1. Monday, September 23  Stamp for caribou graph & questions  Symbiosis warm up  8.11B notes  Limiting factors activity ***wear good shoes tomorrow for squirrel lab***

2. 8.11 B Investigate how organisms and populations in an ecosystem depend on and may compete for biotic and abiotic factors such as quantity of light, water, range of temperatures or soil composition. Vocab: biotic factors, abiotic factors, competition, limited resources, niche

3. What is an ecosystem?  The field of ecology includes plants, animals, sunlight, soil and other things.  Living and nonliving things that interact in a particular area

4. External factors affecting environment –Biotic factors are anything related to living organisms that impact another organism o Competition for resources  ex: field mouse competing with another animal for food

5. INTERACTIONS AMONG ORGANISMS Predator-prey Predator-prey An animal that hunts or kills other animals for food is called a predator. An animal that is eaten by another is called prey. Give an example of a predator-prey relationship.

6. Can you match some predator-prey relationships?

7. Predator Prey

8. External factors affecting environment  Abiotic factors are the nonliving parts that affect its survival and growth  Sunlight, temperature, shelter, water supply

9. BIOTIC ABIOTIC

10. What are the biotic and abiotic factors in this picture? Create a T chart and list them http://www.thegardenhelper.com/102902.JPG

11. biotic  Cows  Grass  Trees  Shrubs  Others unseen abiotic  Air  Water  Soil, rocks  Light  Temperature

12. niche  role of an organism in the community  how it satisfies its need for food and protection  Zebras and lions have the same habitat, the grasslands of Africa. A zebra eats grass and a lion eats meat. Thus, they have different niches.

13. competition  In a certain area, two populations may try to occupy the same niche.  Then they compete with one another.  The one that is better adapted for the niche will win and will crowd out the other population.

14. Caribou lab  List the abiotic and biotic factors in this simulation. abiotic= water & shelterbiotic= food (grass)  What happens to the caribou population during the first two years of the simulation? Due to all the resources available the caribou population increased dramatically.  What happens to the habitat (limiting factors) as the caribou population becomes too large? The amount of habitat is not able to hold the caribou population for shelter and protection from predators.

15.  What happens in the year after the population peaks? Refer to the caribou and the limiting factors in your answer. The peak is the caribou’s highest population amount. The year after its peak the caribou will drop since it used up many of its resources.  Discuss the relationship between limiting factors and the population of an organism. As resources become plentiful the number of caribou increase. As the caribou increase more resources are being used up so the resource population decreases.

16.  What are some ways that the limiting factors in the caribou habitat could change if humans begin developing the area into a housing community? Deforestation would cause less forest area for shelter and protection from predators. There would also be less grass for the caribou to eat.  What would happen to the caribou population as a result of the changes? Resources in general would become scarce causing the population to deplete. The caribou population would decline maybe even to the point of extinction.