Ch3 Ecosystems What Are They And How Do Test Bank + Answers

CHAPTER 3—ECOSYSTEMS: WHAT ARE THEY AND HOW DO THEY WORK?

MULTIPLE CHOICE

1. Scientists estimate that tropical rain forests contain up to half of the earth’s land plants and animal species. What percentage of the world’s land surface do tropical rain forests cover?

2. The disappearance of the tropical rain forests is an important issue because it will ____.

3. The oceans of the earth cover approximately what percentage of the earth’s surface?

4. All physical forms of water (solid, liquid, and gas) on or near the earth’s surface make up the ____.

5. What is the term for the portion of the earth's atmosphere, hydrosphere, and geosphere where life is found?

6. High quality energy is constantly ____.

7. Life on the earth depends on interaction of gravity, the cycling of matter, and the ____.

8. Ozone gas in the lower part of the stratosphere filters out how much of the sun’s harmful ultraviolet (UV) radiation?

9. What is the innermost layer of the atmosphere, extending 17 kilometers above sea level at the tropics and about 7 kilometers above the earth’s north and south poles?

10. Fossil fuels and minerals are found in the ____.

11. Which statement about microorganisms is true?

12. Which of the following is a major violator of the chemical cycling principle?

13. What is an end product of anaerobic respiration?

14. Ecology is the study of ____.

15. Aerobic respiration requires ____.

16. Which of the following is an abiotic component of an ecosystem?

17. What term describes groups of different species living together in a particular place with a potential for interacting with one another?

18. Which consumers feed on the flesh of herbivores?

19. Organisms that feed only on plants are called ____.

20. The very necessary process of breaking down the dead bodies of organisms is a function of ____.

21. What term describes organisms that complete the final breakdown and recycling of organic materials from the remains of all organisms?

22. The most fundamental structural and functional units of life are ____.

23. Complex networks of interconnected food chains are ____.

24. Each trophic level in a food chain or food web contains a certain amount of organic matter, called ____.

25. The typical percentage of high quality energy loss in transfers from one trophic level to the next is about ____.

26. Despite a low net primary productivity (NPP), which ecosystem or life zone produces the most biomass each year?

27. Vitousek, Rojstaczer, and others estimate humans now use, waste, or destroy what percentage of the earth's total potential NPP?

28. Which terrestrial ecosystem or life zone produces the highest net primary productivity per year?

29. Which terrestrial ecosystem or life zone produces the lowest net primary productivity per year?

30. If grass stores 1,000 energy units received from the sun, the ecological efficiency of the ecosystem is 10%, and the trophic levels are grass  cow  human, how many units of energy does the human receive of the original 1,000 units?

31. What is a major difference between the phosphorus cycle and the water, carbon, and nitrogen cycles?

32. What is a result of phosphate rich runoff from land?

33. Much of the earth's sulfur is stored in

34. Hydrogen sulfide and sulfur dioxide are added to the atmosphere by ____.

35. Humans add sulfur to the atmosphere primarily by the release of ____.

36. The hydrologic cycle is the movement of ____.

37. How much of the earth's water supply is available as accessible liquid freshwater?

38. The hydrologic cycle is driven primarily by ____.

39. What refers to the conversion of water from liquid to vapor from the earth’s oceans, lakes, rivers, and soil?

40. Most precipitation falling on terrestrial ecosystems becomes ____.

41. Carbon is a major component of ____.

42. Humans intervene in the nitrogen cycle in several ways. Which of the following is one of those ways?

43. Ammonia that is not taken up by plants may undergo ____.

44. The form of nitrogen used by plants to produce various amino acids, proteins, nucleic acids, and vitamins is ____.

45. Which statement about water is true?

46. What is one major way in which humans harmfully impact the water cycle?

47. What is a primary link between photosynthesis and aerobic respiration?

48. Scientists have less than ____ percent of the ecological data they need to evaluate the ecosystems in the United States.

49. Ecological tipping points related to the earth’s major natural systems are also called

50. The use of transmitters and GPS systems are very important in the study of ____.

1. Although tropical rain forests are only about 2% of the earth's land surface, they contain about 50% of the world's land plant and animal species.

2. Methane, CO₂, and water vapor make up about 30% of the earth's troposphere.

3. While the troposphere is 11 miles thick above sea level at the tropics, it is only four miles thick above the North and South poles.

4. The hydrosphere is the earth’s intensely hot core, thick mantle composed mostly of rock, and thin outer crust.

5. A group of different species living in a particular place, and potentially interacting with each other is called a population.

6. Thanks to concentrated efforts, nearly half of the waste produced by humans is now recycled.

7. Transfer of energy through food chains or webs is very efficient, making a lot of energy available to organisms.

8. The reason we observe a "pyramid" of energy flow instead of an energy flow "cube" is because the low ecological efficiency of biological systems limits the numbers of organism in the higher trophic levels.

9. Gross primary productivity (GPP) is the biomass produced by photosynthesis minus the rate at which biomass is used for aerobic respiration.

10. Nitrogen gas, the major component of the atmosphere, cannot directly be used by plants and animals.

11. Over land, most water that reaches the atmosphere comes from transpiration.

12. Because carbon makes up such a small amount of the earth’s atmosphere, even a small change, caused by nature or by humans, affects the earth’s climate.

13. Nutrient cycles connect past, present, and future forms of life.

14. The hydrologic cycle is a way nature renews water quality.

15. In hundreds of years, we have released large quantities of fossil fuels that took millions of years to form.

1. Destruction of tropical rain forests will help accelerate ____________________.

2. Tropical rain forests may be prevented from returning to cleared areas if an irreversible ______________ is reached.

3. Ecologists assign every type of organism in an ecosystem to a feeding level or ____________________.

4. Organisms that convert simple inorganic compounds into nutrients, without sunlight, are called ____________________ .

5. Organisms that cannot produce their own food and, therefore, must eat other organisms, are called ____________________.

6. Decomposers are mainly bacteria and ____________________.

7. ____________________ refers to how fast producers can make the chemical energy that is stored in their tissues and that is potentially available to other organisms (consumers) in an ecosystem.

8. Despite its low NPP, the ____________________ produces more of the earth’s biomass per year than any other ecosystem or life zone.

9. Temporary oceanic, atmospheric, and terrestrial storage sites for nutrients are called ____________________.

10. The three major processes in the water cycle are ____________________, ____________________, and ____________________.

11. Carbon cycles through the biosphere and depends on the process of ____________________ and ____________________.

12. Nitrogen fixation is accomplished by specialized ____________________ in the soil and ____________________ in aquatic environments.

13. The rotten-egg smell coming from volcanoes and anaerobic decomposition in bogs and swamps comes from the gas ____________________.

14. A group of individuals of the same species living in the same place at the same time is a(n) ____________________.

15. ____________________ can help scientists understand large and very complex systems by allowing them to change variables and project possible changes.

1. In the accompanying figure, notice that the fox (secondary consumer) is in the process of pouncing on the rabbit. If humans were to remove that predator (fox), what would be the effects on the rest of the ecosystem? Be as specific as possible.

2. In the accompanying figure, notice that heat is lost by each component of the ecosystem, and that the sun is shown entering at only one point in the system. Explain how this is representative of the two laws of energy (two laws of thermodynamics).

3. Examine the accompanying figure. Notice the amount of average net primary productivity gets smaller and smaller as you move down the list of terrestrial ecosystems and, similarly, in the list of aquatic ecosystems. What is the common factor in the terrestrial system that causes the decline? What is the common factor in the aquatic system that causes the decline there?

4. Consider the concept of trophic levels, and explain why it may be necessary for humans to eat less meat. How much energy is lost from one level to the next? Use numbers to support your argument.

5. In the plains states of the U.S. (Kansas, Nebraska, Texas, etc.), agricultural withdrawal of groundwater from aquifers has greatly exceeded the supply. Explain why removal of this resource will have long-term effects on the hydrologic cycle.

1. Letter D, at the base of the pyramid given above, represents what group of organisms?

2. How many kilocalories have been lost between level A and level D?

3. Why is heat shown as being lost to the environment?

4. What group is indicated by letter E, to which all organisms in the pyramid eventually succumb?

5. Why would there be fewer organisms at level A than at any level below it?