Learning Objectives Identify the source of energy for life processes Trace the flow of energy through living systems

Energy Flow All living things need energy to survive

Sunlight Sunlight is the main energy source for life on Earth

Organisms are divided on how they obtain energy Do Not Write Organisms are divided on how they obtain energy Autotrophs Heterotrophs

Autotrophs Autotrophs - make their own food for energy using sunlight or chemicals. AKA producers

Heterotrophs Heterotrophs - organisms that rely on other organisms for their energy and food supply. AKA consumers

Herbivore Herbivore - Eats only plants. Examples: deer, squirrel

Carnivore Carnivore - eats other animals Example: Tiger, Hawk

Omnivore Omnivore - eats plants and animals Examples: Humans, Bears

Detritivores Detritivores - feeds on the bodies of dead matter Decomposers - break down organic matter Scavengers - feed on dead/dying animals

Tertiary consumer Secondary consumer Primary consumer Producer Do Not Write Tertiary consumer Secondary consumer Primary consumer Producer

Three ways to illustrate energy flow: Do Not Write Energy Paths Three ways to illustrate energy flow: Food Chain Food Web Food (Energy) Pyramid

Food Chain A food chain shows the path of energy from one organism to the next. Arrow points in the direction that the energy is flowing

Food Web A food web shows all feeding relationships in an ecosystem (network of many food chains)

Food (Energy) Pyramid A level of the food pyramid is called a trophic level Food chains/webs can be shown as a food pyramid. Producers at bottom, consumers at upper levels

Trophic Levels Energy is lost with each trophic level ~ 90% is released to the environment as heat ~ 10% of the energy is used by organisms

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