Organisms are mainly composed of C, H, O & N Living organisms also contain S and P as well as several other elements These elements compose the macromolecules.
Purine pyrimidine metabolism and disorder
Ecosystems biosphere Ecosystem inputs constant input of energy energy flows through nutrients cycle nutrients can only cycle inputs energy nutrients.
The Nitrogen Cycle By: Alexander Kalogerou Chiyeung Lau Miriam Khan Charles Song.
Atoms and Elements Atoms are the basic units of all matter.