Practice question

Tissue renewal often involves intermediate transit-amplifying compartment that amplifies numerical output of rare, frequently quiescent stem cells efficiently. True stem cells divide infrequently, giving rise to rapidly cycling progenitor daughters that undergo predictable number of mitoses, for example four to six divisions in intestinal crypt or basal epidermis, before terminal differentiation into functional mature cells like absorptive enterocytes or cornified keratinocytes. This strategic hierarchy increases cell production without exhausting stem reserve, reduces mutation accumulation in precious stem genome, and allows fine tuning of tissue size in response to injury signals and mitogens.