Final answer:
The flow of energy through an ecosystem starts with the sun, which provides energy in the form of sunlight. This energy is captured by producers through photosynthesis and passed on to higher trophic levels through consumption.
Step-by-step explanation:
The flow of energy through an ecosystem starts with the sun, which provides energy in the form of sunlight. This energy is captured by producers, such as plants, through photosynthesis, and is converted into glucose. Producers are then eaten by herbivores, which are in turn eaten by carnivores. The energy flows from one trophic level to another, with energy decreasing as it moves up the food chain. Overall, the sun is the original source of energy in an ecosystem, and it is gradually transformed and transferred from one organism to another.