THE TROPHIC PYRAMID Energy enters at the base of the food chain in the first trophic level (TL) via photosynthesis and is passed on to higher levels as consumers feed on other organisms. This is shown as a pyramid (smaller on top) because only about 10% of the energy is passed on to each subsequent level, with the other 90% being “lost” to the environment (usually as heat from the energy that the organism burns in day-to-day life before it is eaten). Most food chains have only 4 or 5 levels due to this progressive loss of energy.