1. Food Chains
Shows the steps of energy transfer within an ecosystem. Each step is called a trophic level.

2. Abiotic vs. Biotic
Factors in a food chain and an ecosystem can be either abiotic or biotic.
Biotic: living (or once-living)
Animals, plants, dead organic matter
Abiotic: non-living (was never alive)
Sun, water, air, soil acidity, pollution, etc.

3. ALL FOOD CHAINS START WITH ENERGY FROM THE SUN
Is the sun a biotic or an abiotic factor?

4. Key Terms
Producer: Anything that can make it’s own energy through photosynthesis (mostly plants)
Producers are also called “Autotrophs”
“Auto” = self and “Troph” = energy, so they make energy for themselves
Consumer: Anything that must eat it’s food to get energy
Primary Consumers eat the producers
Whatever eats the primary consumer is called the secondary consumer
Whatever eats the secondary consumer is called the tertiary consumer
Consumers are also called “Heterotrophs”
“Hetero” = different and “troph” = energy, so they get their energy from different sources

5. Decomposers: organisms that obtain their energy by breaking down dead organic matter (anything that was alive….leaves, animals, etc.) and returning it to the soil
Example: Fungi
Decomposers are a type of heterotroph because they still rely on other sources of food for their energy

6. Food Webs
A network of complex interactions formed by the feeding relationships among various organisms in an ecosystem
AKA: a bunch of food chains joined together to show all the possible food chains possible in an ecosystem