4.5(a&b) Food Chains and Food Webs

4.5a Food Chains 



Food Chains link together:
Producer ----> Primary Consumer ------> Secondary Consumer -----> Tertiary Consumer

• Only one organism per trophic level
• You cannot show an organism being an omnivore / cannot show organisms feeding at more than 2 trophic levels
• Food Chains show the flow of matter and flow of energy

4.5b Food Webs




The food web allows us to provide a better description of the ecosystem (ecosystems are community of organisms interacting) In this case interacting = feeding

Feeding at different trophic levels:
consequences
- organisms can have multiple predators
- may be feeding on multiple pray
- resulting to the food chains becoming linked.

4.4 Trophic Levels

- Tropic = feed
- In the example:

• the carrot plant is doing the photosynthesis - - - - - in ecology terms - - - - - Producer (light energy and turning it into chemical energy)
• the carrot fly is eating the plant = herbivore - - - - - in ecology terms - - - - - Primary Consumer (chemical energy of the plant into chemical energy of the fly - change in the form of the chemical energy)
• the flycatcher eats the fly = carnivore - - - - - in ecology terms - - - - - Secondary Consumer (again, changing the chemical energy from one form to another)
• another carnivore eating another carnivore = top carnivore. - - - - - in ecology terms - - - - - Tertiary Consumer (Chemical energy from one form to another)

At some stage, they all die.

At this point, decomposers break the complex molecules down into nitrates and phosphates. 

fungi and bacteria are an example of decomposers.