The relationship of organisms working in a food chain can be described as “FLOW OF ENERGY”. It is from producers to consumers to decomposers. Each group depends on each other for food and energy.

They will not be able to survive if one group were removed. In general, the flow of energy in an ecosystem starts with sunlight (the ultimate source of all energy on Earth) which is absorbed by the producers, goes to the consumers, then to the decomposers, and back to the producers to start all over again.