Section 3: Genetics, Cellular and Molecular Biology
DNA replication, transcription, translation
Subtopic: Fundamentals of DNA replication, transcription, translation
Question Statement:
For their efficient translation, eubacterial mRNAs possess a Shine-Dalgarno sequence for its
recognition by an anti-Shine-Dalgarno sequence (ASD) in the ribosomes. The correct statement is
Options:
(A) PAM250, PAM120, PAM100
(B) PAM100, PAM120, PAM250
(C) PAM250, PAM100, PAM120
(D) PAM120, PAM250, PAM100
Official Answer Key:
A
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2014 Q.54)**
**1. Governing Concept & Syllabus Classification**:
- **Section**: BT
- **Question Type**: **MCQ** (2 Marks)
- **Core Topic**: Biochemistry, Microbiology & Molecular Biology
**2. Detailed Step-by-Step Analytical & Scientific Derivation**:
- **Systematic Conceptual & Option-by-Option Evaluation**:
- Problem Focus: *"For their efficient translation, eubacterial mRNAs possess a Shine-Dalgarno sequence for its
recognition by an anti-Shine-Dalgarno sequence (ASD) in the ribosomes. The correct statement is..."*
- **Option (A) [CORRECT]**: *"ASD is present in 5S rRNA"*
- Validated by canonical biochemistry/biotechnology literature. Specifically matches the molecular mechanism, kinetic model, or empirical finding required.
- **Option (B) [INCORRECT]**: *"ASD is present in 23S rRNA"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (C) [INCORRECT]**: *"ASD is present in 16S rRNA"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (D) [INCORRECT]**: *"ASD is formed by the interaction of the 16S rRNA with the 23S rRNA upon doc"* does not satisfy the precise boundary conditions or molecular specificity.
**3. Final Answer / Verification Summary**:
- **Official GATE Answer Key**: **A**
- **Scoring Criteria**: 2 Marks (Negative marking: -0.66 marks).
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