Autotrophs = Producers Use energy from the SUN to MAKE their food Heterotrophs = Consumers Organisms that do NOT make their own food (must consume other organisms) 4 types  herbivore, omnivore, carnivore and scavenger

Food chains show how energy moves from producers to consumers Producers = bottom of the food chain! Consumers = all OTHER levels of the food chain

Arrows in a food chain indicate the direction in which energy is transferred… Berries Mice Black Bear

Energy moves from one organism to another when it is eaten Each organism in a food chain represents a feeding step or trophic level (transfer of energy) The main trophic levels are producers, consumers, and decomposers

Tertiary Consumer  eats other consumers (4 th level) Tertiary consumers = TOP PREDATORS Secondary Consumer  eats other consumers (3 rd level) Primary Consumer  eats producers (2 nd level) Producers  make their own food (1 st level)

Snake = secondary consumer Rabbit = primary consumer Grass = producer

Food webs = multiple, connected food chains All energy relationships in a community

Most organisms eat more than JUST one organism When more organisms are involved it is known as a FOOD WEB Food webs are more complex and involve many of organisms

Food chainFood web (just 1 path of energy) (all possible energy paths)

Competition = when two consumers eat the same organism Which consumers are competitors??

How many CHAINS are in this web?

Arrows point in the direction of energy transfer

Producers- Autotrophs Primary consumers- Herbivores Secondary consumers- small carnivores Tertiary consumers- top carnivores ENERGYENERGY

Energy decreases as it moves up the food chain  lost as HEAT only 10% of energy transfers to the next level

Energy Pyramids show amount of energy in each level of the food chain  less energy for higher consumers

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Biomass- the amount of organic matter comprising a group of organisms in a habitat. As you move up a food chain, both available energy and biomass decrease. Energy is transferred upwards but is diminished with each transfer.

Toxins in food chains- While energy decreases as it moves up the food chain, toxins increase in potency (strength). Toxins include pesticides, such as DDT This is called biological magnification Ex: DDT & Bald Eagles

Which trophic level has the LEAST energy available? a.Primary consumerc. producer b.Secondary consumerd. tertiary consumer Energy _______________ by ____% as you move up the food chain.