Chapter 18 Section 3

1. Chapter 18Section 3 Energy Transfer

2. Think- Pair-Share • If some of the resources in a habitat are destroyed, which would be more likely to survive, a generalist species or a specialist species? Why?

3. Energy Flow • How do we receive our nutrients and energy? • From what we eat • Food Metabolizes and energy is transferred • As energy flows through and ecosystem is moves from Producers to Consumers. • Trophic Level- a way to organize the path at which energy flows through and ecosystem.

4. Trophic Level • It indicates an organisms position in a sequence of energy transfer. • Organized by the organisms eating behaviors. Trophic Level

5. Food Chain • Single pathway of feeding relationships among organisms in an ecosystem that results in energy transfer. • Feeding relationships are normally too complex to be represented in a single chain. Food Chains

6. Food Web • Interlinked or interrelated food chains.

7. Energy Transfer • The amount of energy stored as organic material in each trophic level in an ecosystem. • What is organic material? • Matter composed of organic compounds that has come from the remains of once-living organisms such as plants and animals and their waste products in the environment.

8. Energy Transfer • Pyramid shape represents the low percentage of energy transferred from one level to the next. • Average 10% of the total energy consumed in one level is passed on to the next level.

9. Energy Transfer • Why is the energy % transfer so low? • Some escape being eaten • Die and become food for decomposers • Even if eaten the consumer may not be able to breakdown the molecules into useful energy. • Ex: Lion eats the hoofs of antlers its prey • Energy is lost in the bodies process to metabolize the food.

10. Quiz • What is the organic material in an ecosystem called? • Biomass • What is an organism called that eats both producers and consumers? • Omnivores • How much of the total energy is transferred from one trophic level to the next? • About 10%

11. Question and Answer Time • Do you know why there are only a few trophic levels? • Because there is a low rate of energy transfer between trophic levels • There would not be enough energy to support additional trophic levels • Are there more organisms in the lower trophic level or the highest trophic level? • Lower trophic levels contain more energy • Higher trophic levels contains less energy not being able to provide enough energy to support more organisms.

12. Questions and Answer Time • Explain why food chains and food webs are more of a transfer of energy than just what eats what? • How does a food chain differ from a food web? • Explain why food chains do not exceed three or four levels? • How do producers and consumers obtain energy? • Explain why the same area can support a greater number of herbivores than carnivores? • Describe the probable effects of an ecosystem if all the plants were to die. What if all the decomposers were to die?