The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, terrestrial, and marine ecosystems. ... Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification.
<em>The answer is endoplasmic reticulum</em>
Starvation.
Disease.
Weather.
Lack of mate.
Offspring dying.
Hunting.<span />
