1. Feeding Relationships

2. Give Me Energy or Give Me Death!!! (not quite Patrick Henry) All organisms need energy to live. 3 Types of Organisms –Producers –Consumers –Decomposers

3. Producers Organisms that make their own food using energy from the sun (photosynthesis) or by other means. Ex. Plants, algae, some bacteria

4. Consumers Any organism that gets its food by eating other organisms. Types of Consumers –Herbivores Plant eaters Ex. Rabbit –Carnivores Meat-eaters Eat herbivores or other carnivores Ex. Shark, wolves Scavengers: eat dead things

5. Consumers Types of Consumers –Omnivores Eat both producers and other consumers Ex. Raccoon, bears, most people

6. Decomposers Organisms that feed on the remains or wastes of other organisms. Recycle the nutrients back into the soil Often left out of food chain Ex. Bacteria and fungi

7. Food Chain Traces the path of energy as it moves from one organism to the next in an ecosystem. Shows only 1 energy path in an ecosystem. Notice how all energy begins with the SUN Producer=Photosynthesis Consumers

8. Food Chain Producer Primary Consumer Secondary Consumer Tertiary Consumer Decomposers

9. Food Chain Terminology Producer –Photosynthetic organism that gets energy from sun. Primary Consumer (1°) –First to feed. –Herbivore –Most energy gets used, some gets lost as heat, and some gets passed onto the secondary consumer. Secondary Consumer (2°) –Eats the primary consumer (herbivore) –Carnivore, omnivore, or scavenger

10. Food Chain Tertiary Consumer (3°) –Eats the 2° consumer Decomposer –Eats the remains of the consumers. –Obtains the little energy that is left from the consumers.

11. Food Web A system of several overlapping food chains. Provides a more complete picture of the flow of energy in an ecosystem. Prickly Pear Cactus Mesquite Producers First-level Consumers Second-level Consumers Third-level Consumers Desert Cottontail Woodrat Weasel Bobcat Hawk

14. Energy Flow As energy is passed from organism to organism it is used to carry out cell processes and some is lost to the environment as heat. 10% Rule –Only about 10% of the energy present at one feeding level is passed to the next feeding level. Energy Pyramid –Another way of showing the transfer of energy from one level to the next.

15. Energy Pyramids Show That the amount of available energy decreases down the food chain It takes a large number of producers to support a small number of primary consumers It takes a large number of primary consumers to support a small number of secondary consumers

16. 10% Rule & Energy Loss

17. Summary Questions Name the three energy roles of organisms in an ecosystem. How does each type of organism obtain energy? How does the amount of available energy change from one level of an energy pyramid to the next level up? Name and define the four types of consumers. What is the source of energy for most ecosystems? Why are food webs a more realistic way of portraying ecosystems than food webs?