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Question #46822
The Question
In a perennial dicot tree, a targeted mutation disrupts the synthesis of Abscisic Acid (ABA) during the late growing season, eliminating its antagonistic effect against growth-promoting hormones. Based on the principles of secondary growth and plant growth regulators, which of the following would be the most likely consequence on the differentiation of the secondary xylem?
Options
- A.
Tyloses will rapidly proliferate into the peripheral sapwood, rendering the entire stem non-conductive.
- B.
The central secondary xylem will fail to accumulate tannins and resins, delaying heartwood formation and compromising pathogen resistance.
- C.
The unchecked action of Gibberellins will directly induce the deposition of suberin in the xylem parenchyma, forming early heartwood.
- D.
The vascular cambium will prematurely produce narrow-lumen vessels, accelerating the formation of autumn wood.
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
Heartwood|Sapwood|Abscisic Acid (ABA) Antagonism
Why This Question Is Tricky
Common Mistakes
Synthesizing Plant Anatomy (Heartwood/Sapwood) with Plant Physiology (PGRs).
The conceptual pivot is recognizing that heartwood formation is not merely a passive aging process, but an active, hormonally regulated developmental transition linked to ABA-induced dormancy.
Students often fail to connect ABA's antagonistic role against Gibberellins with the anatomical cessation of xylem conduction and the deposition of secondary metabolites.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Anatomy of Flowering Plants - Class 11 |
| Concept | Heartwood vs Sapwood |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |