My husband and I *love* to walk ...for hours and hours, and if we decide to go ahead with this potential trip - I'm going to need good shoes. These days, I have some reasonably good shoes for the most part - but they are 2-3 hour walking shoes, not necessarily good for 6+ hours of tromping around.
In cell biology, selective permeability is the property of a living cell membrane that allows the cell to control which molecules can pass through the membrane, moving into or out of the cell.
Examples of Selectively Permeable Membranes. Selectively permeable membranes can be found around a variety of cells and places. The most common example is the phospholipid bilayer cell membrane that surrounds every cell in our bodies. Another example of a selectively permeable membrane is the inner membranes of an egg. All cells in our body are surrounded by a phospholipid bilayer.