Final answer:
Energy is lost between trophic levels because of metabolic processes and the physical law that dictates energy conversion leads to a loss in the form of heat, resulting in lower energy transfer efficiency and limiting trophic levels in a food chain.
Step-by-step explanation:
Energy is lost when moving from a lower trophic level to a higher trophic level due to the second law of thermodynamics, which leads to a decrease in energy because it is converted to heat and results in increased entropy. The trophic level transfer efficiency (TLTE) is low, typically around 10 percent. Therefore, organisms at each level use approximately 90 percent of the energy for metabolism, growth, repair, and as heat dissipated to the environment.
Additionally, some energy is lost as waste or incompletely digested food. This loss of energy limits the length of the food chain and why there are generally no more than four or five trophic levels. Each successive level has less energy available and often fewer organisms and less biomass.