Sanjana says a plant makes its own food in its leaves, from sunlight, air and water

Why

Yug's idea is the one most people held for centuries, and it isn't silly: roots really do take things from the soil — water, and small amounts of minerals the plant needs. But water and minerals are not food in the sense of supplying energy and building material. A plant makes its food (glucose, later stored as starch) in its green leaves by photosynthesis, using carbon dioxide from the air, water, and the energy of sunlight captured by chlorophyll. In the 1600s a scientist named Jan van Helmont tested this: he grew a small willow tree in a tub of carefully weighed soil for five years, giving it only water. The tree gained about 74 kg — yet the soil had lost only about 57 grams. Almost none of the tree's new mass had come out of the soil. Test: a money plant keeps growing for months in a bottle of plain water, with no soil at all. Sanjana is right: plants make their own food in their leaves by photosynthesis; the soil mainly supplies water and minerals.