Q.34 A single stem cell undergoes 10 asymmetric cell divisions.
The number of stem cells at the end is ________
Single Stem Cell 10 Asymmetric Divisions: Stem Cell Count Explained
In asymmetric cell division, a stem cell divides to produce one stem cell and one differentiated cell, maintaining a constant stem cell number despite each division. For a single stem cell undergoing 10 such divisions, the stem cell count remains 1.
Correct Answer
1
This holds because each division replaces the original stem cell with an identical one, while the other daughter differentiates and exits the stem cell pool.
Asymmetric Division Mechanics
Asymmetric division ensures tissue homeostasis by balancing self-renewal and differentiation. The parent stem cell partitions fate determinants unequally, so one daughter inherits stemness factors (self-renews) and the other gets differentiation signals. After 10 cycles starting from one stem cell, only that one lineage of stem cell persists, yielding 1 total.
Common Options Explained
Multiple-choice options often mislead by confusing division types:
- 1 (Correct): Asymmetric mode keeps stem cells at initial count (1).
- 10: Might assume one new stem per division, ignoring replacement; actually produces 10 differentiated cells, not stems.
- 11: Symmetric misconception (1 original + 10 new); asymmetric yields no net gain.
- 1024 (210): Symmetric proliferative error, where each division doubles all cells; irrelevant here.
- 0: Assumes full differentiation; contradicts self-renewal in asymmetric model.
Why It Matters in Biology
This mechanism prevents stem cell exhaustion or tumors, vital in contexts like your genetics and plant biology studies.[web:1][web:5] In plants, similar divisions occur in meristems for growth control.[web:9]
