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Question #45381
The Question
During implantation, the mammalian blastocyst acts as a semi-allograft but naturally evades maternal immune rejection. This localized immunological tolerance at the fetal-maternal interface prevents the destruction of the embryo. Which of the following statements regarding this phenomenon is INCORRECT?
Options
- A.
The syncytiotrophoblast acts as an immunological barrier by lacking classical MHC antigens, preventing recognition by maternal cell-mediated immunity.
- B.
If this tolerance mechanism fails, the implanting blastocyst would be rejected primarily by maternal T-lymphocytes.
- C.
The natural immunosuppressive environment at the implantation site functionally mimics Cyclosporin A, a bioactive molecule produced by the yeast Monascus purpureus.
- D.
Cyclosporin A, used clinically to prevent allograft rejection, acts by inhibiting T-cell activation, a mechanism naturally paralleled by the trophoblast.
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
Syncytiotrophoblast|Cyclosporin_A_Immunomodulation|Major_Histocompatibility_Complex
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Cross-chapter synthesis combining Human Reproduction (Implantation), Human Health (Cell-Mediated Immunity/Graft Rejection), and Microbes in Human Welfare.
The trap relies on 'Source Confusion'—students correctly associate Cyclosporin A with immunosuppression and graft tolerance but fail to notice the incorrect microbial source (Monascus purpureus instead of Trichoderma polysporum), a classic high-yield NEET trap.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Reproduction - Class 12 |
| Concept | Implantation and Syncytiotrophoblast |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |