<span>A liquid that can easily pass through cell membranes is water. That is what is used in determining the concentration of the solute inside a living cell. You can place the cells in different osmotic environments. Then you observe and determine the environment that causes no uptake of water.</span>
The major purpose of the cell membrane is to regulate the types of substances that enter the cells and leave the cell, thus, it is a semi permeable structure.
The structure of the cell membrane help the cell in regulating the amount of the water inside the cell because, when the optimum amount of water is inside the cell, the membrane will not allow the pasage of water molecules into the cell again.
And in a situation, where the concentration of substance inside the cell is above the normal concentration, the cell membrane will allow the required amount of water to flow into the cell in order to reduce the concentration.
Also, the phospholipid bilayers that are found in the cell membrane help to regulate water homeostasis of the cell by using its hydrophobic tail to repel water molecules and thus keep them out or inside of the cells.
If you remove a secondary consumer then, primary consumers have the chance to overpopulated and Tertiary consumers underpopulate or die off because there's no secondary consumers to eat
