Which model describes the structure of cell membranes?

The fluid mosaic model accurately describes the structure of cell membranes by illustrating how their components, such as phospholipids, proteins, cholesterol, and carbohydrates, are organized and interact. In this model, the membrane is depicted as a dynamic and flexible structure, with phospholipid molecules arranged in a bilayer that can move and flow, similar to a fluid. This fluidity allows proteins and other molecules to move laterally within the membrane, contributing to its functional versatility, including cell signaling, transport, and communication.

The "mosaic" aspect of the model reflects the diverse array of proteins embedded within or attached to the lipid bilayer, each serving various roles such as receptors, channels, or structural components. This combination of fluidity and diversity is crucial for the functions of the cell membrane, making the fluid mosaic model a foundational concept in cell biology.

The other models and theories listed do not pertain to the specific structure of cell membranes: the homozygous model relates to genetics, cell theory describes the fundamental properties of cells, and the differentiation model pertains to how cells become specialized in function.