Question

Which of the following is the first trophic level in every ecosystem?
• tertiary consumer
heterotroph
• autotroph
O primary consumer

Answer 1

Autotroph

Autotrophs (producers) form the first trophic level because they produce organic matter from inorganic sources (e.g., via photosynthesis or chemosynthesis). Heterotrophs, primary consumers, and tertiary consumers are higher-level consumers that depend on autotrophs.