Question

Which form of nitrogenous waste is most toxic?

• A. Urea
• B. Ammonia
• C. Uric acid
• D. All are non-toxic

Answer 1

The correct option is B Ammonia

The nitrogen compounds through which excess nitrogen is eliminated from organisms are called nitrogenous wastes. They are ammonia, urea, uric acid and creatinine. All of these nitrogenous wastes are produced from protein metabolism.
Among these nitrogenous wastes, ammonia is the most toxic form of nitrogenous waste. Urea is less toxic than ammonia and more toxic than uric acid. Uric acid is the least toxic.