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Question #47517
The Question
In a dense tropical rainforest, a population of mosses (Funaria) receives continuous rainfall, providing optimal surface moisture for zooidogamy. However, researchers note a complete absence of sporophyte formation in this population. Assuming no genetic defects, which of the following statements correctly identifies the physiological bottleneck preventing the gametophyte-to-sporophyte transition?
Options
- A.
The canopy shade enriches far-red light, locking phytochrome in the inactive Pr state and blocking the hormonal pathways necessary for sex organ maturation.
- B.
The lack of direct sunlight prevents the dependent sporophyte from performing the light reaction, causing it to abort immediately after syngamy.
- C.
High moisture levels inhibit the conversion of the active Pfr form to the inactive Pr form, suppressing the chemotactic secretion of sucrose by the archegonia.
- D.
Shading promotes the accumulation of the active Pfr form, which antagonizes the auxin-cytokinin balance required for antherozoid motility.
Check Your Answer
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
Productivity Ratios|Decomposition Rate Modifiers|Bryophyte Dependence Mechanics
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often rigidly associate bryophyte reproduction solely with the availability of water (zooidogamy) and overlook that photomorphogenesis (light quality via phytochrome) is a universal prerequisite for plant developmental transitions.
The trap relies on confusing the active (Pfr) and inactive (Pr) states of phytochrome and misunderstanding the spectral quality of canopy shade (which is rich in far-red light, not red light).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Bryophyte Dependence Mechanics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |