1. Please get out objectives #14-16 if you didn’t get them stamped last class

2. Today’s concepts for application: Food webs/food chains Trophic levels Rule of 10% Energy pyramids Biomagnification Niche vs. Habitat

3. Review with your neighbor: What is the difference between a food chain and a food web? How can the “secret of the arrows” help you figure out an organism’s trophic level? Describe the order of trophic levels on an energy pyramid. Explain the rule of 10% and why energy doesn’t just disappear.

4. Food Webs A series of interconnected food chains What would happen to the population of spiders if the insect eating birds were removed from the food web? Can you predict any other outcomes if the insect eating birds are removed?

5. Food Webs & Energy Flow: Secret of the arrows???

6. 10% Rule Only 10% of energy is available for organisms of the next trophic level. This is also why there are more organisms on the lower levels of the energy pyramid and lower numbers of top consumers. There is more energy available at the bottom of the pyramid, less at the top.

7. Your turn! Cut out the organisms, arrange them in a food web on the blue paper and glue them down. Add a human to the food web. Draw arrows between the organisms to show the direction of energy flow. On the back of the blue paper, turn your food web into an energy pyramid. Put the organisms in the right level. Write a definition of biomagnification under the web. Put a STAR next to the organism(s) most greatly affected.

8. Scenario Discuss the effects of the scenario on your ecosystem. On the blue paper, write a paragraph explaining how the scenario would most likely affect your ecosystem. Make sure everyone’s names are on the sheet!