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Question #46146
The Question
An experimental chemical that specifically inhibits the calcium-ion ATPase pumps of the sarcoplasmic reticulum is injected into the coelomic fluid of Pheretima (earthworm). Which of the following represents the most immediate and lethal physiological consequence?
Options
- A.
Tetanic paralysis of the lateral hearts, leading to systemic asphyxiation as the loss of blood circulation destroys the concentration gradient required for cutaneous respiration.
- B.
Flaccid paralysis of the lateral hearts, causing blood to pool in the ventral vessel and preventing oxygenation of the dissolved hemoglobin in the plasma.
- C.
Immediate cessation of cutaneous respiration due to the accumulation of lactic acid in the moist body wall, which physically blocks gaseous exchange.
- D.
Hyperactivity of the lateral hearts, leading to rapid depletion of ATP and a subsequent leftward shift of the oxygen dissociation curve due to localized hypoxia.
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
Lateral_Hearts|Dorsal_Vessel|Lactic_Acidosis
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that earthworms respire through their skin but fail to synthesize that cutaneous respiration is entirely dependent on continuous vascular perfusion to maintain the diffusion gradient.
Additionally, it tests the classic physiological trap of muscle mechanics: failure of Ca2+ reuptake causes sustained contraction (tetany), whereas failure of Ca2+ release causes flaccidity.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Animal Kingdom - Class 11 |
| Concept | Annelida Circulatory System |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |