front 1 Which of the following is an ecosystem?
| back 1 all of the organisms living in your aquarium and the abiotic factors with which they interact |
front 2 The biggest difference between the flow of energy and the flow of chemical nutrients in an ecosystem is that _____.
| back 2 nutrients are recycled, but energy is not |
front 3 In an ecosystem, all incoming energy will eventually be _____.
| back 3 dissipated into space as heat |
front 4 Based on the law of conservation of energy, ecosystem ecologists can make which of the following assertions?
| back 4 The total amount of energy stored in organic molecules plus the amounts reflected and dissipated as heat must equal the total solar energy intercepted by the Earth. |
front 5 Which of the following is a primary producer?
| back 5 detritivores |
front 6 Photosynthetic organisms are called _____.
| back 6 autotrophs |
front 7 When you eat an apple, you are a _____.
| back 7 primary consumer |
front 8 The main decomposers in an ecosystem are _____.
| back 8 fungi and prokaryotes |
front 9 Most of the sunlight that reaches Earth _____.
| back 9 is not captured for use by living things |
front 10 The rate at which producers convert solar energy to the chemical energy of organic compounds, minus the energy used during respiration, is called _____.
| back 10 net primary production |
front 11 In a particular ecosystem, what value do you have if you subtract the total respiration of all organisms in that system from the amount of light energy converted to chemical energy by photosynthesizers in the ecosystem?
| back 11 net ecosystem production |
front 12 A study of metabolic rates in a terrestrial community showed that the energy released by respiration exceeded the energy captured in photosynthesis. Which of the following situations is most likely?
| back 12 Community biomass is decreasing. |
front 13 What are the major factors that control primary production in terrestrial ecosystems?
| back 13 temperature and moisture |
front 14 How do iron levels affect phytoplankton populations in a marine ecosystem?
| back 14 Iron stimulates the growth of cyanobacteria, which convert atmospheric N2 to nitrogenous minerals, stimulating the growth of phytoplankton. |
front 15 Eutrophication in lakes is frequently the direct result of _____.
| back 15 nutrient enrichment such as nitrate and phosphate runoffs from land |
front 16 The amount of chemical energy in a consumer's food that is converted to its own new biomass over a period of time is called _____.
| back 16 secondary production |
front 17 In the transition from each trophic level of the food chain to the next trophic level, there is about a _____.
| back 17 90% loss of energy |
front 18 Which of the following best describes the base of a pyramid of net production?
| back 18 It contains the energy captured by photosynthesis. |
front 19 In general, the biomass in an ecosystem will be greatest at the trophic level comprising _____.
| back 19 producers |
front 20 In ecosystems, organisms at the highest trophic levels usually contain less collective biomass than the organisms at lower trophic levels because _____.
| back 20 organisms are inefficient at converting the energy they consume into biomass |
front 21 What is the main abiotic reservoir for elements involved in local biogeochemical cycles, such as calcium and phosphorus?
| back 21 soil |
front 22 Which of the following statements is correct?
| back 22 Over oceans, evaporation exceeds precipitation. |
front 23 The global hydrologic cycle supports a net flow of atmospheric water vapor _____.
| back 23 from the oceans to land |
front 24 Local conditions such as heavy rainfall or the removal of plants may limit the amount of nitrogen, phosphorus, or calcium available to a particular ecosystem, but the amount of carbon available to the system is seldom a problem. Why?
| back 24 Many nutrients come from the soil, but carbon comes from the air. |
front 25 Which of the following is a key part of the carbon cycle?
| back 25 All of the listed responses are correct. |
front 26 By which process is carbon dioxide released from plants back to the atmosphere?
| back 26 respiration |
front 27 Bacteria are especially important in making _____ available to plants.
| back 27 nitrogen |
front 28 The direct product of nitrogen fixation is _____.
| back 28 NH3 |
front 29 Which of the following is true of the nitrogen cycle?
| back 29 Nitrite is converted to nitrate (NO3-) by nitrifying bacteria. |
front 30 The phosphorus cycle lacks a(n) _____ component.
| back 30 atmospheric |
front 31 When researchers at Hubbard Brook Experimental Forest cut down trees and measured subsequent mineral levels in the soil, they found that _____.
| back 31 the amount of nutrients leaving an intact forest ecosystem is controlled by the plants |
front 32 _____ is the science of facilitating the return of a degraded ecosystem to a more natural condition.
| back 32 Restoration ecology |
front 33 The use of organisms to add essential materials to degraded systems defines _____.
| back 33 biological augmentation |