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Question #46821
The Question
A temperate dicot tree is subjected to persistent, severe water stress at the onset of the favorable growing season (spring). Which of the following best describes the physiological and anatomical modulation of its secondary growth in response to this environmental stress?
Options
- A.
The vascular cambium remains highly active but produces narrow vessels to increase hydraulic conductivity and prevent cavitation.
- B.
The vascular cambium exhibits reduced activity, prematurely forming latewood-like xylary elements with narrow vessels, which increases hydraulic resistance but minimizes the risk of embolism.
- C.
The vascular cambium increases its activity to produce early wood with wider vessels, attempting to maximize water extraction from the drying soil and decreasing hydraulic resistance.
- D.
The vascular cambium ceases division, and the existing spring wood vessels immediately develop tyloses to increase water transport efficiency.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Spring Wood|Autumn Wood|Vessel Diameter|Plant Growth and Development
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often mistakenly assume that during a drought, a plant will attempt to maximize water uptake by forming wider vessels (Option C).
However, the actual physiological adaptation is defensive.
The plant prioritizes the integrity of the water column over volume, reducing cambial activity to form narrow vessels that resist embolism, directly linking NCERT's anatomical descriptions of spring/autumn wood to the biophysics of water transport.
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 |