Examples of osmosis

In the animal cells

• Osmosis influences the shape and size of animal cells as there is no cell wall in animal cells.
• The red blood cells in humans are highly influenced by the osmotic pressure of blood. If the blood is too dilute, the RBCs shrink in size while they swell up and even burst if the blood is concentrated.
• Thus, in animals, the concentration of body fluids; blood plasma and tissue fluid, should be kept within strict limits.
• Another example of osmosis in animals is the shrinking of slugs on exposure to salt.
• The skin of slugs is a semi-permeable membrane that on exposure to salt, draws out water from the cells resulting in the shrinking of the cell and, in turn, the animal.

Figure: Effects of osmosis on cells in different tonic environments

In the plant cells

• The root system in plants takes up water from the soil via osmosis.
• The cells in the root of the plants have a semi-permeable membrane that allows the water in the soil to infiltrate into the roots influencing the guard cells.
• Another classic example of osmosis in plants is the swelling up and shrinking of potato cells when slices of potato are dipped in a hypotonic solution and hypertonic solutions respectively.