Biogeochemical
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____
1. The flow of nutrients from the non-living to the living and back to the non-living components of an ecosystem is referred
to as a(n) ________ cycle.
a. trophic
b. biogeochemical
____
____
____
c. energy
d. filtering
2. You would expect decomposition and mineralization to occur most rapidly under
a. cool but moist conditions
c. anaerobic conditions such as occur in a
swamp or bog
b. warm, moist, aerobic condditions at a near d. acidic, moist, aerobic conditions
neutral pH
3. Decomposition by bacteria and fungi relies on the activity of __________________.
a. extracellular slime
c. extracellular enzymes
b. spore formation
d. polysaccharrides
4. In lakes and ponds, decomposition occurs primarily in the ___________ zone
a. limnic
c. littoral
b. little decomposition ever occurs in
d. benthic
lakes and ponds which is the reason
they eventually fill in.
____
____
____
____
5. The source of all carbon in living organisms is
a. simple sugars
c. soil organic matter.
b. CO2 in the atmosphere and in water.
d. sedimentary rocks
6. The rate of carbon cycling is determined by the rate of
a. mineral weathering
c. decomposition
b. primary production.
d. both b and c
7. Which of the following nutrients is most closely linked to the energy cycle in ecosystems
a. nitrogen
c. carbon
b. oxygen
d. sulfur
8. Which of these is true concerning the nitrogen cycling in ecosystems?
1. Nitrogen enters ecosystems through two pathways: atmospheric deposition and nitrogen fixation.
2. Ammonium is a form of nitrogen that can be directly used by plants.
3. The atmosphere is the largest pool of nitrogen.
a. 1 only
b. 2 only
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9. In the soil microbial loop
a. soil invertebrates attack plant roots making
them more available to fungal decomposition
b. nutrients released from decaying organic
matter in the soil become tied in a cycle of
microorganisms making them unavailable
to plants in turn leading to desertification
c. 3 only
d. all three are true
c. fungi attacking plant roots increase
mineralization thus fueling further polant
growth further supporting development of
those pathogenic fungi
d. exudated from plant roots fuel microbial
growth in the root zone thereby increasing
decomposition making nutrients tied in
organic matter available to plants
____ 10. Which of the following breaks down most slowly during decomposition of pant material?
a. cellulose
c. protein
b. lignin
d. chitin
____ 11. In ________ biogeochemical cycles, the main reservoirs of nutrients are the atmosphere and the oceans.
a. sedimentary
c. oceanic
b. gaseous
d. marine
____ 12. Which of the following represents a loss of nutrients from an ecosystem?
a. the production of CO2 during respiration
c. the transport of organic matter by a river from
one ecosystem to another
b. the addition of fertilizer to a crop field which
d. actually they all do
is eventually shipped to another location
____ 13. In ________ biogeochemical cycles, the main reservoirs of nutrients are the atmosphere and the oceans.
a. sedimentary
c. oceanic
gaseous
b.
d. marine
____ 14. In ________ biogeochemical cycles, the main reservoirs of nutrients are the soil, rocks, and minerals.
a. sedimentary
c. terrestrial
gaseous
b.
d. rudimentary
____ 15. Which of the following is associated with a loss of nutrients from an ecosystem?
1. the addition of fertilizer to a crop field
2. the production of CO2 during respiration
3. the transport of organic matter by a river from one ecosystem to another
4. the harvesting of a crop by humans
a. 1 only
b. 3 and 4
c. 1, 3 and 4
d. 2, 3 and 4
____ 16. Carbon is released into the atmosphere as CO2 as the result of the process of
a. photosynthesis.
c. respiration.
primary
production.
b.
d. fixation.
____ 17. The rate of carbon cycling is determined by the rate of
decomposition of organic matter
2. weathering
3. photosynthesis
1.
a. 1 only
b. 1 and 3
c. 1, 2 and 3
d. none of these
____ 18. The biogeochemical cycles of one ecosystem are typically independent from those of other ecosystems.
a. True
b. False
____ 19. In any given place, the amount of carbon dioxide in the air is constant from day to day.
a. True
b. False
____ 20. Of the carbon actively involved in the global cycle, most is in the oceans.
a. True
b. False
____ 21. Most carbon is buried in sedimentary rocks
a. True
b. False
____ 22. Precipitation can be a significant input of nutrients in ecosystems.
a. True
b. False
____ 23. The various biogeochemical cycles are largely independent of one another.
a. True
b. False
____ 24. Which of the following holds the least amount of nitrogen?
a. the atmosphere
c. biomass
b. sedimentary rock
d. soils
____ 25. Which of the following forms of nitrogen can be taken up by plants?
a. nitrate
c. NH3
b. NO2
d. organically-bound nitrogen
____ 26. Which of the following provides an input of nitrogen into ecosystems?
1. atmospheric deposition
2. lightning
3. biological fixation by cyanobacteria
4. denitrification by soil bacteria
a. 1, 2 and 3
b. 1 and 3
c. 1 and 2
d. all of these
____ 27. In ________, the process of nutrient cycling is sometimes described as nutrient spiraling.
a. streams and rivers
c. lakes
b. forests
d. oceans
____ 28. Which of the following statements is true?
1.The rate of nutrient cycling in an ecosystem depends only on the rate of photosynthesis.
2.The rate of nutrient cycling in an ecosystem depends only on the rate of decomposition.
3.The rate of nutrient cycling in an ecosystem does not depend on the rate of photosynthesis or the rate of
decomposition.
4. The rate of nutrient cycling in an ecosystem depends on both the rate of photosynthesis and the rate of decomposition.
a. 1 and 2
b. 3 only
c. 1 and 4
d. 4 only
____ 29. The process of conversion of nutrients from an organic form into an inorganic form that plants can use is called
a. immobilization.
c. transpiration.
b. respiration.
d. mineralization.
____ 30. Bacteria are the dominant decomposers of dead animal matter, whereas fungi are the dominant decomposers of dead
plant matter.
a. True
____ 31. Litterbags can be used to study the process of
a. photosynthesis.
b. recycling
b. False
c. nitrificatiopn
d. decomposition