1) Energy from the sun powers photosynthesis in green plants, which convert carbon dioxide, water, and sunlight into glucose.
2) This chemical energy from glucose is transferred through ecosystems as organisms eat each other, forming food chains.
3) Producers like plants capture energy from the sun which is then consumed by primary consumers like herbivores, and passed up through secondary and tertiary consumers in a trophic pyramid, with decomposers recycling nutrients.