Question

Put a drop of blood in three solutions.(a)pure water(b)salt solution (c)water containing 5ml gulcose and 0.9% of Nacl. Answer according to class 9

Answer 1

 Best Answer:  When animal cells such as red blood cells are placed in a hypotonic solution (distilled water), water molecules diffuse into the red blood cells by osmosis. The red blood cells gain water and swell and finally burst because they have no cell walls. the red blood cells are said to undergo haemolysis. 

When red blood cells are placed in a hypertonic solution such as 4% sodium chloride solution (salt solution). water molecules diffuse out of the cell by osmosis. Water is rapidly lost. The red blood cells will shrivel and probably die. This process is called crenation of red blood cells. 

If red blood cells are immersed in an isotonic solution (0.85% sodium chloride solution), water molecules flow across the membrane at the same rate in both directions. There is no net movement of water molecules across the membrane. The red blood cells maintain their shape. The concentration in the red blood cells is the same as the concentration in the environment, that is 0.85% sodium chloride solution.