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Question #45786
The Question
Rigor mortis is a post-mortem condition characterized by profound muscular rigidity. Based on the sliding filament theory, which of the following statements accurately explains the primary molecular basis of this phenomenon?
Options
- A.
Depletion of ATP prevents the detachment of the myosin head from the active site of F-actin.
- B.
Absence of ATP prevents the hydrolysis required to cock the myosin head, permanently locking it in a relaxed state.
- C.
Failure of the ATP-dependent calcium pumps causes continuous cross-bridge cycling and sustained active contraction.
- D.
Post-mortem accumulation of lactic acid irreversibly denatures the troponin-tropomyosin complex, exposing active sites permanently.
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
Muscle_Fatigue_Factors|Creatine_Phosphate|Lactic_Acid
Why This Question Is Tricky
Common Mistakes
The Conceptual Pivot lies in the dual role of ATP in muscle mechanics.
Students often associate ATP solely with providing energy for contraction (the power stroke).
However, the NCERT explicitly highlights that ATP binding is the limiting reagent for cross-bridge detachment (relaxation).
Option C serves as a 'Common Half-Truth' trap: while calcium pumps do fail without ATP, this leads to a static lock, not 'continuous cycling'.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Locomotion and Movement - Class 11 |
| Concept | Sliding Filament Theory Mechanics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |