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Question #46220
The Question
A transgenic variety of Daucus carota (carrot) is engineered using RNA interference (RNAi) to specifically silence the ACC synthase gene in its root tissues. Based on the principles of phytohormone action and sink-source dynamics, which of the following is the most likely phenotypic consequence?
Options
- A.
Accelerated radial swelling of the tap root due to the removal of ethylene's inhibitory effect on cell division.
- B.
Failure of the radicle to undergo storage modification, resulting in an elongated root and reallocation of biomass to the shoot.
- C.
Profuse development of root hairs to maximize absorption, driven by a compensatory increase in abscisic acid.
- D.
Complete suppression of root cap formation, leading to a loss of gravitropism and stunted plant growth.
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
Root_Modifications|Growth_Rate_Quantification|Absolute_vs_Relative_Growth
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that ethylene 'promotes root growth and root hairs' (NCERT) but fail to integrate that it specifically inhibits longitudinal elongation in favor of radial swelling.
The trap lies in linking post-transcriptional gene silencing (RNAi) of a Plant Growth Regulator to macroscopic sink-source biomass reallocation, testing the synthesis of Biotechnology (Class 12) and Plant Physiology (Class 11).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Morphology of Flowering Plants - Class 11 |
| Concept | Root Modifications |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |