Question

Kidneys are not the only organs of excretion their work is supplemented by

• A. Liver
• B. Skin
• C. Heart
• D. Large intestine

Answer 1

The correct option is B Skin

Kidney is the main excretory organ in man. It helps in filtration of blood and maintains osmoregulation. Accessory organs of excretion are liver, lungs and skin. Liver directly supplement the function of kidney. It helps in formation of urea which is a major excretory product. The extra proteins in the body are degraded by the process of deamination where the NH${}_2$ group is removed and it is converted into ammonium ions in the liver. The ammonium ions enter urea cycle and get converted into urea. The urea formed in liver is transported to kidney through circulation and finally gets excreted.

Skin and lungs takes part in excretion but they do not supplement the kidneys directly. Skin helps in secretion of oil, water and salts by sweat and sebaceous gland. Lungs helps in excretion of carbon dioxide.

So, the correct answer is option"skin."