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Question #45765
The Question
An alien invasive aquatic weed secretes a novel allelochemical that specifically inhibits calcium-dependent actin polymerization in eukaryotic cells. If this toxin accumulates in a native freshwater ecosystem, which of the following physiological or ecological processes will be most directly impaired?
Options
- A.
The locomotion of native ciliated protozoans like Paramecium, leading to a collapse of the primary consumer level.
- B.
The formation of pseudopodia in native Amoeba and the phagocytic activity of macrophages in indigenous fish.
- C.
The assembly of the mitotic spindle in native phytoplankton, halting primary productivity.
- D.
The flagellar motility of zoospores in native aquatic fungi, preventing their reproduction.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Actin|Alien_Species_Invasion_Impacts|Cellular_Locomotion
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between the specific cytoskeletal elements responsible for different types of cellular movement.
A common misconception is lumping all cytoskeletal functions together.
Students must recall that pseudopodia/amoeboid movement relies on microfilaments (actin), whereas cilia, flagella, and spindle fibers rely on microtubules (tubulin).
The question synthesizes Cell Biology (cytoskeleton) with Ecology (alien species invasion).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Locomotion and Movement - Class 11 |
| Concept | Amoeboid Movement Mechanism |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |