Practice question

Adult or tissue-specific stem cells populate most organs possessing high turnover or regenerative demand, including neural subventricular zone progenitors, hepatic oval cells, muscle satellite cells, and epidermal basal layer keratinocytes. They maintain full genomic complement, DNA repair capacity, and mitotic competence enabling self-renewal. Mature mammalian red blood cells extrude nucleus, ribosomes, and organelles during terminal differentiation steps to accommodate maximal hemoglobin content and enhance vascular deformability. Lacking chromatin, transcription, and division machinery, they cannot dedifferentiate or serve as stem cell reservoir, making them incapable of supporting sustained blood cell production despite abundance.