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Question #46248
The Question
A mutation in a dicot plant severely impairs the differentiation of the root apical meristem (RAM), specifically reducing mitotic activity in the zone of cell division. Despite this, the plant survives under controlled hydroponic conditions and successfully transitions to the reproductive phase. However, its typical highly branched, indeterminate (racemose) inflorescence is altered to a solitary or sparsely branched determinate (cymose) pattern. Which of the following best explains the physiological basis for this altered floral architecture?
Options
- A.
A deficit in xylem-translocated cytokinins from the roots prevents adequate lateral shoot bud proliferation at the shoot apex.
- B.
An accumulation of phloem-translocated auxins from the roots induces early termination of the main floral axis.
- C.
The absence of root-derived florigen prevents the continuous indeterminate growth of the primary inflorescence axis.
- D.
A reduction in phloem-translocated gibberellins from the root cap fails to maintain the vegetative growth of the floral axis.
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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 Region Differentiation|Inflorescence|Phytohormones
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that 'cytokinins promote cell division' but fail to integrate their specific site of synthesis (root apices), their transport pathway (xylem), and their macroscopic morphological effect (overcoming apical dominance to maintain complex, branched inflorescences).
The trap lies in confusing the source of the floral transition signal (florigen from leaves) with the source of the architectural branching signal (cytokinins from roots).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Morphology of Flowering Plants - Class 11 |
| Concept | Inflorescence Types |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |