Question

Depict a food chain by placing the following organisms in the correct trophic levels. Grass, Grasshopper, Frog, Snake, Eagle.

Answer 1

Hint: Ecologists assign every organism of a community a trophic level or feeding level, depending on what it eats. A food chain shows how the organisms are related to each other by the food they eat.

Complete answer:
In an ecosystem, autotrophs are the only organisms that can produce all the biological molecules they need for their growth from non-living substances utilizing radiant energy, they are called primary producers. Heterotrophs on the other hand, are unable to utilise energy for the synthesis of food, obtain their energy and carbon and several other atoms by consuming autotrophs and other heterotrophs. Therefore, they are called consumers of an ecosystem.
Thus, in a typical terrestrial ecosystem plants (producers) are eaten by herbivorous animals (primary consumers). These animals may in turn be eaten by another animal and in this way energy is transferred from one organism to another, each feeding on the preceding organism and providing raw materials and energy for the next organism. This series or sequence is known as the food chain.
Grass is the primary producer which is eaten by Grasshopper (primary consumer). The primary consumers efficiently digest plant matter for energy and serve as ecological links between the producers and other trophic levels. At the next trophic level are the carnivores, i.e. frogs that consume the herbivores. Snake is also a carnivore which eats frogs. Further, are the tertiary consumers, they are also the carnivores who eat other carnivores. Snakes are eaten by eagles . Eagles constitute the top carnivores which occupy the terminal end of the food chain and are not eaten by other animals.
Grass → Grasshopper → Frog → Snake → Eagle

Note:
In an ecosystem, as energy travels from one trophic level to the next, a major amount of energy is lost as heat ($90\%$) and only about $10\%$ is passed on to the next level of consumer.