Honors Biology – Unit 1 Review Ecology 1. Describe what is meant by an organism’s niche. Give an example. What is likely to happen if two organisms try to occupy the same niche? 2. Define the word Ecology. 3. Understand and know how to use a food chain. How is a food chain different than a food web? In a food chain, if the second level consumer suddenly becomes extinct, what would likely happen to the producer in that food chain. 4. What organisms are the most important part of the nitrogen cycle? What do they do? 5. What is the difference between how energy moves through an ecosystem and how materials move through an ecosystem? 6. Describe the difference between abiotic and biotic factors. 7. What is the “biosphere”. 8. In any type of trophic relationship, what level of organism contains the most energy? Which level contains the most biomass? Why is this necessary? 9. What roll do decomposers play in an ecosystem? Where do they occur in the food chain or food web? 10. Why aren’t there normally a large number of predators that exist at the top of a food chain? 11. How much energy is lost as it moves from one trophic level to the next? What becomes of that lost energy? Where does it go? 12. What is the difference between a nitrifying bacteria and denitrifying bacteria? 13. Why do ecosystems go through a process of succession? 14. What types of organisms are the pioneer organisms that can establish new ecosystems? Why do they have to be first? What do we call the “final stage” of an ecosystem’s development? 15. What is meant by the term “symbiotic relationship”? 16. Describe the different types of symbiotic relationships.