Introduction
The processes through which cells allow molecules to pass through their membranes are diffusion and osmosis. The process through which molecules move through a selectively permeable membrane, moving from an area of high concentration to an area of low concentration until and unless they are both uniformly arranged both inside and outside the cell membrane is called diffusion. This process is not difficult for smaller molecules but large molecules face problems moving through the cytoplasm of the cell or even through the pores in the membrane on their own. On the other hand, osmosis is the process through which water molecules diffuse in and out of the cell. The water molecules in osmosis do not get balanced out on the inside and outside of the membrane but instead they depend on the amount of non-permeable solute in the water. These molecules are dissolved substances in the water which are not able to pass through the cell membrane (Reece et al., 2014). A cell can be placed in three types of solutions, the rate of diffusion depends on the concentration of the solution the cell is placed in. In hypotonic solution, more water is present on the outside of the cell than the inside, which means the net diffusion of water is flowing inside the cell causing the cell to swell up. Hypertonic solutions on the other hand contain less water outside the cell membrane, causing water to leave the cell which in turn shrivels up the cell. Isotonic solutions have equal concentration both inside and outside the cell which means there is no net movement in or out of the cell. These processes are very important in understanding how cells work in different solutions. Since animal cells have no cell walls, they burst in hypotonic solutions and shrivel up in hypertonic solutions. Plant cells on the other hand do not burst in hypotonic solutions because of their large water conducting vacuoles and cell walls but still tend to shrivel up in hypertonic solutions. Osmosis...