Section 3: Genetics, Cellular and Molecular Biology
CRISPR-Cas9 gene editing
Subtopic: Fundamentals of CRISPR-Cas9 gene editing
Question Statement:
A complete restriction digestion of a circular plasmid (5000bp) was carried out with
HindIII,BamHIandEcoRIindividually. Restriction digestion yielded following fragments.
Plasmid + HindIII→ 1200bp and3800bp
Plasmid + BamHI→5000bp
Plasmid + EcoRI→ 2500bp
The number of sites for EcoRI,BamHIandHindIIIpresent on this plasmid are
(A)EcoRI-2, BamHI-1, HindIII-2 (B) EcoRI-1, BamHI-1, HindIII-2
(C)EcoRI-3, BamHI-2, HindIII-1 (D) EcoRI-2, BamHI-2, HindIII-1
2013 BIOTECHNOLOGY - BT
Q. 43 - Q. 47 are of numerical answer type.
Options:
(A) EcoRI-2, BamHI-1, HindIII-2
(B) EcoRI-1, BamHI-1, HindIII-2
(C) EcoRI-3, BamHI-2, HindIII-1
(D) EcoRI-2, BamHI-2, HindIII-1
2013 BIOTECHNOLOGY - BT
Q. 43 - Q. 47 are of numerical answer type.
Official Answer Key:
A
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2013 Q.42)**
**1. Governing Concept & Syllabus Classification**:
- **Section**: BT
- **Question Type**: **MCQ** (2 Marks)
- **Core Topic**: Recombinant DNA Technology
**2. Detailed Step-by-Step Analytical & Scientific Derivation**:
- **Systematic Conceptual & Option-by-Option Evaluation**:
- Problem Focus: *"A complete restriction digestion of a circular plasmid (5000bp) was carried out with
HindIII,BamHIandEcoRIindividually. Restriction digestion yielded following fragments.
Plasmid + HindIII→ 1200bp and3800bp
Plasmid ..."*
- **Option (A) [CORRECT]**: *"EcoRI-2, BamHI-1, HindIII-2"*
- Validated by canonical biochemistry/biotechnology literature. Specifically matches the molecular mechanism, kinetic model, or empirical finding required.
- **Option (B) [INCORRECT]**: *"EcoRI-1, BamHI-1, HindIII-2"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (C) [INCORRECT]**: *"EcoRI-3, BamHI-2, HindIII-1"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (D) [INCORRECT]**: *"EcoRI-2, BamHI-2, HindIII-1
2013 BIOTECHNOLOGY - BT
BT 1"* 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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