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Question #46510
The Question
A patient recovers from a viral infection, successfully establishing immunological memory. Several months later, they are re-infected by a variant of the same virus species that has undergone extensive antigenic drift, significantly altering its surface glycoproteins. Which of the following statements accurately describes the subsequent humoral immune response?
Options
- A.
The pre-existing memory B-cells will mount a rapid anamnestic response, producing high titers of IgG to neutralize the variant.
- B.
The immune system will bypass the lag phase due to the presence of memory T-cells, which will directly activate naive B-cells.
- C.
The patient will exhibit a primary immune response characterized by a distinct lag phase and the initial secretion of IgM antibodies.
- D.
A secondary immune response will be triggered, but it will exclusively utilize IgA antibodies to neutralize the mutated virus at mucosal surfaces.
Check Your Answer
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
Antigenic Drift|Memory B-cells|Natural Selection
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often assume that re-infection by the 'same pathogen species' (e.g., Influenza) automatically guarantees a secondary (anamnestic) response.
The trap lies in failing to realize that immunological memory is strictly epitope-specific, not species-specific.
When antigenic variation occurs, the host's immune system treats the variant as a completely novel pathogen, necessitating a primary response (IgM first, with a lag phase).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | Primary vs Secondary Immune Response |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |