What best defines cellular differentiation?

Cellular differentiation refers to the process by which a less specialized cell becomes more specialized in function and structure. This is a critical biological process that allows for the development of various cell types with distinct roles within an organism. During differentiation, stem cells and progenitor cells undergo changes in gene expression, which leads to the development of unique characteristics and functions needed for specific tissues or organs.

For example, a stem cell can differentiate into muscle cells, nerve cells, or blood cells, each serving different functions. This transformation involves changes at both the physiological and genetic levels, resulting in cells that perform specialized tasks essential for the organism's overall functioning.

Understanding cellular differentiation is fundamental in fields such as developmental biology, regenerative medicine, and therapeutic applications, where the manipulation of stem cells and their differentiation pathways can lead to innovative treatments for various diseases.