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Question #46820
The Question
During the later stages of a xerarch succession in a tropical equatorial region, a dicot tree establishes itself in an environment where temperature and water availability remain uniformly constant throughout the year. If a cross-section of its main trunk is analyzed, which of the following anatomical features will be observed?
Options
- A.
Distinct annual rings formed by alternating bands of early wood and late wood, driven primarily by the tree's internal biological clock.
- B.
A uniform secondary xylem lacking distinct annual rings, as vascular cambium activity is not subjected to seasonal climatic fluctuations.
- C.
A complete absence of secondary xylem, as pioneer and early seral woody species in xerarch succession only exhibit primary growth to conserve metabolic energy.
- D.
A secondary xylem composed entirely of autumn wood to prevent cavitation, driven by the constant hydraulic stress of the xerarch environment.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Spring Wood|Autumn Wood|Primary Succession|Hydrarch Succession
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often rote-memorize 'dicot trees = annual rings' without understanding the environmental driver (seasonal variation) behind cambial activity.
The trap in Option D exploits the logical assumption that hydraulic stress requires narrow vessels, tricking students into misapplying the seasonal concept of 'autumn wood' to a non-seasonal environment.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Anatomy of Flowering Plants - Class 11 |
| Concept | Spring vs Autumn Wood |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |