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Question #47505
The Question
A researcher isolates photosynthetic parenchymatous cells from a young haploid prothallus of a fern and cultures them in vitro. Instead of maturing to produce gametangia, the cells lose their structural identity and proliferate into an unorganized mass of actively dividing cells, effectively truncating the gametophytic generation. Which of the following best explains this phenomenon and the specific hormonal condition responsible?
Options
- A.
The cells underwent redifferentiation to form a diploid sporophyte due to a high Auxin to Cytokinin ratio.
- B.
The cells underwent dedifferentiation to form a haploid callus due to a balanced ratio of Auxin and Cytokinin.
- C.
The cells underwent differentiation to form ectopic shoot meristems due to a high Cytokinin to Auxin ratio.
- D.
The cells underwent dedifferentiation to form a diploid callus due to the synergistic action of Auxin and Gibberellins.
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
Diakinesis|Pachytene|Crossing Over|Alternation of Generations
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating 'Plant Growth and Development' (Dedifferentiation & Phytohormones) with 'Plant Kingdom' (Haplodiplontic life cycle).
Students often fail to realize that haploid gametophytic cells can undergo dedifferentiation just like diploid sporophytic cells.
The trap tests the exact hormonal ratio (balanced Auxin:Cytokinin) required for callus formation versus organogenesis, and the preservation of ploidy during dedifferentiation.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Haplontic-Diplontic Life Cycle Transitions |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |