Pyramid Of Numbers And Biomass

1. Pyramids of Number
A pyramid of number is a visual
representation of how many organisms
are eaten up along the food chain.
One hawk needs to eat 100 blue tits,
100 blue tits need to eat 10,000
caterpillars and 10,000 caterpillars
need to eat 100,000 leaves
“Uhh, Mr. McClure? I have a crazy
friend who says its wrong to eat meat.
Is he crazy?
Troy: Nooo, just ignorant. You see your
crazy friend never heard of "The Food
Chain".
The Simpsons - Lisa the Vegetarian
Pyramids of Number/Biomass
how much do you need to eat?
BTEC FIRST 20 October 2008
Image from the
RSPB Website
Pyramids of number don’t always look like normal pyramids. Try drawing
pyramids of number for the following food chains:
One fox eats thirty rabbits which eats 100 blades of grass
1,000,000 bacteria eat one owl which eats three hundred moths
which eat nectar from 500 plants
Pyramids of Biomass
While Pyramids of number tell us about the number of organisms involved in
a food chain, pyramids of biomass tell us about the amount of energy of each
level in the food chain. Try drawing the pyramid of biomass for the organisms
below. What would the previous examples pyramid of biomass look like?
Image from the
RSPB Website