Cells that make up multicellular organisms are typically:

In multicellular organisms, cells are often specialized to perform distinct functions, which is referred to as differentiation. This process allows cells to develop unique structures and functions that contribute to the organism's overall complexity and efficiency. For example, muscle cells are specialized for contraction, nerve cells for signaling, and epithelial cells for protection and absorption.

Differentiation occurs through various mechanisms, including gene expression changes, where specific genes become active or inactive, leading to the development of a cell's unique characteristics. This specialization is essential for maintaining the various functions needed for the organism’s survival, growth, and development.

In contrast, unicellular organisms consist of a single cell that carries out all life processes, and multinucleated cells typically refer to specific types of cells like muscle fibers that can have multiple nuclei but are not a defining characteristic of multicellularity. Polyploid cells contain more than two homologous sets of chromosomes, which can occur in certain circumstances but is not a universal trait of multicellular organisms.