**you will learn what these mean and how to use them** Food web; food chain; predator; prey; producer; consumer; decomposer; herbivore; carnivore; omnivore; trophic levels; first level; second level; 10% rule

The participants: Predator: an organism which preys upon other organisms Prey: the animal being hunted; organism being eaten

The participants (continued) Producer (autotroph) – an organism that makes its own food and stores energy Consumer (Heterotroph) – an organism that obtains food and energy by eating other organisms

Types of Consumers: 1. Herbivores – organisms that eat only plants Example: cattle 2. Carnivores – organisms that eat only animals Example: coyotes 3. Omnivores – organisms that eat both plants and animals Example:bears

Types of Consumers (continued) Decomposer (also a heterotroph) – organisms that obtain energy by breaking down wastes and the remains of dead organisms. –Ex: mushrooms and earthworms

What do these make up? Food Web – model that shows how energy (matter) passes from one organism to another. *More accurate than a food chain because they show ALL the feeding relationships within an ecosystem.

What do these make up? (continued) In a food chain, an arrow points from the organism being eaten to the organism doing the eating. **The direction the energy is flowing** Primary source of energy in a food chain is the sun.

Sample Food Chain: Hawks (big bird)  Therefore… Partridges (small bird)Hawks are predators of partridges. Partridges are predators of grasshoppers BUT prey to hawks. Grasshoppers Grasshoppers are prey of partridges BUT predators of grass. Grass

Trophic level of consumer First (primary) level: Consumers that eat producers Second (secondary) level: Consumers that eat first-level consumers **Continues onto 3 rd (tertiary) consumers**

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

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

10% Rule:  Total energy transferred from one level to the next in a food chain is TEN PERCENT  other 90% released as HEAT; used to support the life processes (keeping warm, breaking down food, etc) of the primary consumer.

10 % rule (continued):  10% received is used for…METABOLISM Turning food energy into chemical energy for cellular use.

10% rule (continued) * This means that the higher the level of consumer, the fewer there are of them because they have to eat A LOT to get enough energy.