BIOL 2051 LUZAN FINAL - ENTIRE
TEST BANK EXAM QUESTIONS WITH
COMPLETE SOLUTIONS
Which of the following processes does denitrification contribute to?
A) Acid rain
B) Ozone depletion
C) Global warming
D) Acid rain, ozone depletion, and global warming - Answer-D
The two major forms of carbon that remain following microbial degradation are
A) methane, organic matter, and fossil fuels.
B) methane and carbon dioxide.
C) lignin and fossil fuels.
D) organic matter and hydrocarbons. - Answer-B
In the oceans, sulfur exists primarily as
A) hydrogen sulfide (H2S).
B) elemental sulfur (S0).
C) sulfate (SO4
2-
).
D) gypsum (CaSO4). - Answer-C
Sulfide is toxic to respiring organisms because it can combine with metals present in
that serve a critical function in respiration.
A) glycolysis enzymes
B) oxidases
C) NADH
D) cytochromes - Answer-D
40) Lysis of marine algae and cyanobacteria releases a major osmoregulatory
solute,
dimethylsulfoniopropionate (DMSP), which is degraded into the most abundant
organic S
compound in nature,
A) dimethyl sulfide (CH3-S-CH3).
B) hydrogen sulfide (H2S).
C) gypsum (CaSO4).
D) elemental sulfur (S0). - Answer-A
Phosphonate comprises 25% of the phosphorous pool in nature.
A) inorganic
B) organic
C) insoluble
D) biologically unavailable - Answer-B
,Coccolithophores and foraminiferans both use to form their exoskeletons.
A) Si4+
B) Fe3+
C) Ca2+
D) HPO4
2- - Answer-C
Increasing atmospheric carbon dioxide is
A) increasing sedimentation of C, Ca, and Si.
B) increasing the effect of the biological pump.
C) fueling increased primary production in ocean waters.
D) acidifying the ocean and decreasing the rate of formation of calcareous shells. -
Answer-D
44) Studying the redox cycling of Fe in the environment has led to the discovery
A) of bacteria that transfer electrons as a form of electricity.
B) of bacteria that destroy toxic metal ions.
C) of archaea that have Fe in their cell walls.
D) that Fe limits primary production in terrestrial ecosystems. - Answer-A
Nitrogen fixation results in the
A) loss of biologically available N from an ecosystem.
B) formation of nitrogen gas.
C) direct formation of nitrate.
D) addition of biologically available N to an ecosystem. - Answer-D
Nitrous oxide (N2O) is a
A) direct product of ammonification.
B) direct product of nitrogen fixation.
C) potent greenhouse gas that is a product of nitrification.
D) potent greenhouse gas that is a product of denitrification. - Answer-D
Nitrification and anammox both
A) create nitrogen gas, but nitrification is aerobic while anammox is anaerobic.
B) oxidize ammonia, but nitrification uses O2 as an electron acceptor and anammox
uses NO2
-
.
C) are aerobic processes, but nitrification produces NO3
- and anammox produces N2 gas.
D) occur in soils at neutral pH. - Answer-B
The oxidation of occurs both biotically and abiotically, but biotic oxidation is
more common at pH values.
A) Si / low
B) ammonia / high
C) Fe2+ / low
D) Hg0 / low - Answer-C
Human activities have disrupted the carbon cycle by
,A) burning carbon stored as fossil fuels or biomass, thus increasing the amount of
carbon dioxide
in the atmosphere.
B) decreasing the primary productivity of the oceans, resulting in increased
atmospheric carbon
dioxide.
C) burning methane hydrates to produce electricity.
D) acidifying the ocean, resulting in the release of large amounts of dissolved carbon
dioxide
into the atmosphere. - Answer-A
In the natural carbon cycle, carbon dioxide is returned to the atmosphere by the
respiration of
animals and chemoorganotrophic microorganisms. - Answer-true
More carbon is present in dead organic material on Earth than in living organisms. -
Answer-true
Humic substances are difficult to degrade, and therefore they can remain in a system
for
several decades. - Answer-true
Climate scientists are developing methane hydrates to decrease the effects of global
warming. - Answer-false
In a global sense, all nutrient cycles are coupled together. - Answer-true
6) Methanogens, among other compounds, directly use alcohols and fatty acids to
synthesize
methane gas in anoxic environments. - Answer-false
Syntrophic organisms cannot grow fermentatively without a hydrogen-consuming
partner
organism. - Answer-true
Acetogens can ferment glucose into acetate, but methanogens cannot. - Answer-true
When carbon is limiting, sulfate reducers often predominate the system if there are
sufficient
sulfate ions. - Answer-false
The disposal of garbage or sewage in the ocean is known to cause the sudden
growth of
sulfate reducers. - Answer-true
Most chemolithotrophic bacteria that oxidize sulfur are aerobes. - Answer-true
The precipitation of soluble iron ions (Fe2+ and Fe3+) into solid iron occurs
spontaneously
in the presence of organic carbon compounds. - Answer-false
, Abiotic oxidation of Fe2+ requires oxygen and occurs rapidly when the pH is near 7.
