2 concepts
Nitrogenous Waste in Terrestrial Animals: The Urea Cycle
Urea, a nitrogenous waste material, is the end product excreted in urine when ammonia is metabolized by animals, such as mammals.
Nitrogenous Waste in Birds and Reptiles: Uric Acid
Birds and reptiles have evolved the ability to convert toxic ammonia into uric acid or guanine rather than urea.