When a plant or animal dies, or an animal expels waste, the initial form of nitrogen is organic.

Through the cord, the fetus receives nourishment and oxygen and expels waste.

It's little more than a hollow tube that takes food in at one end and expels waste at the other.

They have a central cavity that serves to both take in food and expel waste.

When a bacterium dies, or expels halogenated waste, water exposure and oxidation may extract them as acids: HF, HCl, HBr.

I would almost conclude that a massive fleet of starships moved through here, expelling waste as they went, except we know that did not occur.

Its function is to expel solid and gaseous waste from the gastrointestinal tract.