amino acids without changing the start or stop codons.

D. **Antisense RNA interference** is a separate mechanism that involves the interaction between complementary RNA strands to regulate gene expression. Codon reassignment is distinct from this process and focuses on altering the genetic code to encode amino acids.

**Clinical Pearl:** Understanding codon reassignment is essential for understanding genetic regulation and protein synthesis. It plays a role in genetic engineering, where codons can be reassigned to encode specific amino acids, allowing for precise control of protein production.