Fluid mosaic is a term used to describe the current model of the cell membrane. Cell membranes are basically double layers (bilayers) of molecules called phospholipids.A mosaic is a structure made up of many different parts. Mainly because of the way the plasma membrane is made up. It is fluid because it can wave and wobble like fluid, a bit sticky though. Due to the phospholipids sticking together. It is called mosaic because there are various proteins stuck inside the fluid creating a kind of patchwork or mosaic