Before You Begin
Question #46527
The Question
Read the following statements regarding Adenosine Deaminase (ADA) deficiency, its gene therapy, and immune tolerance. Which of the following statements is INCORRECT?
Options
- A.
ADA is essential for purine metabolism; its absence causes an accumulation of toxic metabolites that primarily induce apoptosis in developing T-lymphocytes.
- B.
During standard gene therapy where functional ADA cDNA is introduced into cultured peripheral blood lymphocytes, these cells must subsequently undergo negative selection in the thymus to prevent autoimmunity upon re-infusion.
- C.
Introducing the functional ADA gene into bone marrow hematopoietic stem cells at early embryonic stages provides a permanent cure and allows for normal central tolerance development.
- D.
Autoimmunity represents a failure of the immune system to recognize 'self' antigens, a property normally acquired during T-cell maturation in primary lymphoid organs.
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
Thymus|ADA_Enzyme|Lymphocytes
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that 'gene therapy involves lymphocytes' and 'T-cells mature in the thymus' without synthesizing the timeline.
The trap relies on failing to distinguish between the developmental stage of the cells being modified (mature peripheral blood lymphocytes vs. immature stem cells) and the anatomical location where negative selection occurs.
Mature infused cells bypass the thymus entirely.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | Autoimmunity Principles |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |