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Question #47711
The Question
During a horizontal gene transfer event, a bacterial population takes up linear DNA fragments containing a tetracycline resistance gene. However, an environmental toxin completely inhibits the ATP-dependent activity of the host's DNA ligase. When plated on a tetracycline-rich medium, the population collapses. Which of the following represents the precise molecular failure causing this collapse?
Options
- A.
Failure of DNA polymerase to synthesize RNA primers required for the transcription of the resistance gene.
- B.
Inability to form hydrogen bonds between complementary nitrogenous bases of the alien DNA and the host genome.
- C.
Inability to catalyze phosphodiester bond formation between adjacent 3'-OH and 5'-phosphate ends, preventing stable integration.
- D.
Inability of restriction endonucleases to cleave the host's circular chromosome to accommodate the alien DNA.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Restriction Enzyme Cleavage Physics|Ethidium Bromide Visualization|Downstream Processing
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Differentiating between the spontaneous annealing of sticky ends (hydrogen bonds) and the enzyme-driven sealing of the DNA backbone (phosphodiester bonds).
A common misconception is that complementary base pairing alone is sufficient for stable recombinant DNA integration.
Students must also recognize that linear DNA fragments are unstable in bacteria unless covalently integrated via ligase.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biotechnology : Principles and Processes - Class 12 |
| Concept | Restriction Enzyme Cleavage Physics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |