Question

In ureotelic animals, urea formed by
A. Cori’s Cycle
B. Krebs Cycle
C. Ornithine Cycle
D. CMP pathway

Answer 1

Urea is formed by ornithine in the ureotelic animals and helps in the conversion of excess amounts of amino acids into urea in the liver. With the process of deamination the extra protein present in the body degrades where the amine is removed and converted into the ammonia ions in the liver. And the urea forms into the liver transported into the kidney through circulation and finally gets excreted.

Complete answer:
Formation of ammonia with the deamination and transmission of biogenic amines of pyrimidine and purine obtained from the Amine group. And transport and storage of the ammonia as Alanine and Glutamine with the efficient transport and immediate utilization of ammonia for the synthesis of urea.
Acid base balance, amino sugars, non-essential amino acids, pyrimidine and purine are the functions of the ammonia present in the synthesis compounds. Disposal of ammonia excreted from the water in the form of aquatic animals and from uric acid in the form of reptiles and birds, and from urea in the form of nontoxic, water soluble products such as mammals.

Therefore the correct option is (C).

Note: Ornithine cycles help to form the urea from the ureotelic animals. Ornithine Cycle also known by the others name Krebs- Henseleit cycle and urea is the main nitrogenous excretory product obtained from the ureotelic animals. And the urea formed in the liver and regulated by the N-acetyl glutamate and excreted in the kidney after dissolving into the blood as a component of urine.