Animals excrete various forms of nitrogenous [ny-TROJ-un-nuhs] wastes that are mainly the result of the catabolism of which of the following?

W) Cellulose and triglycerides [try-GLIS-uh-ryds]

X) Proteins and nucleic acids

Y) Glycolipids and glycerol

Z) Starches and proteins
X) PROTEINS AND NUCLEIC ACIDS