1.  Friday Dec. 11 Today’s Bellwork: 1)Submit your yeast lab conclusions to class inbox folder a.Do NOT approach me with excuses/reasons why you don’t have it completed. 2)Finish completing your Rabbits vs. Wolves activity a.Graphs & questions at least through simulation #4 and b.the VOCABULARY i.Use textbook if necessary

2. Agenda 1) Population Density Problems – on board 2) Debrief Rabbits vs. Wolves 3) Introduce Trophic Cascades Quiz on populations on block day next week – vocabulary important!!

3. Population Vocab

4. Predator/Prey Relationships

5. Simulation 1

6. Carrying Capacity Graph of a rabbit population in a field. Populations at carrying capacity fluctuate around line. Carrying capacity is their average population over time. What causes populations to fluctuate?

7. Simulation 3-5 1) Excessive rabbit population—what eventually happened? 2) Excessive wolf starting population—what eventually happened? 3) Perfect Balance challenge– what parameters were changed? How realistic were those changes; could they happen in nature?

8. Predator/Prey Relationships 1. How do the relationships between predator, prey, & producers affect an ecosystem? 2. Can any one species have an advantage? If so, what happens? Discuss in your groups, and write a clear & concise answer to each question on the paper provided.

9. Trophic Cascade Occurs when predators in a food web lower the population, or alter the behavior of, their prey. Has a “cascade” effect on lower trophic levels and the ecosystem as a whole. Some species are affected directly, some indirectly Some species may benefit, some may not. The food web is changed New Vocabulary Apex predator - top member of the food chain/biomass pyramid Browser -eats elevated trees & bushes (branches, leaves, etc.) Grazer -eats grass

10. Trophic Cascade Example: Reintroduction of gray wolves to Yellowstone National Park in 1995

11. Trophic Cascade

13. Environmental Update  Paris Climate Talks 2015 Paris Climate Talks 2015