What is the primary nitrogenous excretion product of adult amphibians and terrestrial mammals?

💡 Solution & Explanation

Adult amphibians and terrestrial mammals excrete nitrogenous waste primarily as urea, earning them the classification of ureotelic animals because urea requires less water for elimination than ammonia. Aquatic animals typically excrete ammonia, whereas birds and reptiles excrete uric acid to conserve body water. Urea is synthesized in the liver through the ornithine cycle and subsequently filtered out by the kidneys.