Solution – the flow of energy via living things in an ecosystem is known as the energy flow . All living organisms are categorized into producers and consumers . Further these producers and consumers are structured into a food chain . Every level of the food chain is known as the trophic level . The flow of energy in the ecosystem takes place through the Food Chain and Food Web . Plants are the producers and during the flow of the energy they absorb the sunlight and in the process of photosynthesis some of its part is transformed into chemical energy . At the lower trophic levels of an ecosystem there are more individuals  . There can be great length and complexity in the food chains . Each organism is eaten up the other one .

The flow of energy is unidirectional . They energy always move forward and never reverts back . It moves from prey to predator and reverses back