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Question #47514
The Question
A researcher is cultivating Funaria spores in an artificial nutrient medium. The spores germinate successfully to form a green, creeping, and branched filamentous network. However, the culture fails to develop upright axes with spirally arranged leaves, effectively trapping the organism in a sterile, vegetative phase. Based on the principles of phytohormone-mediated morphogenesis, which of the following conditions in the medium is the primary cause of this developmental arrest?
Options
- A.
A high Auxin to Cytokinin ratio, which inhibits the induction of lateral buds from the secondary protonema.
- B.
A high Cytokinin to Auxin ratio, which induces excessive rhizoid differentiation at the expense of the leafy shoot.
- C.
A deficiency of Gibberellic acid, which prevents the elongation of the sporophytic seta and capsule.
- D.
An accumulation of Abscisic acid, which directly inhibits the meiotic division of spore mother cells.
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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
Bryophyte Dependence Mechanics|Nutrient Immobility|Antherozoids
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating the morphological lifecycle of mosses (Plant Kingdom) with the physiological principles of plant tissue culture and hormonal ratios (Plant Growth and Development).
Students often memorize the moss lifecycle (spore -> protonema -> leafy stage) and hormone functions in isolation.
The trap lies in failing to connect that 'lateral bud' formation in mosses is governed by the exact same Cytokinin/Auxin morphogenetic rules as angiosperm organogenesis.
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 |