UPSC CDS 2 2021 GK Paper

Energy in the form of food decreases as it moves up trophic levels in food chain because 90% energy is lost as metabolic heat on each trophic level as organisms from one trophic level are consumed by organisms from the next level. Trophic Level Transfer Efficiency (TLTE) measures the amount of energy that is transferred between trophic levels. Thus, decrease in the available energy at higher trophic levels limits the number of trophic levels in a food chain available.