In a certain ecosystem, caterpillars eat grass. Field mice eat the caterpillars and seeds from the grass. Snakes eat the mice. Hawks eat both the snakes and mice. Such an arrangement would be considered a(n)

A) food web.
B) food chain.
C) ecosystem.
D) first trophic level.
E) second trophic level.

This is a food web because it shows the interconnected pathways of energy flow among different organisms in the ecosystem, including multiple food chains (grass -> caterpillars -> mice -> snakes -> hawks). A food chain only shows the linear pathway of energy flow between one trophic level and another. An ecosystem refers to the community of living organisms and their interaction with the physical environment. The terms "first trophic level" and "second trophic level" refer to the positions of organisms in the food chain/web, with primary producers being at the first trophic level and top carnivores being at the higher levels.