7.4.2: Pyramids of biomass
Not started yet — this one needs some love.
Pyramids of biomass represent the relative amount of biomass in each level of a food chain.
Trophic level 1 is at the bottom of the pyramid.
A correct pyramid of biomass uses bars drawn to scale from suitable biomass data.
The producer bar belongs at the bottom, even if the food chain is written left to right.
Common exam mistakes
Do not draw a pyramid of numbers when the question asks for a pyramid of biomass; use biomass values, not organism counts.
Do not make bars decorative or roughly pyramid-shaped; each bar should match the biomass value given in the data.
Do not reverse the trophic levels when turning a food chain into a pyramid; start with trophic level 1 at the bottom.
Check units and scale before drawing; a biomass pyramid can be inaccessible if the bar widths are not calculated from the data.