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Question #45973
The Question
A dark-grown dicot seedling exhibits the classic ethylene-induced 'triple response'. The parenchymatous tissue from its swollen axis is excised and cultured on a nutrient medium containing specific concentrations of Auxin and Cytokinin to induce dedifferentiation. Which of the following statements correctly describes the physiological fate of this tissue?
Options
- A.
It will undergo redifferentiation to form a highly thickened cork layer due to the synergistic action of ethylene and auxin.
- B.
It will lose its structural commitment to the triple response morphology and revert to an unorganized meristematic state.
- C.
It will immediately differentiate into a normal, elongated shoot axis due to the antagonistic effect of cytokinin on ethylene.
- D.
It will maintain its swollen morphology because ethylene-induced cellular changes in the primary plant body are irreversible.
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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
Ethylene|Differentiation vs Dedifferentiation|Cytokinin
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse the concepts of dedifferentiation and redifferentiation.
A common misconception is assuming that adding growth hormones to override ethylene will immediately result in a 'normal' organized plant part (Option C).
However, the exact process of dedifferentiation first strips the cell of its morphological commitment, reverting it to an unorganized meristematic state (callus) before any redifferentiation can occur.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Growth and Development - Class 11 |
| Concept | Ethylene Triple Response |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |