1. circulatory system, artery–vein–capillary identification, blood transport of oxygen, nutrients and waste, role of lungs and organs in exchange 2. food web structure, sun as energy source, food chain construction, bioaccumulation of toxins, higher concentration at top trophic levels 3. dissolving model, interaction of solid-liquid particles, temperature increase effects (particle speed, spacing), phase behavior without vaporization 4. bacterial growth variables (bacteria/nutrient control), acid concentration effects, laboratory safety (risks and mitigation), stomach acid as natural defense 5. thermometers and temperature reading, boiling/melting point concept, substance suitability (ethanol, mercury, gallium), state of matter requirement 6. floating and sinking principles, material density and buoyancy percentage, modeling clay shaping for floatation, refraction of light in water, rock classification (igneous/sedimentary), gas diffusion and conservation in sealed systems