Every afternoon you walk by the school cafeteria and buy a can of pop from the vending machine. You know that pop is not good fo
r you, but buying it is a tough habit to break. Suppose that you start walking a different route so you don’t pass the vending machines. What have you changed to try to break your habit?
You can't resist not buying a pop whenever you pass in front of a vending machine. You know it's unhealthy to consume a pop this often, but you can't avoid the vending machine that's on your way. One way to avoid this is to change your environment, that is, to avoid walking the path that has vending machines, but instead taking a different path, a different environment that does not have vending machines that influence you to buy a pop.
All cells have an outer plasma membrane that regulates not only what enters the cell, but also how much of any given substance comes in. Unlike prokaryotes, eukaryotic cells also possess internal membranes that encase their organelles and control the exchange of essential cell components.
