Aug 11, 2003. JGR is and always has been one of the most original games ever made. The graffitti system is really entertaining, especially when you can JGR is and always has been one of the most original games ever made. The graffitti system is really entertaining, especially when you can make your own designs.
A selectively permeable membrane is a membrane that allows some substances to pass through easily, while other substances pass through very slowly or not at all. All cell membranes, including the plasma membrane, are selectively permeable. selectively permeable membrane is a membrane that allows some substances to pass through easily, while other substances pass through very slowly or not at all. All cell membranes, including the plasma membrane, are selectively permeable.
The reason that the cell membrane is considered to be 'semi-permeable' is because there are certain materials that can pass through the cell membrane (e.g. hydrocarbons and oxygen cross through the cell membrane as they can be dissolved into the lipid layer - other examples include small polar molecules.