Omveer Singh
Last Activity: 4 Years ago
Flow of energy declines as it passes from lower to higher trophic level. The energy decreases from one trophic level to the next trophic level because energy is lost as metabolic heat during transfer of energy. Hence, the pyramid of energy is always upright in any ecosystem and it cannot be inverted in a stable ecosystem. When food energy passes from producers to herbivores to carnivores, only 10% of energy is transferred from one trophic level to another trophic level.
Thus, the correct answer is 'Energy.'