Practice question

Pluripotent stem cells naturally originate from early embryonic sources capable of forming all three germ layers but not extraembryonic tissues. The inner cell mass of blastocyst, embryonic stem cells derived from it, and induced pluripotent stem cells created by reprogramming share core pluripotency networks Oct4, Sox2, Nanog. Bone marrow harbors multipotent hematopoietic and mesenchymal stem cells, not pluripotent cells under physiological conditions. It supports blood formation and stromal lineages within mesodermal limits. Distinguishing natural pluripotent origins from multipotent adult reservoirs prevents confusion about embryonic versus adult potency.