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Question #46358
The Question
Read the following statements regarding the genetic and evolutionary basis of human blood group systems. Which of the following statements is INCORRECT?
Options
- A.
The structural variation between A and B antigens on the RBC membrane is due to different alleles of gene I encoding slightly different glycosyltransferase enzymes.
- B.
The antigenic polymorphism observed in the ABO blood group system is a direct phenotypic consequence of the degeneracy of the genetic code.
- C.
Despite the selective pressure of maternal-fetal incompatibilities, multiple alleles of the ABO system are maintained in the population via balancing selection.
- D.
Erythroblastosis fetalis occurs when maternal anti-Rh antibodies, which are of the IgG class, cross the placental interface and destroy fetal Rh+ erythrocytes.
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
ABO-Rh Incompatibility Logic|Genetic Code Degeneracy|Multiple_Alleles
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often conflate 'Degeneracy of the genetic code' (redundancy at the nucleotide level yielding the SAME protein) with 'Multiple allelism/Polymorphism' (variation at the genomic level yielding DIFFERENT proteins/phenotypes).
The trap relies on the student misinterpreting 'degeneracy' as a source of variation rather than a buffer against it.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Body Fluids and Circulation - Class 11 |
| Concept | ABO-Rh Incompatibility Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |