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.
In a nutshell, the cell membrane lets some things through and restricts the passage of other things. For this reason, it is said to be selectively permeable. A very interesting topic of study is the blood / brain barrier. The cells of the brain do not allow just any molecule to cross into the brain from the blood. They have set up amazing little elevators that select and classify before transportation.