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Question #46831
The Question
A population of woody dicotyledonous plants is subjected to a prolonged, extreme arid climatic shift. Assuming the population possesses sufficient genetic variation, which of the following statements regarding its evolutionary and anatomical adaptation is INCORRECT?
Options
- A.
Directional selection will favor individuals with enhanced dedifferentiation of the outer cortical cells to form a highly active extra-stelar cambium.
- B.
The population's mean phenotype will shift towards producing a thicker phellem, as its suberized cell walls are impervious to water.
- C.
Natural selection will favor a symmetric increase in phellogen activity, producing equal layers of heavily suberized phellem and phelloderm to maximize desiccation resistance.
- D.
If the population lacks the developmental plasticity to adjust cork cambium activity, it will face strong negative selection pressure due to compromised water conservation.
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
Phellogen|Natural Selection Directionality|Xerophytic Adaptations
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often conflate the properties of the three periderm layers.
The trap relies on two specific NCERT details: (1) Phellogen activity is asymmetric (more active on the outer side), and (2) Only the phellem (cork) is suberized and impervious to water, whereas the phelloderm (secondary cortex) remains parenchymatous.
Assuming both layers become suberized to fight aridity is a logical but biologically incorrect extrapolation.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Anatomy of Flowering Plants - Class 11 |
| Concept | Periderm Components |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |