B3 - Pyramids of Biomass and Number Flashcards
What decreases as you move up a trophic level?
The amount of biomass
What model can we use to show how biomass changes?
Pyramids of biomass
Give an example of a food chain starting with a rose bush
2000g of rose bush, feeds 80g of caterpillars, which feeds 20g of birds.
What does each bar on a pyramid of biomass show?
The mass of living material at that stage of the food chain, basically how much all the organisms at each level would weigh if you put them all together.
What goes on the bottom of a pyramid of biomass?
The producer, because it’s the bottom of the food chain.
What do the different levels of the pyramid of biomass show?
Bottom level - producers
Then primary consumers, then secondary consumers etc
Why are biomass pyramids a pyramid shape?
Because biomass is lost at each stage of the food chain.
Why is it some times difficult to construct and accurate pyramid of biomass?
Because some organism feed at more than one trophic level.
In a pyramid of numbers what does a bar show?
The number of organisms at that stage of the food chain.
Which type of pyramid can be different shapes?
Pyramid of numbers
See page 49 for question. (2 marks)
B because the bar for the producer is smaller than for the primary consumers (1 mark) and just one tree or large plant can feed many consumers (1 mark).
