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Question #46290
The Question
A plant species genetically programmed for a racemose inflorescence is subjected to severe drought stress. This environmental stress triggers the premature and ectopic activation of floral meristem identity genes directly at the terminal shoot apical meristem (SAM). Which of the following morphological outcomes will be observed?
Options
- A.
The inflorescence will shift to a cymose pattern because the terminal SAM converts into a floral bud, halting indeterminate growth.
- B.
The inflorescence will maintain its racemose pattern but exhibit basipetal succession due to the premature senescence of the main axis.
- C.
The plant will develop solitary axillary flowers because the terminal SAM loses its meristematic polarity without forming a flower.
- D.
The inflorescence will exhibit accelerated indeterminate growth due to the stress-induced suppression of MADS-box genes.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Meristematic Polarity|Inflorescence Types|Law of Limiting Factors
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often rote-memorize 'Racemose = Indeterminate' and 'Cymose = Determinate' without understanding the underlying developmental biology—specifically, the fate of the Shoot Apical Meristem (SAM).
The trap tests whether the student understands that environmental stress can override genetic programming (phenotypic plasticity), forcing a premature conversion of the SAM into a floral bud, thereby shifting the morphological pattern from indeterminate to determinate.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Anatomy of Flowering Plants - Class 11 |
| Concept | Meristematic Polarity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |