Section 3: Genetics, Cellular and Molecular Biology
CRISPR-Cas9 gene editing
Subtopic: Fundamentals of CRISPR-Cas9 gene editing
Question Statement:
A single base pair of DNA weighs 1.1 × 10-21 grams. How many picomoles of a plasmid vector of
length 2750 bp are contained in 1 g of purified DNA?
(A) 0.30 (B) 0.55 (C) 0.25 (D) 0.91
2012 BIOTECHNOLOGY - BT
Options:
(A) Q.30
(B) Q.55
(C) Q.25
(D) Q.91
2012 BIOTECHNOLOGY - BT
Official Answer Key:
B
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2012 Q.30)**
**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 single base pair of DNA weighs 1.1 × 10-21 grams. How many picomoles of a plasmid vector of
length 2750 bp are contained in 1 g of purified DNA?..."*
- **Option (B) [CORRECT]**: *"0.55"*
- Validated by canonical biochemistry/biotechnology literature. Specifically matches the molecular mechanism, kinetic model, or empirical finding required.
- **Option (A) [INCORRECT]**: *"0.30"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (C) [INCORRECT]**: *"0.25"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (D) [INCORRECT]**: *"0.91
2012 BIOTECHNOLOGY - BT
BT 5/16"* 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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