Give three reasons for why biomass may not be transferred from primary consumers to organisms at higher trophic levels in the food chain. [3 marks]

Some energy is lost via the the primary organism's waste products (such as urine and faeces).Some energy is lost as heat produced as a product of respiration.Energy produced by respiration may be used for movement, reproduction etcTherefore not all energy will be converted into biomass or transferred to the next trophic level.
Do not mention:'Not all energy from the sun is converted via photosynthesis by plants into biomass.' The question specifies energy transfer between primary consumers and higher trophic levels. This mark point is only relevant when primary producers are involved in the question.