Question

Which of the following is excreted in human urine?
(A) Ammonia
(B) Urea
(C) Uric acid
(D) Amino acid

Answer 1

Hint: Excretion is the important biological process in which the metabolic waste from the body is excreted. The organs like skin, liver, Kidney etc. are useful in the process of excretion. The kidney is known as the main excretory organ. The waste that is excreted by the kidney is urine.

Complete Answer:
- All the ureotelic organisms release the waste product as the urine. Urine is the liquid waste which is obtained from the byproduct of the metabolism. This is mainly excreted in the human and the animals.
- The metabolic waste products from the cell are transported in the blood and are carried by the veins to the liver. This waste is rich in nitrogenous compounds like ammonia, creatine, urea etc.
- The first part of the chemical separation is taking place in the liver.

The liver separates the ammonia from the blood. Then the blood moves to the kidney which is the main organ for the excretion. The kidney separates the urea from the blood by the uriniferous tubules. Absorption and reabsorption take place there. Then the collected urea is released as the urine by the urethra.

Thus, the option (B) is correct.

Note: In urine, along with the urea the other products like water, inorganic salts, creatinine, ammonia, pigmented products which are excreted from the blood are also present. Along with this waste, urochrome is also present, this gives yellow color to the urine.