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Question #45985
The Question
A Long Day Plant (LDP) is exposed to a light period exceeding its critical threshold, successfully initiating the cascade that suppresses floral repressors and triggers the migration of florigen to the shoot apex. However, during microsporogenesis in the newly formed floral buds, a cytological anomaly prevents the terminalization of chiasmata. Which of the following statements is CORRECT regarding the physiological and genetic outcome?
Options
- A.
The plant will revert to vegetative growth because the failure of diakinesis retroactively inhibits florigen synthesis in the leaves.
- B.
Floral organ development will proceed normally, but the plant will produce aneuploid gametes due to the non-disjunction of homologous chromosomes during Anaphase I.
- C.
The microspore mother cells will bypass Meiosis I and directly enter Meiosis II, resulting in the formation of unreduced diploid pollen grains.
- D.
The photoperiodic induction will be nullified, and the shoot apical meristem will fail to differentiate into a floral meristem.
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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
Photoperiodism Thresholds|Terminalization of Chiasmata|FLC Gene Expression
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between the spatial/temporal timeline of physiological induction (photoperiodism in leaves) and cytological execution (meiosis in anthers).
Students often mistakenly assume a meiotic failure aborts the entire macroscopic flowering process.
Additionally, it tests the direct mechanical link between Diakinesis (terminalization) and Anaphase I (segregation), where failure leads to non-disjunction (aneuploidy).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Growth and Development - Class 11 |
| Concept | Photoperiodism Thresholds |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |