Question

d. None of these
Which organisms excrete urea as the major nitrogenous waste?
a. Ammonotelic
b. Uricotelic
c. Ureotelic
d. None of these​

Answer 1

Answer:

c

Explanation:

Nitrogenous wastes include ammonia, uric acid, and urea. Some aquatic animals excrete ammonia into the surrounding water before it can build up to toxic concentrations in their tissues. A few terrestrial animals, including some snails and wood lice, vent it directly into the air. But many animals, humans included, convert ammonia to some less toxic nitrogenous waste such as uric acid or urea. Uric acid is produced both from ammonia and by the break down of nucleotides from nucleic acids. Uric acid is insoluble in water and forms crystals that are excreted as a crystalline paste, so little fluid loss results. This is an important water-conserving adaptation in many terrestrial animals, including insects, certain reptiles, and birds. Urea, the principal nitrogenous waste product of amphibians and mammals, is synthesized in the liver from ammonia and carbon dioxide by a sequence of reactions known as the urea cycle. Urea is the major excretory substance in urine of mammals