You are made of carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur, calcium, and a smattering of a few other elements (iron, zinc, etc.). Your physical self consists of just atoms and molecules, but so does a rock, or a piece of wood. And yet, unlike a rock or a piece of wood, you are a smart, thinking, remembering, feeling, emotive human being. With regard to biology, you are the very definition of:. a. trophic interactions
b. nutrient cycling
c. emergent properties
d. life-history trade-offs
e. the law of conservation of mass