Transfer of biomass
Students should be able to:
- describe pyramids of biomass
- explain how biomass is lost between the different trophic levels.
- Producers are mostly plants and algae which transfer about 1 % of the incident energy from light for photosynthesis.
- Only approximately 10 % of the biomass from each trophic level is transferred to the level above it.
- Losses of biomass are due to:
- not all the ingested material is absorbed, some is egested as faeces
- some absorbed material is lost as waste, such as carbon dioxide and water in respiration and water and urea in urine.
- Large amounts of glucose are used in respiration.
- Students should be able to calculate the efficiency of biomass transfers between trophic levels by percentages or fractions of mass.
- Students should be able to explain how this affects the number of organisms at each trophic level.
Use ratios, fractions and percentages