4.1 Roles of living things Everything needs energy to live and survive Organisms of most ecosystems gather food in three basic ways. All energy enters at the level of the producer 1.Producers 2.Consumers 3.Decomposers

1. Producers  O rganisms that make their own food from inorganic molecules and energy  Plants are most common. They photosynthesize. They are mainly terrestrial (on land) *Small protists and some bacteria are common. They are mainly aquatic ( in water)

2. Consumers   O rganisms that cannot make their own food *A ll animals *A ll fungi *S ome protists *S ome bacteria *Obtain energy by eating other organisms

4 Types of Consumers I. Herbivores II. Carnivores III. Omnivores IV. Scavengers

I. Herbivores *Only eat plants *Since they only eat plants they are called primary consumers *Many insects, birds and grazing animals

II. Carnivores *Eat herbivores or other carnivores *If eat herbivores, called secondary consumers *If eat other carnivores, called tertiary consumers *Lions, snakes, hawks, spiders

III. Omnivores *Eat both producers and consumers *Includes humans, bears and chimps *Fit all 3 categories of consumers  P rimary:eat potato  S econdary:eat hamburger *Tertiary:eat snake

Omnivores

IV. Scavengers *Feed on bodies of dead organisms. Do not hunt. Also feed on dead plants *Vultures and hyenas

3. Decomposers *B acteria and fungi that consume the bodies of dead organisms and other organic wastes. *They break down the organic waste matter. Crucial to ecosystem because they recycle the nutrients back into the environment.

Trophic Levels *D ifferent feeding levels of organisms *A layer in the structure of feeding relationships

Trophic Levels * 1 st trophic level are producers *2 nd, 3 rd, 4 th, and 5 th trophic levels are consumers

Autotrophs Producers which make their own food

Heterotroph s Consumers which obtain their nourishment by eating other organisms