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Question #47742
The Question
A researcher prepares competent E. coli cells using divalent cations and heat shock, successfully co-transforming them with two distinct recombinant plasmids, pX and pY. Both plasmids possess the identical origin of replication (ori) derived from pBR322. After several generations of culturing in a medium lacking selective pressure for pY, the bacterial population predominantly retains only pX, while pY is completely lost. Which of the following best describes the molecular cause of this phenomenon and its analogous evolutionary principle?
Options
- A.
The plasmids undergo homologous recombination due to shared sequences; analogous to Gene Flow.
- B.
The plasmids compete for the same replication machinery leading to competitive exclusion; analogous to Genetic Drift.
- C.
The host cell's restriction endonucleases selectively degrade pY; analogous to Natural Selection.
- D.
The divalent cations used during competent cell preparation inhibit pY replication; analogous to the Founder Effect.
Check Your Answer
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
PCR|Taq_Polymerase|Elution|DNA_Fragment
Why This Question Is Tricky
Common Mistakes
The Conceptual Pivot lies in synthesizing Biotechnology (function of 'ori') with Evolution (Genetic Drift).
Students usually memorize that 'ori' controls copy number, but fail to realize that two plasmids with the same 'ori' cannot coexist stably (Plasmid Incompatibility).
Mapping the random segregation and loss of a plasmid to the stochastic nature of Genetic Drift tests high-level interdisciplinary application.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biotechnology : Principles and Processes - Class 12 |
| Concept | Elution Process |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |