Pyramids of biomass

Question 1

What do pyramids of biomass show?

Answer 1

• The biomass of each trophic level in a food chain

Question 2

What does biomass mean?

Answer 2

• The mass of living tissue that an organism is made up of
• It is the “dry mass” of the organism - doesn’t include the water in the organism

Question 3

Why do pyramids of biomass get smaller?

Answer 3

• As we go up the food chain, the biomass (collective mass) of the organisms in the trophic level is always lower than the trophic level before
• This is most of the energy between trophic levels is lost

Question 4

Why does little enegry get passed on between trophic levels?

Answer 4

• Organisms don’t usually eat every part of the of the prey
• The parts that they eat may not be absorbed as they can’t break it down properly (get excreted as faeces)
• Most of the nutrients absorbed are used to release energy through respiration (biomass is released as carbon dioxide or urea)