matter
All living things are made of matter . In fact, matter is the stuff of which all organisms are made. Anything that occupies space and has mass is known as matter. Matter, in turn, consists of chemical substances. It is the carbons, hydrogens, oxygens and other elements that combine to form molecules, compounds, organelles, cells and eventually tissues, organs and organisms. In addition to being made of matter, all living organisms also need energy to survive.