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Question #45406
The Question
Adult stem cells reside in a specialized microenvironment known as the 'stem cell niche' (e.g., the base of the Crypts of Lieberkühn), which maintains a strict concentration gradient of paracrine factors. If a pathological event disrupts this niche gradient—analogous to the destruction of an ecotone leading to competitive exclusion—which of the following is the most likely immediate consequence for the resident multipotent stem cells?
Options
- A.
They undergo premature differentiation or apoptosis due to the deprivation of self-renewal and survival signals.
- B.
They initiate uncontrolled mitotic proliferation due to the sudden loss of contact inhibition.
- C.
They spontaneously dedifferentiate into totipotent embryonic stem cells to regenerate the damaged microenvironment.
- D.
They permanently arrest in the G2 phase of the cell cycle until the paracrine gradient is re-established.
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
Stem Cells|Niche Overlap|Resource Partitioning
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often equate 'loss of cellular regulation' directly with 'cancer' or uncontrolled proliferation (Option B).
However, the stem cell niche provides positive survival and self-renewal signals.
Removing these signals is akin to removing a species' fundamental ecological niche—it results in cell death (apoptosis) or forced maturation (differentiation), not unchecked growth.
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 |