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Question #45950
The Question
A researcher treats an actively growing shoot apical meristem with a high concentration of Abscisic Acid (ABA). Consequently, the cells cease organogenesis but remain metabolically active. Which of the following statements correctly describes the molecular and cellular state of these meristematic cells?
Options
- A.
They undergo terminal differentiation, permanently losing their totipotency as ABA degrades the mitotic spindle apparatus.
- B.
They exit the G1 phase to enter the quiescent stage (G0), temporarily masking their totipotency due to the inhibition of Cyclin-dependent kinases.
- C.
They arrest in the G2 phase, maintaining totipotency but suspending all metabolic activities until ABA levels decline.
- D.
They dedifferentiate into permanent tissues, losing their Cyclin/CDK complexes and entering a state of irreversible cellular senescence.
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
Meristematic Totipotency|G0 Phase Quiescence|Equational Division Logic
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse the G0 phase (quiescence) with terminal differentiation or senescence, and misinterpret the NCERT phrase 'inactive stage' as 'metabolically inactive'.
This question tests the synthesis of macroscopic plant hormone physiology (ABA-induced dormancy) with microscopic cell cycle regulation (G1 to G0 transition via Cyclin/CDK inhibition), while ensuring the student understands that totipotency in G0 is merely masked, not permanently lost.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Growth and Development - Class 11 |
| Concept | Meristematic Totipotency |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |