Cellulose.
no cell acts as a cell wall. cell walls are made of a two layers of lipids.
Cnidarians.
It has two cell layers.
cell wall and cell membraine
cell membrane and cell wall
Cnidaria are diploblastic animals, in other words they have two main cell layers, while more complex animals are triploblasts having three main layers. The two main cell layers of cnidarians form epithelia that are mostly one cell thick.
The semipermeable barrier made of two layers are called the Lipid Bilayer. They are in almost every living organism. The Hydrophilic heads are on the in and outside layer. Viruses are also made from the lipid bilayer and all of the membranes around the cell.
there are 2 layers. one for each side. like a sandwich and the layers are the bread. there are two of them so they can hold together the inside :]
phospholipids
A hydra typically has two cell layers: an outer layer of epithelial cells and an inner layer of gastrodermal cells. These layers are separated by a jelly-like extracellular matrix called the mesoglea.
A photovoltaic (PV) cell is primarily made of two thin layers of semiconductor materials, typically silicon. One layer is doped with phosphorus to create an n-type layer, which has an excess of electrons, while the other is doped with boron to form a p-type layer, which has a deficiency of electrons (or an excess of holes). This p-n junction between the two layers creates an electric field, enabling the conversion of sunlight into electricity.
Endoderm and ectoderm.