Which process is responsible for the loss of biomass at each level of the ecosystem

The correct answer is - excretion

Explanation:

In any ecosystem, there is a loss of biomass and energy at each level of the energy pyramid or trophic level. Biomass and energy both lost due to completing the life processes.

All the biomass is eaten at each level as not all food they take completely digested and removed by the process of excretion in various forms such as solid feces, carbon dioxide, and water in respiration and water and urea in urine.