The following flow of energy occurs in the trophic levels in an ecosystem:

sedge → arctic hare→ arctic fox→ wolf

Which organism is located in the trophic level that contains the least amount of energy?

a. arctic fox

b. wolf

c. arctic hare

d. sedge

The answer is b. wolf.

Organisms from the higher trophic levels consume organisms from the lower trophic level. In this process, energy is lost as metabolic heat. Thus, primary producers, such as sedge, contain the greatest amount of energy originally from the sunlight. The next trophic level belongs to primary consumers, such as arctic hare, that consume primary producers resulting in less energy. Similarly, arctic fox eats arctic hare, and energy is lost again. The highest trophic level is tertiary consumers such as wolf, therefore, the wolf contains the least amount of energy.