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Question #45385
The Question
The onset of parturition in humans and the activation of Bacillus thuringiensis (Bt) toxin in target insects both require highly specific 'triggers' to initiate their respective cascades. Which of the following accurately contrasts the fundamental nature of these activation triggers?
Options
- A.
Parturition is initiated by mechanical stretch receptors activating a neuroendocrine positive feedback loop, whereas Bt toxin activation requires alkaline pH-induced solubilization followed by proteolytic cleavage.
- B.
Parturition is triggered by a sudden drop in maternal oxytocin levels, whereas Bt toxin is activated by the acidic environment of the insect foregut.
- C.
Parturition relies on the enzymatic conversion of a prohormone into active oxytocin in the uterus, whereas Bt toxin activation is a purely mechanical process driven by gut peristalsis.
- D.
Both processes fundamentally rely on a ligand-receptor mediated conformational change initiated directly by the fetal pituitary and the insect salivary glands, respectively.
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
Proteolytic_Cleavage|Alkaline_pH|Oxytocin_Release
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between a systemic neuroendocrine reflex (mechanical stretch triggering a hormonal positive feedback loop) and a localized biochemical processing event (environmental pH triggering enzymatic cleavage).
The trap relies on students confusing the specific environmental requirements (alkaline vs acidic pH) and the nature of the cascades (hormonal vs proteolytic).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Reproduction - Class 12 |
| Concept | Parturition Neuroendocrine Reflex |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |