Oxygen cycle The cycling of oxygen between the biotic and abiotic components of the environment (see biogeochemical cycle). ... In the process of respiration oxygen is taken in by living organisms and released into the atmosphere, combined with carbon, in the form of carbon dioxide.
Hormones are transported through the blood stream to target cells.
No animals get nitrogen from eating plants or other animals that contain nitrogen and plants get nitrogen from the soil by absorption through their roots as amino acids, nitrate ions, nitrite ions, or ammonium ions.
A. they divide in two
i dont know b sorry
