Understand the essential role of oxygen, water, and food molecules in the chemical reactions of human cells.
Identify carbon dioxide and urea as waste products requiring removal from the body.
Explain how moving substances into, around, and out of the body relies on the interaction between the circulatory, gaseous exchange, digestive, and excretory systems.
Understand how exchange surfaces increase the surface area to volume ratio to sustain living cells in multicellular organisms.
