Section 3: Genetics, Cellular and Molecular Biology
CRISPR-Cas9 gene editing
Subtopic: Fundamentals of CRISPR-Cas9 gene editing
Question Statement:
In nature, Agrobacterium tumefaciens mediated infection of plant cells leads to
P. crown gall disease in plants
Q. hairy root disease in plants
R. transfer of T-DNA into the plant chromosome
S. transfer of Ri-plasmid into the plant cell
(A) S only (B) P and R only (C) Q and S only (D) Q only
Options:
(A) S only
(B) P and R only
(C) Q and S only
(D) Q only
Official Answer Key:
B
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2013 Q.31)**
**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: *"In nature, Agrobacterium tumefaciens mediated infection of plant cells leads to
P. crown gall disease in plants
Q. hairy root disease in plants
R. transfer of T-DNA into the plant chromosome
S. transfer of Ri-plasm..."*
- **Option (B) [CORRECT]**: *"P and R only"*
- Validated by canonical biochemistry/biotechnology literature. Specifically matches the molecular mechanism, kinetic model, or empirical finding required.
- **Option (A) [INCORRECT]**: *"S only"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (C) [INCORRECT]**: *"Q and S only"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (D) [INCORRECT]**: *"Q only"* does not satisfy the precise boundary conditions or molecular specificity.
**3. Final Answer / Verification Summary**:
- **Official GATE Answer Key**: **B**
- **Scoring Criteria**: 2 Marks (Negative marking: -0.66 marks).
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