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Question #46210
The Question
A biotechnologist attempts to modify root architecture by introducing a novel gene directly into the Root Apical Meristem (RAM) using the biolistic (gene gun) method. Post-bombardment, the plantlets fail to establish a primary root axis, exhibit a complete loss of gravitropism, and eventually die. Which of the following best explains the anatomical and physiological basis for this systemic failure?
Options
- A.
Mechanical necrosis from high-velocity microparticles destroyed the statolith-containing root cap and the RAM, halting primary elongation and directional growth.
- B.
The heavy metal microparticles induced rapid, uncontrolled division of the quiescent centre, exhausting the meristematic potential of the primary root.
- C.
Physical destruction of the pericycle by the microparticles prevented the establishment of the primary root axis and subsequent lateral root emergence.
- D.
The introduced DNA triggered an unintended RNA interference (RNAi) pathway, degrading auxin receptors in the zone of elongation.
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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
Root System Architecture|Biolistics/Gene Gun Physics|Biotechnology
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often get distracted by advanced molecular biology buzzwords (like RNAi, mutation, or quiescent centre exhaustion) when evaluating biotechnology questions.
The pivot here requires grounding the high-tech method (Biolistics) in its actual physical reality (high-velocity heavy metal bombardment) and applying it to basic NCERT plant anatomy (RAM and root cap functions).
Failing to recognize the physical damage caused by the gene gun leads to selecting complex, but biologically incorrect, molecular mechanisms.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Morphology of Flowering Plants - Class 11 |
| Concept | Root System Architecture |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |