Key Question: How does photosynthesis work, and why is it ...

photosynthesis works came from a simple study of plant growth. When a tiny seed grows into a massive tree, where does all its extra mass come from? More than 300 years ago, a Flemish physician named Jan van Helmont decided to fi nd out. He planted a young willow tree, with a mass of just 2 kilograms, in a pot with 90 kilograms of dry soil. He ... ................
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