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Question #46132
The Question
A researcher isolates a vertebrate skeletal muscle fiber and a live specimen of Pleurobrachia (a Ctenophore). Both are exposed to a highly specific toxin that irreversibly inhibits the active transport pumps responsible for intracellular calcium sequestration into the endoplasmic/sarcoplasmic reticulum. What will be the most likely effect on their respective locomotory mechanisms?
Options
- A.
Both the vertebrate muscle and Pleurobrachia will immediately undergo flaccid paralysis due to the inability to initiate a power stroke.
- B.
The vertebrate muscle will enter a state of sustained contraction, while the locomotory movement of Pleurobrachia will remain largely unaffected.
- C.
The vertebrate muscle will fail to initiate contraction, and the ciliated comb plates of Pleurobrachia will permanently cease beating.
- D.
The vertebrate muscle will undergo sustained contraction, and the ciliary dynein ATPases in Pleurobrachia will be competitively inhibited.
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
Ctenophora Locomotion|Calcium Dynamics|Cross-bridge Cycling Energy
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Differentiating the molecular mechanisms of locomotion (actin-myosin sliding filament vs. tubulin-dynein ciliary beating) and understanding the specific role of Ca2+ pumps.
Common Misconception: Students often confuse the inhibition of Ca2+ release (which prevents contraction) with the inhibition of Ca2+ sequestration (which prevents relaxation, causing tetanus), and incorrectly assume ciliary locomotion relies on the same SR calcium dynamics as skeletal muscle.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Animal Kingdom - Class 11 |
| Concept | Ctenophora Locomotion |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |