* Producers: Plants and other photosynthetic organisms (like algae) are called producers. They harness the sun's energy through photosynthesis to convert sunlight, water, and carbon dioxide into glucose (sugar) and oxygen. This glucose is their food source.
* Consumers: Heterotrophs, like animals, are consumers. They obtain energy by eating producers (plants) or other consumers that have eaten producers. This means they indirectly get their energy from the sun.
* Energy Flow: The energy from the sun flows through an ecosystem in a linear fashion, starting with producers and moving up through various levels of consumers.
In essence, heterotrophs depend on the sun's energy by consuming organisms that have directly used the sun's energy for their own food production.
