Question

The initial chemical part of excretion occurs in
A) Kidneys
B) Liver
C) Lungs
D) Both A and B

Answer 1

Excretion is the process of removal of metabolic waste from the body of an organism. In case of vertebrates the excretion takes place through lungs, kidney and skin. Through excretion toxic substances, gaseous waste, water is eliminated from the body in the form of sweat, exhaled air or urine.

Complete answer:
The excretion is the process of removal of waste from the body of the living organism. The main organs of excretion are
i) Skin through which water and other salts are eliminated from the body.
ii) Lungs- It is the organ of excretion through which the gaseous waste like carbon dioxide is eliminated out from the body. The carbon dioxide is eliminated through the exhalation.
iii) Liver- The foremost chemical excretion occurs in the liver. It detoxifies chemicals by the secretion of bile which moves to the intestine for metabolism of food. Liver is the organ in which the drugs are also metabolised. The liver also synthesises the proteins thrombin and prothrombin which are essential blood clotting factors.
iv) Kidney- Kidney is the main organ of excretion. The nitrogenous waste like urea is filtered through the kidney. Kidney also helps in eliminating excess salts and water from the body.

Thus the correct answer is option ‘B’.

Note: Excretion is an important physiological process taking place in our body. If the unwanted substances are not removed from the body, then the substances can lead to poisoning or toxicity. The kidneys produce urine in which the excess urea and other substances are eliminated.