Ace the DAT Ecology Exam 2026 – Unlock Your Inner Eco-Warrior!

Ecological efficiency describes the proportion of energy that is transferred to the next trophic level. When energy moves from one level to the next, organisms use much of it for metabolism, maintenance, and life processes, and some is lost as heat or remains unavailable due to digestion or unconsumed biomass. Because only a portion makes it to the next level, the energy transfer is typically a small fraction—often around 10%—which is why energy pyramids slope upward from producers to apex consumers. The other terms refer to different ideas: ecological pyramids are diagrams showing energy or biomass at each level, while the hydrologic cycle and carbon cycle describe the movement of water and carbon through ecosystems, not the efficiency of energy transfer between levels.