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Question #47484

Difficulty: 8/10 | 🟢 Free

The Question

The transition from vegetative mycelium to a complex basidiocarp in Agaricus is governed by an intracellular secondary messenger cascade. When a researcher introduces a specific chelator that binds $Ca^{2+}$ ions into the culture, fruiting body formation is completely arrested. Which of the following physiological events in humans, involving the same signaling ion, is INCORRECTLY described?

Options

A.
In skeletal muscle fibers, its release from the sarcoplasmic reticulum unmasks myosin-binding sites on actin.
B.
It acts as a crucial secondary messenger in the intracellular signaling cascade of peptide hormones like FSH.
C.
During the repolarization phase of an axonal action potential, its rapid efflux restores the resting membrane potential.
D.
At the chemical synapse, its influx into the presynaptic knob triggers the exocytosis of neurotransmitter vesicles.

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Regulatory_Failure

Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.

Concepts Behind This Question

Basidiomycetes_Reproductive_Structure|Recombination_Nodule_Function|Basidiospore_Development

Why This Question Is Tricky

Common Mistakes

Conceptual Pivot: Cross-kingdom application of secondary messengers.

Students must first deduce that the chelator targets Calcium (a universal signaling ion).

The trap relies on confusing the specific ions responsible for action potential phases ( $Na^+$ for depolarization, $K^+$ for repolarization) with $Ca^{2+}$ , which is responsible for synaptic transmission, not axonal repolarization.

Quick Facts About This Question

Question Information

Subject	Biology
Chapter	Biological Classification - Class 11
Concept	Basidiomycetes Reproductive Structure
Difficulty	8
Cognitive Load	5
Target Solve Time	120 sec
Access	Free