Practice question

Stem cell pool expansion occurs through symmetric self-renewing division where mother produces two daughters retaining stem identity and potency. This mode dominates during embryonic development, regeneration after injury and early culture expansion driven by high Wnt, EGF and absence of differentiation cues like BMP. Asymmetric division maintains constant pool size generating one stem and one differentiating daughter, symmetric differentiating division depletes pool generating two differentiated cells, and population asymmetry describes stochastic balancing across population. Balanced control between symmetric self-renewal and asymmetric divisions governs tissue growth, aging and homeostasis preventing exhaustion.