What is a Toxic Metabolic Waste Product Formed Primarily by the Breakdown

Question

What is a toxic metabolic waste product formed primarily by the breakdown of proteins?  
A) Kidney stones
B) Ammonia
C) Nephridia
D) Uric acid
E) Protonephridia

Accepted Answer

Ammonia is a toxic metabolic waste product formed primarily by the breakdown of proteins. It is converted to less toxic substances like urea or uric acid in many organisms for excretion.