- Answer-true
Geobacter uses extracellular electron shuttles to reduce Fe3+ to Fe2+. - Answer-
false
Most metal-oxidizing bacteria produce extracellular structures to deposit insoluble
metal
oxides. - Answer-true
Most environmental phosphorus, such as that found in inorganic phosphate (HPO4
2−), exist
in the +5 oxidation state in nature. - Answer-true
17) Silicoflagellates use silicon compounds in substrate-level phosphorylation. -
Answer-false
Carbon dioxide is the only greenhouse gas produced by anthropogenic activities. -
Answer-false
Ocean acidification decreases the precipitation of calcium carbonate and thus will
probably
affect the cycling of Ca and other nutrients in the ocean. - Answer-true
Mercury has both organic and inorganic forms that are neurotoxic. - Answer-true
The mercury in fish is normally in the form of elemental mercury (Hg0). - Answer-
false
Some bacteria have genes that confer resistance to mercury. - Answer-true
Mercury can serve as a transcriptional activator in the regulation of certain bacterial
genes. - Answer-true
Microbial activity generates methylmercury, which is much less toxic than the
mercuric ion. - Answer-false
Mercury-resistant bacteria detoxify mercury by producing Hg0. - Answer-true
Calcium is cycled most rapidly in terrestrial environments. - Answer-false
Denitrification of fertilizer can result in harmful algal blooms. - Answer-false
The two main processes in the Ca and Si cycles are the biosynthesis of shells and
exoskeletalmaterial as well as the mineralization of these materials in sediments. -
Answer-true
1) What statement is TRUE about stomach microbiota?
A) Few microbes can survive because it is so acidic.
TEST BANK EXAM QUESTIONS WITH
COMPLETE SOLUTIONS
Which of the following processes does denitrification contribute to?
A) Acid rain
B) Ozone depletion
C) Global warming
D) Acid rain, ozone depletion, and global warming - Answer-D
The two major forms of carbon that remain following microbial degradation are
A) methane, organic matter, and fossil fuels.
B) methane and carbon dioxide.
C) lignin and fossil fuels.
D) organic matter and hydrocarbons. - Answer-B
In the oceans, sulfur exists primarily as
A) hydrogen sulfide (H2S).
B) elemental sulfur (S0).
C) sulfate (SO4
2-
).
D) gypsum (CaSO4). - Answer-C
Sulfide is toxic to respiring organisms because it can combine with metals present in
that serve a critical function in respiration.
A) glycolysis enzymes
B) oxidases
C) NADH
D) cytochromes - Answer-D
40) Lysis of marine algae and cyanobacteria releases a major osmoregulatory
solute,
dimethylsulfoniopropionate (DMSP), which is degraded into the most abundant
organic S
compound in nature,
A) dimethyl sulfide (CH3-S-CH3).
B) hydrogen sulfide (H2S).
C) gypsum (CaSO4).
D) elemental sulfur (S0). - Answer-A
Phosphonate comprises 25% of the phosphorous pool in nature.
A) inorganic
B) organic
C) insoluble
D) biologically unavailable - Answer-B
,Coccolithophores and foraminiferans both use to form their exoskeletons.
A) Si4+
B) Fe3+
C) Ca2+
D) HPO4
2- - Answer-C
Increasing atmospheric carbon dioxide is
A) increasing sedimentation of C, Ca, and Si.
B) increasing the effect of the biological pump.
C) fueling increased primary production in ocean waters.
D) acidifying the ocean and decreasing the rate of formation of calcareous shells. -
Answer-D
44) Studying the redox cycling of Fe in the environment has led to the discovery
A) of bacteria that transfer electrons as a form of electricity.
B) of bacteria that destroy toxic metal ions.
C) of archaea that have Fe in their cell walls.
