[Assess students' understanding of how photosynthesis and cellular respiration connect to drive energy flow in ecosystems. Scope includes roles of producers and consumers; inputs and outputs (sunlight, CO2, O2, glucose, ATP); simplified equations; energy transfer across trophic levels and loss as heat; and interpreting diagrams, food chains, or simple O2/CO2 data. Items may ask students to explain and compare processes, trace flow of energy and matter, and predict consequences of changes in producers or light availability.]