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Question #46259
The Question
In a plant exhibiting an epipetalous androecium (e.g., Petunia), the localized application of Abscisic Acid (ABA) at the base of the corolla tube during the early bud stage completely halts microsporogenesis in the anthers. Which of the following provides the most accurate anatomical and physiological explanation for this phenomenon?
Options
- A.
ABA induces cellulase and pectinase activity at the corolla base, causing premature abscission that mechanically severs the shared vascular supply to the adnate stamens.
- B.
ABA acts as a systemic growth inhibitor, directly diffusing into the anther locules to arrest the meiosis of microspore mother cells at Prophase I.
- C.
The epipetalous condition forces the stamens to rely directly on the thalamus for nutrition, which is blocked by ABA-induced callose plugs in the filament.
- D.
Premature petal senescence, accelerated by cytokinins, causes the endothecium to lose its hygroscopic nature, thereby preventing pollen maturation.
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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
Epipetalous|Solanaceae|Abscisic_Acid
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating floral morphology (epipetaly) with plant growth regulators (ABA-induced abscission).
The common misconception is viewing floral whorls as physiologically independent entities.
Students often fail to realize that structural adhesion (epipetaly) creates a shared vascular dependency, making the androecium highly vulnerable to the premature abscission of the corolla.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Morphology of Flowering Plants - Class 11 |
| Concept | Androecium Cohesion/Adhesion |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |