Practice question

Stem cells exhibit long-term self-renewal enabling indefinite expansion while retaining potency to generate differentiated progeny through asymmetric or symmetric divisions throughout organismal lifespan. Progenitor or transit-amplifying cells show limited replicative lifespan, gradually exhaust after several divisions, and possess restricted lineage potential with lower telomerase activity. While both can proliferate and differentiate, only stem cells reconstitute entire tissue over organism lifetime and rescue ablated tissue upon transplantation assays. This distinction is demonstrated in hematopoietic reconstitution and epidermal lineage tracing, underpinning regenerative medicine strategies and therapeutic targeting.