Food Chain & Web Biology Notes PDF

***[Food chain/Web]*** ***Food chain: A food chain shows the pathway of energy and material flow through a specific ecosystem. Most organisms occupy a trophic level in more than one food chain.*** ***Food web: Shows the relationship between many food chains.*** ***[Ecological Niche:]*** **➜*Any...

***[Food chain/Web]*** ***Food chain: A food chain shows the pathway of energy and material flow through a specific ecosystem. Most organisms occupy a trophic level in more than one food chain.*** ***Food web: Shows the relationship between many food chains.*** ***[Ecological Niche:]*** **➜*Any organism that cannot photosynthesize (create their own food)*** ***is called a consumer. Consumers include herbivores, carnivores,*** ***omnivores, scavengers, and detritivores*** ***Ecological niche: The role of an*** ***organism in its ecosystem. Includes what*** ***the organism eats, what eats it, and how it behaves.*** ***[Pyramid of Energy: ]*** **➜*About 10% of the*** ***energy is passed on to*** ***the next trophic level*** **➜*Energy is lost as*** ***thermal energy or used*** ***for biological*** ***processes (ex. growth)*** **➜*Always decreases in*** ***size from bottom up*** ***since higher trophic*** ***levels always have*** ***less energy available*** ***to them*** ***[Pyramid of numbers:]*** **➜Shows the number of** **individuals of all** **populations in each** **trophic level** **➜May either increase or** **decrease in size from** **bottom up** ***[Pyramid of biomass:]*** **➜Shows the total mass** **of organisms in each** **trophic level** **➜May either increase or** **decrease in size from** **bottom up** **[Bioaccumulation]: The tendency for toxic substances to** **accumulate in organisms as they progress** **up the food chain/web. Common with pesticides and heavy metals such as mercury. Substances bioaccumulate because they are not soluble in water but rather are** **soluble in fats and oils; therefore they are not excreted.**