Memory Anchor:

• Super Challenge:

  Stretch:

  Challenge:

Key Questions:

1. What do pyramids of biomass represent and where can trophic level 1 be found?
   • Pyramids of biomass can be constructed to represent the relative amount of biomass in each level of a food chain. Trophic level 1 is at the bottom of the pyramid.
2. What is the shape of a pyramid of biomass?
   • A pyramid of biomass is large at the bottom and narrower at the top.
3. How is biomass lost between different trophic levels?
   • Biomass is lost at each trophic level through not being digested, being excreted or being used as Energy by the organism.
4. Name examples of producers.
   • Producers are mostly plants and algae which transfer about 1 % of the incident Energy from light for photosynthesis.
5. What % of biomass is transferred up each trophic level?
   • Only approximately 10 % of the biomass is transferred up each trophic level.
6. What are losses of biomass due to?
   • 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.
7. What is used in respiration?
   • Large amounts of glucose are used in respiration
8. If the producer trophic level has 4200J of energy and the primary consumer has 800J what is the efficiency of transfer between these trophic levels?
   • 800J/4200J = 0.19 Which is 19%
9. How can the efficiency of biomass transfers between trophic levels be calculated?
   • To calculate the efficiency of biomass transfers between trophic levels, percentages or fractions of mass must be used.
10. How does lost biomass affect the amount of organisms at each trophic level?
    • The loss of biomass means that the number of organisms decrease at each trophic level as the amount of Energy passed on between the trophic levels decreases.