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Question #47590
The Question
A diploid angiosperm is cultivated in a controlled phytotron and exposed exclusively to monochromatic light of 700 nm during the critical phase of floral bud development. Which of the following represents the most probable cytological anomaly observed during microsporogenesis, and its underlying physiological cause?
Options
- A.
Normal haploid microspores are formed, as cyclic photophosphorylation in the tapetum provides adequate ATP for meiosis.
- B.
Formation of aneuploid or polyploid microspores, because the Red Drop effect induces an ATP deficit that impairs spindle fiber polymerization in Microspore Mother Cells.
- C.
Complete failure of exine formation, because the inactivation of Photosystem I prevents the tapetal cells from synthesizing sporopollenin.
- D.
Premature meiotic arrest at Prophase I, due to the accumulation of oxygen from hyperactive Photosystem II causing oxidative damage to the synaptonemal complex.
Check Your Answer
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
Microspore_Mother_Cell|Meiosis|ATP_Dependence
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating Plant Physiology (Photosynthesis/Red Drop) with Plant Reproduction (Microsporogenesis/Meiosis).
The trap relies on students memorizing the 'Red Drop' effect merely as a graph of quantum yield, without applying its metabolic consequences (severe ATP deficit) to energy-intensive cellular processes like spindle fiber formation.
It also tests the specific wavelength activation of photosystems to eliminate distractors (e.g., knowing >680nm inactivates PS II, halting oxygen evolution).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Photosynthesis in Higher Plants - Class 11 |
| Concept | Red Drop and Emerson Enhancement Effect |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |