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1 | |
An aquatic ecosystem is most often defined in limnology as a(n): |
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| | A) | suitable habitat. |
| | B) | habitat that supports one or more populations. |
| | C) | set of top carnivores. |
| | D) | chemical cycle or energy structure. |
| | E) | group of interacting species. |
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2 | |
Secondary productivity, measured as total fish production per hectare, is most strongly related to lake: |
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| | A) | annual primary productivity. |
| | B) | community of fish species. |
| | C) | community of littoral macrophytes. |
| | D) | origin (glacial vs. other). |
| | E) | size, defined by the surface area. |
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3 | |
The microbial loop is most likely to affect fish production in which one of the following ways? Production is: |
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| | A) | decreased by the microbial loop because of decreased ecological efficiency in the trophic structure. |
| | B) | increased because young-of-the-year fish depend on small zooplankton for food. |
| | C) | increased when the microbial loop is dominant, because microbes have a more favorable surface-to-volume ratio. |
| | D) | not related to the microbial loop. |
| | E) | reduced because the fish are infected with Saprolegnia. |
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4 | |
"Optimal," in the context of fish physiology and the scope for growth argument, refers to: |
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| | A) | minimal environmental conditions for the population. |
| | B) | extreme environmental conditions that produce death in some individuals. |
| | C) | initial conditions. |
| | D) | safest (least-extreme) conditions. |
| | E) | the temperature at which enzyme reaction rate is at its maximum rate. |
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5 | |
Which is most likely true for a juvenile fish? |
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| | A) | Assimilated energy is allocated only to growth. |
| | B) | Assimilation rate is zero until the juvenile begins to develop into an adult. |
| | C) | Energy allocated toward reproduction is zero until the juvenile begins to develop into an adult. |
| | D) | Energy allocation is not possible until the juvenile matures, because the budget cannot be balanced. |
| | E) | Respiration for the total fish is higher than it will be for the adult stage. |
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6 | |
Which is most true about the measurement of photosynthesis? |
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| | A) | 13C isotopes are used to make bicarbonate, for estimating primary productivity. |
| | B) | Dark bottles measure gross primary productivity directly. |
| | C) | Light bottles measure net primary productivity directly. |
| | D) | Net is always greater than gross primary productivity, because there is always some respiration. |
| | E) | Only plants photosynthesize and only animals respire. |
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7 | |
Tropical Lakes are expected to have low annual rates of primary productivity because: |
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| | A) | carbon dioxide is a limiting factor at higher average temperatures. |
| | B) | diel net primary productivity is low because of the unfavorable ratio of carbon fixation to respiration, relative to conditions in temperate lakes. |
| | C) | net primary productivity decreases as temperature increases. |
| | D) | relatively long nights inhibit respiration. |
| | E) | the higher the average temperature, the lower the respiration rate. |
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8 | |
Phosphorus is often a factor that limits algal growth. In oligotrophic lakes, the epilimnion is dominated by small algal cells (in the 1μm range) because: |
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| | A) | carbon, not phosphorus is limiting for larger cells when nutrients are scarce. |
| | B) | nitrogen fixation restores nitrate in oligotrophic lakes. |
| | C) | of the favorable surface-to-volume ratio enjoyed by small cells. |
| | D) | scope for growth is smaller when nutrients are scarce. |
| | E) | small cells are less sensitive to cold temperatures associated with oligotrophic conditions. |
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9 | |
Photosynthesis in productive lakes (during the daylight hours, when light is above the compensation point): |
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| | A) | adds CO2 to lake water. |
| | B) | adds H+ to lake water. |
| | C) | adds water to the total volume of the lake. |
| | D) | decreases ANC. |
| | E) | increases pH of lake water. |
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10 | |
An individual fish can feed and respire over a range of temperature. The difference between feeding and respiration rates is called the: |
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| | A) | ecological efficiency. |
| | B) | metabolic potential. |
| | C) | scope for growth. |
| | D) | secondary productivity. |
| | E) | temperature-compensated metabolic rate. |
2005 McGraw-Hill Higher Education