Why is only a small part of the biomass eaten by a herbivore used to make new tissue?
Most of the food is used to keep the animal warm and the rest is lost in faeces.
Some of the food is not eaten and the rest is broken down by decomposers in the gut.
Most of the food is changed into urea, which is then stored in the body of the animal.
Some of the food is not absorbed and much of what is absorbed is used in respiration.
61 exam-style questions on AQA GCSE Biology 7.4 Trophic levels in an ecosystem, covering 7.4.1 Trophic levels, 7.4.2 Pyramids of biomass, and 7.4.3 Transfer of biomass. Each one has a worked solution and a mark scheme showing where the marks go.