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Question #45767
The Question
A novel pathogen secretes a toxin that completely inhibits the polymerization of actin microfilaments in host macrophages. If a patient infected with this pathogen is tested a week later using an indirect ELISA (designed to detect host antibodies against the pathogen), what will be the most likely diagnostic outcome and its primary physiological reason?
Options
- A.
False negative; inhibition of amoeboid movement prevents phagocytosis, halting MHC-II antigen presentation and subsequent B-cell activation.
- B.
True positive; failure of the innate cellular barrier forces an immediate, T-cell independent hyper-production of antibodies.
- C.
False negative; the toxin directly denatures the primary antibodies circulating in the blood plasma, preventing detection.
- D.
True positive; microfilament inhibition only arrests diapedesis, while dendritic cells continue to present antigens via MHC-I to stimulate humoral immunity.
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
Molecular_Diagnosis_by_ELISA|Primary_vs_Secondary_Immune_Response|Amoeboid_Mechanism
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize 'ELISA detects antibodies' and 'Macrophages perform phagocytosis' as isolated facts.
The trap lies in failing to connect the cytoskeletal mechanics of amoeboid movement (Class 11 Locomotion) to the initiation of the acquired humoral immune response and its diagnostic implications (Class 12 Human Health and Biotech).
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 |