photosynthesis
Plants and trees from Iconographic encyclopaedia of science, literature, and art.
Trophic Relationships in the Marine Environment
All living things need energy to survive and thrive. Ultimately, all food energy starts with the sun (or, rarely, deep sea hydrothermal vents). Plants make their own food, through photosynthesis, from the energy of the sun. Things eat plants, and other things eat the things that eat the plants. And so on.
