Question

Blood may be purified by:
(A) Dialysis
(B) Electro osmosis
(C) Coagulation
(D) Filtration

Answer 1

Hint: Blood is a colloidal solution. All the given methods are used for the purification of suspensions or colloids. The methods of purification of colloids depends on the nature and properties of the colloidal solution. To answer this question, you must recall the given purification methods and their principles. The process used is a common process used after kidney failure.

Complete step by step solution:
Blood is a colloidal solution and the impurities present in the blood are in the form of crystalloids. They are removed by diffusing the mixture, here blood, through an animal membrane or a parchment. Dialysis uses the same process and can thus be used for the purification of blood in artificial kidneys. The membrane in the dialysis machine allows the small waste product and the small ionic particles through it. The relatively bigger colloidal sized particles like Haemoglobin are not permitted to pass the membrane. The waste products now separated from the necessary blood particles are then flushed out hence purifying blood.
Thus, the correct answer is A.

Note:
The purification of blood is the primary function of kidneys. It removes the excess waste and fluid from the body cleaning the blood. This waste is then sent to the bladder and eliminated from the body in the form of urine. When however the kidneys fail to function or collapse, we have to rely on the process of dialysis to do the function of the kidneys. Dialysis is the process which uses a special filter called an artificial kidney to remove the waste materials from blood. In cases of acute or the sudden failure of kidneys, dialysis is necessary to ensure the proper functioning of the body.