Praxis II: Biology Content Knowledge Exam Prep

Answer: C, If the producers make 10⁹ kcal of energy, 10⁶ kcal of energy will be available for tertiary consumers. The tertiary consumers are three trophic levels up from the producers.

Key Takeaway: In an ecosystem, energy flows up from the producers up to the consumers. The primary consumers are those that feed directly on the producers. The secondary producers feed directly on the primary consumers, and so forth. Since the amount of energy available decreases with each increasing trophic level, the energy pyramid also serves as a biomass period that indicates the number of individuals on each trophic level.