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Question #46525
The Question
NCERT states that modern-day lifestyles and 'protected environments provided early in life' have resulted in increased sensitivity to allergens. Based on the immunological principles of this 'hygiene hypothesis', which of the following best explains the physiological mechanism behind this exaggerated immune response?
Options
- A.
Reduced exposure to diverse microbes prevents adequate Th1 pathway stimulation, causing a shift towards a Th2-dominant response characterized by excessive IgE production and mast cell sensitization.
- B.
The lack of early pathogen exposure causes primary lymphoid organs to produce hyperactive T-cytotoxic cells that directly degranulate mast cells upon encountering harmless antigens.
- C.
An ultra-sterile environment leads to the suppression of the humoral immune system, forcing an exaggerated cell-mediated immune response involving massive IgG secretion.
- D.
Absence of diverse environmental antigens lowers the activation threshold of macrophages, causing them to release excessive histamine and serotonin during secondary exposure.
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
IgE|Sensitization|Resource_Partitioning|Environment
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Connecting the ecological concept of 'microbial niche exposure' to the physiological Th1/Th2 immune balance.
Students often memorize the 'protected environment' line in NCERT but fail to link it to the mechanism of IgE overproduction.
The distractors utilize 'Functional Confusion' (swapping mast cells for macrophages) and 'Typological Nuance' (swapping IgE for IgG or cell-mediated responses).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | Allergy Mechanism |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |