This document discusses the structure and function of living organisms from the cellular level up. It explains that cells form tissues, tissues form organs, organs form organ systems, and organ systems work together to maintain homeostasis in the body. The document asks questions about how the structure of tissues like epithelial, connective, and muscle tissue contribute to their functions. It also asks how the structure of organs like the heart, stomach, lungs, and others contribute to their functions. Finally, it lists the 11 organ systems in the human body and instructs students to fill in which organs are part of each system.