Slides in this set

Slide 1

Preview of page 1

Pyramids…read more

Slide 2

Preview of page 2

Pyramids of Number
· Each step of the pyramid
represents the number of
organisms at each trophic
· These have limits as one oak
tree can only harbour so
many insects.
· Only one oak tree, so it is
· Many insects are on the tree,
consuming it.
· Fewer woodpeckers are
needed to consume the…read more

Slide 3

Preview of page 3

Pyramids of Biomass
· These show the mass
consumed at each level,
this always decreases as
mass is lost from:
· Faeces
· Excretion
· Respiration
· Uneaten parts, e.g. bones
· A huge amount of clover
will only feed one sparrow
hawk.…read more

Slide 4

Preview of page 4

Energy transfer
· Energy is passed along the trophic levels.
· It is shown as a transfer of energy along a food chain.
· Energy is passed on up the food chain (when not used at
each level).
· Only about 10% of the energy is passed on at each level
of a food chain.
· This limits the number of trophic levels as eventually
there is not enough energy left.
· E.g. light energy is used by plants during photosynthesis.
The plant is eaten so the energy is passed to the next
organism. Etc.…read more


No comments have yet been made

Similar Biology resources:

See all Biology resources »