What is the process called in which cells become specialized in structure and function?

Differentiation is the process by which unspecialized cells, such as stem cells, develop into specialized cells that have distinct structures and functions. During differentiation, cells undergo changes in gene expression, leading to the formation of various cell types that make up different tissues and organs in the body. This process is crucial for the development of multicellular organisms, allowing for a diverse range of functions necessary for survival.

Transcription refers to the process of synthesizing RNA from a DNA template, which is an essential step in gene expression but does not directly describe the specialization of cells. Replication is the process of copying DNA, vital for cell division but unrelated to the specialization of cell types. Apoptosis is programmed cell death, a controlled process through which cells are eliminated, playing a role in development and homeostasis but again not related to the specialization of cells. Therefore, differentiation specifically captures the transformation of cells into their specialized forms.