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Question #45955
The Question
In a plant tissue culture experiment, mature permanent parenchyma cells from a stem pith are induced to form an undifferentiated mass of dividing cells known as a callus. Which of the following statements correctly identifies the cellular phenomenon, the required cell cycle transition, and the hormonal prerequisite for this process?
Options
- A.
The cells undergo dedifferentiation by exiting the G0 quiescent stage to re-enter the cell cycle, strictly requiring the synergistic application of both auxin and cytokinin.
- B.
The cells undergo redifferentiation by entering the G0 phase from G1, triggered by a high auxin to low cytokinin ratio to form root apical meristems.
- C.
The cells undergo dedifferentiation by bypassing the G1 phase and directly entering the S phase, induced solely by high concentrations of cytokinin.
- D.
The cells undergo differentiation by maintaining their G0 arrest, which is facilitated by the antagonistic interaction between auxin and abscisic acid.
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
Auxin Polarity|G0 Phase Quiescence|Meristematic Activity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse 'Dedifferentiation' (regaining division capacity) with 'Redifferentiation' (losing it again to mature).
The trap also tests the integration of two distinct NCERT chapters: 'Plant Growth and Development' (Skoog and Miller's hormonal requirements for callus) and 'Cell Cycle and Cell Division' (understanding that mature parenchyma cells reside in the G0 phase and must re-enter G1 to divide).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Growth and Development - Class 11 |
| Concept | Differentiation vs Dedifferentiation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |