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Question #47567
The Question
A commercial forestry project attempts to cultivate Pinus for timber and resin extraction in a heavily fungicided, nutrient-supplemented soil. Despite the artificial addition of soluble phosphates and optimal irrigation, the Pinus seeds completely fail to germinate and establish. According to NCERT principles of plant taxonomy and physiology, which of the following best explains this systemic failure?
Options
- A.
Pinus seeds possess a highly impermeable seed coat that strictly requires fungal cellulases for scarification prior to germination.
- B.
The fungicidal treatment destroyed the obligate mycorrhizal fungi, without which Pinus seeds cannot germinate or establish due to an inherent physiological dependency.
- C.
The absence of soil fungi prevented the formation of coralloid roots, leading to severe nitrogen deficiency during the early seedling stage.
- D.
The artificial addition of soluble phosphates created an osmotic imbalance, as Pinus roots are exclusively adapted to absorb phosphorus in its insoluble organic form.
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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
Chlorophyceae|Flagellar_Insertion|Phaeophyceae|Organelle_Polarity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize the anatomical associations (Pinus = Mycorrhiza, Cycas = Coralloid roots) but miss the physiological depth of the word 'obligate'.
The trap lies in the premise of 'nutrient-supplemented soil'.
A student might logically deduce that if phosphates are artificially provided, the plant no longer needs the fungus.
However, NCERT explicitly states the relationship is obligate for germination and establishment, meaning the biological interaction itself is a non-negotiable prerequisite for the seed's developmental cascade.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Chlorophyceae Flagellar Insertion |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |