The Ecology of Humans (7-29) Mitosis


A bone marrow transplant is done by injecting stem cells from a donor into the blood stream of a recipient. These injected stem cells mysteriously find their way to the marrow where they make their home.

Stem cells are unspecialized mother cells found in all multicellular organisms. Stem cells divide through mitosis, a complex and highly regulated process: splitting into 2 by making a copy of the many various parts of a eukaryotic cell, including the nucleus, cytoplasm, organelles, and membrane.

A daughter cell can differentiate from the mother cell, becoming more specialized, and thereby taking on roles which the mother cell never had. Differentiation can dramatically alter a cell’s size, shape, membrane potential, metabolic activity, and response to communications from other cells.

Energetically regulated, differentiation physically expresses via tightly controlled modifications in gene expression. Although there are exceptions, where genetic material itself is rearranged, typically the DNA sequence itself remains the same during differentiation. Genetic expression is an intricate process, where a reproduced daughter cell takes on different physical characteristics as well as different behaviors, despite ostensibly having the same genome.

By this inheritance process new cells can be born that take on a new template of existence. Cellular inheritance includes selectively passing on the memories from the previous generation of cell, mother to daughter.