What are the three main types of nitrogen wastes excreted by living beings?
The major nitrogen wastes excreted by living beings are ammonia, uric acid and urea. Living beings that secrete ammonia are called as ammoniotelic. Creatures that secrete uric acid are called as uricotelic. Organisms that secrete urea are called ureotelic.
The Excretory System - Image Diversity: ammonia molecule uric acid molecule urea molecule