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Question #45403
The Question
During embryonic development, a specific lineage of stem cells fails to undergo terminal differentiation and instead forms a rapidly proliferating neoplastic mass. Based on the principles of cell cycle regulation and oncogenesis, which of the following molecular events most accurately explains this anomaly?
Options
- A.
A gain-of-function mutation in a proto-oncogene has bypassed the G1/S checkpoint, preventing the cells from entering the G0 phase.
- B.
A loss-of-function mutation in cellular oncogenes (c-onc) has induced dedifferentiation, reverting the cells to a totipotent state.
- C.
The cells have undergone premature senescence due to the overactivation of telomerase, leading to uncontrolled proliferation.
- D.
Upregulation of tumor suppressor genes has inhibited contact inhibition, forcing the cells into continuous mitotic cycles.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Stem Cells|Proto-oncogenes|Oncogenes
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse the mutational mechanics of cancer (Gain-of-function for proto-oncogenes vs.
Loss-of-function for tumor suppressor genes) and often fail to synthesize the connection between the G0 phase (Cell Cycle) and terminal differentiation (Embryonic Development).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Reproduction - Class 12 |
| Concept | Differentiation of Stem Cells |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |