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Question #45867
The Question
The transition from Griffith's transforming principle to the Hershey-Chase experiment established DNA as the genetic material. Considering the evolutionary necessity of stable biogenesis and the molecular mechanics of DNA, which of the following statements is INCORRECT?
Options
- A.
Avery, MacLeod, and McCarty demonstrated that transformation of the R strain is inhibited by DNase, proving that the molecule later labeled with 32P by Hershey and Chase is the genetic material.
- B.
The evolutionary shift from random abiogenic polymers to stable biogenesis required DNA polymerases to possess 3' → 5' exonuclease activity to proofread the newly synthesized strand during replication.
- C.
During the expression of the 32P-labeled viral genome, the non-coding strand (3' → 5') acts as the template, resulting in an mRNA transcript that is identical in sequence to the non-coding strand, except for Uracil replacing Thymine.
- D.
If the transforming principle were RNA, it would be more prone to mutation due to the reactive 2'-OH group on its ribose sugar, making it less suitable for long-term stable biogenesis.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Streptococcus_pneumoniae|T2_Phage|RNA_Polymerase_Binding
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse the nomenclature of 'coding' vs 'non-coding' strands with their actual transcriptional outputs.
A common misconception is assuming that because the 'non-coding' strand is the template, its exact sequence is copied into mRNA.
In reality, the mRNA is complementary to the template (non-coding) strand, making it identical to the coding strand.
This tests deep reading of NCERT's Molecular Basis of Inheritance.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Molecular Basis of Inheritance - Class 12 |
| Concept | Hershey-Chase Isotopic Labeling |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |