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Question #45131
The Question
A farmer integrates transgenic Bt-cotton with soil applications of Trichoderma and Mycorrhizal biofertilizers to maximize crop yield and disease resistance. Based on the biochemical triggers and interactions of these agents, which of the following statements is INCORRECT?
Options
- A.
Trichoderma species are free-living fungi that act as effective biocontrol agents against root-borne pathogens via competition and antibiosis.
- B.
The acidic exudates released by Mycorrhizae into the rhizosphere facilitate the premature solubilization and activation of leached Bt protoxins, harming non-target soil microfauna.
- C.
The activation of the Bt protoxin into a functional Cry protein requires an alkaline pH, which is provided by the insect midgut but typically absent in humic-acid-rich soil.
- D.
While the Bt gene provides targeted resistance against specific insect pests, Mycorrhizae synergistically provide phosphorus nutrition and tolerance to root pathogens.
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
Bacillus thuringiensis|Trichoderma|Mycorrhiza
Why This Question Is Tricky
Common Mistakes
The 'Conceptual Pivot' is the strict pH dependency of Bt toxin activation.
The trap exploits a 'Mechanism Misconception', where students might assume that fungal exudates or soil enzymatic activity universally degrade or activate biological molecules.
By remembering the specific NCERT fact that Bt requires an ALKALINE pH, the student can deduce that acidic rhizosphere conditions prevent, rather than facilitate, its activation.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biotechnology and Its Applications - Class 12 |
| Concept | Bt Toxin Activation Trigger |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |