Subtopic: Fundamentals of Biomolecules, enzyme kinetics
Question Statement:
A truncated polypeptide is synthesized due to a nonsense mutation. Where would you introduce
another mutation to obtain a full-length polypeptide?
(A) Ribosomal protein gene (B) Transfer RNA gene
(C) DNA repair gene (D) Ribosomal RNA gene
Options:
(A) Ribosomal protein gene
(B) Transfer RNA gene
(C) DNA repair gene
(D) Ribosomal RNA gene
Official Answer Key:
B
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2012 Q.12)**
**1. Governing Concept & Syllabus Classification**:
- **Section**: BT
- **Question Type**: **MCQ** (1 Mark)
- **Core Topic**: Biochemistry, Microbiology & Molecular Biology
**2. Detailed Step-by-Step Analytical & Scientific Derivation**:
- **Systematic Conceptual & Option-by-Option Evaluation**:
- Problem Focus: *"A truncated polypeptide is synthesized due to a nonsense mutation. Where would you introduce
another mutation to obtain a full-length polypeptide?..."*
- **Option (B) [CORRECT]**: *"Transfer RNA gene"*
- Validated by canonical biochemistry/biotechnology literature. Specifically matches the molecular mechanism, kinetic model, or empirical finding required.
- **Option (A) [INCORRECT]**: *"Ribosomal protein gene"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (C) [INCORRECT]**: *"DNA repair gene"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (D) [INCORRECT]**: *"Ribosomal RNA gene"* does not satisfy the precise boundary conditions or molecular specificity.
**3. Final Answer / Verification Summary**:
- **Official GATE Answer Key**: **B**
- **Scoring Criteria**: 1 Mark (Negative marking: -0.33 marks).
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