Food Chain and Food Web Notes
Vocabulary:
 Food Chain
o Simple model to show how matter moves through
an ecosystem
o 3-5 steps
 Food Web
o Complex model that shows ALL possible feeding
relationships in a community
The Participants:
 Producers: autotrophs that make their own food
 Consumers: heterotrophs that eat food
o Herbivores: plant eaters
o Carnivores: meat eaters
o Omnivores: plant and meat eaters
o Decomposers: eat dead organisms
o Detrivore: eat detritus (eroded matter and debris)
10% Rule:
 total energy transferred from one level to the next in
a food chain is TEN PERCENT
 other 90% released as HEAT
 10% received used for…METABOLISM
 Turning food energy into chemical energy
for cellular use
Key Components of food chains/webs
 Producers and Decomposers
 Why?
o Keep organic material cycling
o Producers: make it
o Decomposers: break it down
Sample Food Chain:
Hawks (big bird)
↓
Partridges (little bird)
↓
Grasshoppers
↓
Grass
 Therefore…
 Hawks are predators of partridges
 Partridges are predators of grasshoppers BUT prey
to hawks
 Grasshoppers are prey of partridges BUT predators
of grass