Photosynthesis rate – light, CO₂, temperature and the compensation point

BiologyPlant PhysiologyAges 16–17

A sprig of aquatic pondweed (Hydrilla) in a beaker of water under a lamp releases O₂ bubbles faster or slower depending on light intensity, CO₂ concentration and temperature; switching off the lamp leaves the plant only respiring, releasing CO₂. A graph plots gross photosynthesis, respiration and net photosynthesis against the chosen variable, marking the light compensation point and the light saturation point, while students drag sliders and switch the lamp on or off directly in the simulation.