Test 1A | Environmental Science | ENSC 3604, Exams of Environmental Science

Download Test 1A | Environmental Science | ENSC 3604 and more Exams Environmental Science in PDF only on Docsity! NAME: ___________________________________________ Form A ENSC 3604 –Test One – 16 September 2004 Three ( 3 ) parts -- 85 points total – 17 percent of final grade Part 1. 13 questions. 1.4615 points each. 19 total points. 1. The following statements concern aerobic respiration. Which (if any) of the first three statements is false? 1. Autotrophic organisms utilize respiration to generate energy necessary for metabolic processes. 2. Heterotrophic organisms use respiration to generate energy necessary for metabolic processes. 3. CO2 is emitted by organisms that utilize aerobic respiration. 4. Both 1 and 3 are false 5. Both 2 and 3 are false 6. Statements 1, 2, and 3 are all false 7. None of the above -- the first three statements are all true. 2. Plants remove ________ from the atmosphere and _________ from the soil environment to produce organic carbon compounds. 1. CO2 -- H2O 2. H2O -- N2 3. N2 -- H2O 4. O2 -- HCO3- 3. Considering a situation where no heterotrophs are present: which of the following is roughly equivalent to the rate at which autotrophic biomass accumulates in an ecosystem? 1. Gross primary productivity 2. Net primary productivity 3. Net community productivity 4. Respiration 4. On a per-unit area basis: In which of the following marine ecosystem types is gross primary productivity the lowest? 1. estuaries 2. coastal zones 3. upwelling zones 4. open ocean 5. Which of the following groups contains all macronutrients? 1. K, Ca, S 2. N, Fe, Cu 3. Pb, N, C 4. Fe, Zn, Cu 5. Mg, Mo, Fe 6. P, Na, Cl 7. Na, Cl, Si 6. Which of the following pairs are (a) both macronutrients, and (b) occur in seawater at very low concentrations, relative to other macronutrients that must be obtained by phytoplankton from the water column? 1. N and S 2. O2 and Si 3. P and N 4. P and S 5. Mg and Ca 6. K and Br 7. C and S 8. Na and Cl 7. Which of the three types of soil particles below is smallest? 1. sand 2. clay 3. silt 8. Which of the following occurs if carbonate minerals (such as CaCO3 and MgCO3) coming in contact with water? 1. The carbon precipitates to a solid phase 2. the water’s pH increases 3. CO2 is released 4. O2 is released 5. both 1 and 2 occur 6. Both 2 and 3 occur 9. Which of the following processes would be likely to occur in a wetland (or a swamp), but would be unlikely to occur in an oxidized environment, such as a soil near the surface on a sunny day? 1. N Ionization 2. Denitrification 3. N Mineralization 4. Ammonia volatilization 5. N fixation 10. Statements below refer to the process of nitrification. Which (if any) of the first three statements is or are false? 1. The term “nitrification” refers to transformation of N from organic to the ammonium form. 2. Nitrification requires O2 from the environment, and does not occur under anoxic (i.e., very low O2) environmental conditions. 3. Nitrification releases H+ to the environment, causing pH of the surrounding environment to decline. 4. Both 1 and 2 are false. 5 Both 2 and 3 are false. 6. Both 1 and 3 are false. 7. None of the statements are false – all are true. 11. Which of the following types of soils would have the least tendency to “fix” phosphorous. 1. a sandy soil 2. a soil high in clay 3. a soil with a high Ca content 4. a soil with a high Fe content 5. None of the above – P fixation would be highly likely in any of these soil types. 12. Which (if any) of the first 3 statements below is false? 1. P forms gaseous compounds easily under ambient environmental conditions. 2. P leaches easily from most soils. 3. “phosphate reduction” is a common process that releases HCO3- in anoxic (i.e., oxygen-poor) environments. 4. None of the above statements are true – all are false. 13. When minerals containing reduced forms of sulfur (sulfides, pyrites) are exposed to air and water at the earth’s surface, which (if any) of the following three processes does not occur commonly as a direct result? 1. H+ is released to the environment. 2. Acid-soluble metals become mobilized. 3. SO42- is produced and released to the environment. 4. None of the above – all occur commonly when sulfides and pyrite minerals are brought to the earth’s surface. 9. (3 points) Using chemical terms and/or symbols: Describe the process used commonly by human beings to produce calcium oxide (CaO). What is the significance of this process (if any) to global environmental problems? What is CaO used for? 10. (3 points) Using chemical terms and/or symbols: Describe the most common or likely fate of each of the following compounds when it is emitted into the atmosphere as a result of air pollution. (What happens to it in the atmosphere? Be sure to represent of describe any change of phase that occurs). CH4 SO2 11. (3 points) Facilities that process mining ores to produce metals such as copper, zinc, lead, nickel, and cadmium for use in manufacturing processes also produce a common air pollutant that we discussed in class. Using chemical terms and/or symbols: What is that air pollutant, and describe how processing of mining ores causes that pollutant to be emitted to the atmosphere. 12. (4 points) Nitrogen deposition is an environmental problem that helps to cause environmental pollution of water bodies throughout the world – including the Chesapeake Bay. Demonstrate your understanding of the deposition process by using chemical terms and/or symbols while answering the following questions: What is nitrogen deposition? What is one human activity that contributes to nitrogen deposition, and how does that activity cause deposition to occur? 13. (6 points) We discussed an article in class article about denitrification in a riparian wetland. On the enriched site, nitrogen came out of a home. • What was the origin of that nitrogen? • Using chemical terms and/or symbols: In what chemical form did it emerge from the home’s septic system and enter the soil? • Again using chemical terms and/or symbols: What transformation process or processes did the nitrogen undergo, and what was its fate? (what happened to the N?) (You may use an annotated diagram to answer this question, if you like) 14. (4 points) Human activity is releasing large quantities of carbon to the atmosphere via processes such as fossil fuel combustion and deforestation. For the purposes of this question, these carbon releases by human activity can be called “excess carbon.” Measurements of the atmosphere’s carbon content through time show that the atmosphere’s average carbon content is increasing. However, only about half of the excess carbon is accumulating in the atmosphere. What is happening to the rest of the excess carbon? (If it doesn’t end up in the atmosphere, where does it go?) (quick answer is ok - go to Part 3) Part III. Short Explanation Questions. 6 Questions, 24 points These questions require a bit more explanation than Part II, but you should be able to answer them correctly without writing full paragraphs. 1. (4 points) Elevated atmospheric CO2 caused by human activities is thought by many to be responsible for a warming of the earth. Referring to scientific terms and concepts discussed in class, describe the mechanism by which atmospheric CO2 is believed to cause “global warming.” (Note: do not say simply that CO2 “holds the heat” or anything like that – such an answer only repeats the question using different words, and would receive no credit). 2. (4 points) Why is the ocean so salty? (or to put the question in more technical terms: the ocean has a very high content of total dissolved solids, relative to other natural water bodies. What process or processes is responsible for the ocean’s high TDS content?) 3. (4 points) In class, we read an article about a tundra river. - what was the author’s research objective? - Describe one quantity or process that the authors measured in an effort to achieve their objective. - Referring to parts a and b of your answer above: What did the authors find? (what were their research results?) Did they achieve their objective?