Before You Begin
Question #46598
The Question
A recombinant bacterial strain, transformed with a biocontrol plasmid via the calcium ion and heat-shock method, is released into a field to synergistically suppress root pathogens. The field is subjected to extreme diurnal thermal gradients. Subsequently, the biocontrol efficacy declines, and the recombinant gene is found in the native soil microflora. All of the following statements correctly explain the underlying genetic and ecological principles of this phenomenon, EXCEPT:
Options
- A.
Fluctuating environmental thermal stress can induce plasmid instability and subsequent loss in the recombinant biocontrol agent.
- B.
The thermal gradients act identically to laboratory heat-shock (42°C), creating permanent pores in the native microflora's cell wall for continuous DNA uptake.
- C.
The presence of the recombinant gene in native microflora indicates unintended horizontal gene transfer, altering the natural biotic interaction matrix.
- D.
The loss of biocontrol synergy is partly due to the metabolic burden on native microflora expressing the newly acquired recombinant gene.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Horizontal_Gene_Transfer|Recombinant_Microbes|Eco-Safety
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: The trap relies on the distinction between 'transient' and 'permanent' structural changes during competent cell preparation.
Students often memorize 'heat shock creates pores' without realizing that the process (heat followed by ice) is designed to be strictly temporary.
Failing to recognize that permanent pores would be lethal to the bacteria is a common conceptual gap.
Additionally, it tests the application of lab-based biotechnology principles to real-world ecological scenarios (horizontal gene transfer and plasmid instability).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Microbes in Human Welfare - Class 12 |
| Concept | Biocontrol Agents Synergy |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |