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Question #46506
The Question
A developing fetus receives maternal IgG across the placenta, whereas a 6-month-old infant receives a recombinant DNA vaccine for Hepatitis B. Both mechanisms ensure the infant's survival against specific pathogens. Synthesizing the principles of immunology and evolution, which of the following statements is strictly correct regarding these two protective mechanisms?
Options
- A.
The former confers natural passive immunity and the latter artificial active immunity; functionally, they act as analogous mechanisms by achieving convergent adaptive outcomes through entirely different biological pathways.
- B.
Both mechanisms rely on the generation of memory B-cells in the infant, representing homologous evolutionary traits derived from a common vertebrate ancestor.
- C.
The former confers natural active immunity via pre-formed antibodies, while the latter confers artificial passive immunity; they represent divergent evolution of the mammalian immune system.
- D.
The former provides natural passive immunity and the latter artificial active immunity; however, they are considered homologous because both ultimately utilize immunoglobulins to neutralize pathogens.
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
Analogous Organ Structure|Active Immunity|Passive Immunity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize 'Active vs Passive' immunity but fail to apply evolutionary concepts (Homology vs Analogy) to physiological processes.
The primary trap (Option D) relies on the misconception that because both processes ultimately involve 'antibodies', they must be homologous.
This question forces the student to recognize that the 'mechanism of acquisition' (vertical maternal transfer vs. horizontal endogenous priming) dictates their evolutionary relationship as analogous (convergent function for survival).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | Active vs Passive Immunity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |