1. 1.Buffalos are so important to their ecosystem, that their near extinction caused a cascade effect. What type of species are they? ANS: Keystone 2. Ultimately, biodiversity is important in an ecosystem because… ANS: the greater the genetic biodiversity, the more likely species will be able to “create” genetic combinations that will allow for new adaptations in a changing environment.

2. 3. Fire ants are examples of species that were introduced to North America by accident, and without any natural predators, thrived. What type of species are they? ANS: Invasive 4.The way that humans are contributing most to the endangerment and extinction of species, is through… ANS: Habitat destruction

3. 5. What is the difference between a threatened species, and an endangered species? ANS: A threatened species is close to becoming endangered, while an endangered species is close to becoming extinct. 6.This process is the source of nearly all of Earth’s atmospheric oxygen. ANS: Photosynthesis

4. Use the following word bank and match to each of the processes below. Please note, some cycles may be used more than once, and some statements may have more than one answer. Carbon CycleRock CycleHydrologic Cycle Nitrogen CyclePhosphorus CycleSulfur Cycle 7. Associated with climate shift 8. Weathering and erosion 9. Along with Hydrologic cycle, this contributes to acid rain formation 10. Photosynthesis and Cellular respiration 11. Evapotranspiration 12. No atmospheric component 13. Fixation and ammonification ANS: Carbon cycle ANS: Rock Cycle ANS: Carbon cycle, Sulfur cycle, Nitrogen cycle ANS: Carbon cycle ANS: Hydrologic cycle ANS: Phosphorus cycle; Rock cycle ANS: Nitrogen cycle

5. 14. By far, the greatest portion of our atmosphere is this gas. ANS: Nitrogen (N 2 ) 15. How might deforestation contribute to increased CO 2 in the Earth’s atmosphere? ANS: Clearing of trees and other plants that absorb CO 2 during photosynthesis, means less of them to do that job, leaving more CO 2 in the atmosphere. 16. Which of the cycles might most be influenced if humans decreased their reliance on fossil fuels? ANS: Carbon cycle (most); sulfur cycle (slightly)

6. Use the following Earth subsystems and match them most correctly to the words or phrases below: Atmosphere LithosphereHydrosphere Cryosphere 17. Contains only H 2 0 in solid form 18. Mostly associated with the phosphorus cycle 19. Largest nitrogen sink lies here 20. All liquid, solid and gaseous water is here 21. Liquid and gaseous water may be found here 22. Infiltration occurs here 23. Evaporation occurs here 24. Heat and pressure of metamorphism occurs here 25. Most of Earth’s freshwater found here ANS: Cryosphere ANS: Lithsophere ANS: Atmosphere ANS: hydrosphere ANS: Atmpshere ANS: Lithosphere ANS: Atmosphere ANS: Lithosphere ANS: Cryosphere

7. 26. Type of rock most associated with volcanic origins is referred to as… ANS: Igneous rock 27.How might an increase in CO 2 in Earth’s atmosphere increase the pace of the hydrologic cycle? ANS: Increasing CO2 in Earth’s atmosphere means rising temperatures, causing global warming. Warmer temperatures would lead to an increase in evaporation, which in turn increases precipitation. Globally, ice sheets would melt faster, returning the water which has been locked in them for potentially millennia to the ocean.

8. 28. Give one example of a potential condensation nuclei. ANS: dust, soot and particulate matter emitted from power plants, volcanic ash, sea salt 29. Nitrogen can be returned to the atmosphere as N 2 gas through this process. ANS: denitrification 30. Nitrogen cycle process that can be accomplished by bacteria and lightning. ANS: nitrogen fixation

9. 31. When nitrogen is taken into an organism and converted into organic molecules, this process has happened. ANS: Assimilation 32. Which of the nutrient cycles contains a mostly rocky origin? ANS: Phosphorus, and sulfur 33. Currently, Earth’s oceans account for what percent of the surface? ANS: 70%

10. 34. Of all the processes within the hydrologic cycle, which works AGAINST the force of gravity? ANS: Evapotranspiration (or evaporation and transpiration) 35. What form of nitrogen is most useable by plants? ANS: Nitrates 36. Where is Earth’s largest carbon sink? ANS: Ocean water and sediments and living phytoplankton 37.Identify each of the following: NH 4 +, NO 2 -, NO 3 -, NH 3 Ammonium; Nitrite; Nitrate; Ammonia