D) that Fe limits primary production in terrestrial ecosystems. - Answer-A
Nitrogen fixation results in the
A) loss of biologically available N from an ecosystem.
B) formation of nitrogen gas.
C) direct formation of nitrate.
D) addition of biologically available N to an ecosystem. - Answer-D
Nitrous oxide (N2O) is a
A) direct product of ammonification.
B) direct product of nitrogen fixation.
C) potent greenhouse gas that is a product of nitrification.
D) potent greenhouse gas that is a product of denitrification. - Answer-D
Nitrification and anammox both
A) create nitrogen gas, but nitrification is aerobic while anammox is anaerobic.
B) oxidize ammonia, but nitrification uses O2 as an electron acceptor and anammox
uses NO2
-
.
C) are aerobic processes, but nitrification produces NO3
- and anammox produces N2 gas.
D) occur in soils at neutral pH. - Answer-B
The oxidation of occurs both biotically and abiotically, but biotic oxidation is
more common at pH values.
A) Si / low
B) ammonia / high
C) Fe2+ / low
D) Hg0 / low - Answer-C
Human activities have disrupted the carbon cycle by
,A) burning carbon stored as fossil fuels or biomass, thus increasing the amount of
carbon dioxide
in the atmosphere.
B) decreasing the primary productivity of the oceans, resulting in increased
atmospheric carbon
dioxide.
C) burning methane hydrates to produce electricity.
D) acidifying the ocean, resulting in the release of large amounts of dissolved carbon
dioxide
into the atmosphere. - Answer-A
In the natural carbon cycle, carbon dioxide is returned to the atmosphere by the
respiration of
animals and chemoorganotrophic microorganisms. - Answer-true
More carbon is present in dead organic material on Earth than in living organisms. -
Answer-true
Humic substances are difficult to degrade, and therefore they can remain in a system
for
several decades. - Answer-true
Climate scientists are developing methane hydrates to decrease the effects of global
warming. - Answer-false
In a global sense, all nutrient cycles are coupled together. - Answer-true
6) Methanogens, among other compounds, directly use alcohols and fatty acids to
synthesize
methane gas in anoxic environments. - Answer-false
Syntrophic organisms cannot grow fermentatively without a hydrogen-consuming
partner
organism. - Answer-true
Acetogens can ferment glucose into acetate, but methanogens cannot. - Answer-true
When carbon is limiting, sulfate reducers often predominate the system if there are
sufficient
sulfate ions. - Answer-false
The disposal of garbage or sewage in the ocean is known to cause the sudden
growth of
sulfate reducers. - Answer-true
Most chemolithotrophic bacteria that oxidize sulfur are aerobes. - Answer-true
The precipitation of soluble iron ions (Fe2+ and Fe3+) into solid iron occurs
spontaneously
in the presence of organic carbon compounds. - Answer-false
, Abiotic oxidation of Fe2+ requires oxygen and occurs rapidly when the pH is near 7.
- Answer-true
Geobacter uses extracellular electron shuttles to reduce Fe3+ to Fe2+. - Answer-
false
Most metal-oxidizing bacteria produce extracellular structures to deposit insoluble
metal
oxides. - Answer-true
Most environmental phosphorus, such as that found in inorganic phosphate (HPO4
2−), exist
in the +5 oxidation state in nature. - Answer-true
17) Silicoflagellates use silicon compounds in substrate-level phosphorylation. -
Answer-false
Carbon dioxide is the only greenhouse gas produced by anthropogenic activities. -
Answer-false
Ocean acidification decreases the precipitation of calcium carbonate and thus will
probably
affect the cycling of Ca and other nutrients in the ocean. - Answer-true
Mercury has both organic and inorganic forms that are neurotoxic. - Answer-true
The mercury in fish is normally in the form of elemental mercury (Hg0). - Answer-
false
Some bacteria have genes that confer resistance to mercury. - Answer-true
Mercury can serve as a transcriptional activator in the regulation of certain bacterial
genes. - Answer-true
Microbial activity generates methylmercury, which is much less toxic than the
mercuric ion. - Answer-false
Mercury-resistant bacteria detoxify mercury by producing Hg0. - Answer-true
Calcium is cycled most rapidly in terrestrial environments. - Answer-false
Denitrification of fertilizer can result in harmful algal blooms. - Answer-false
The two main processes in the Ca and Si cycles are the biosynthesis of shells and
exoskeletalmaterial as well as the mineralization of these materials in sediments. -
Answer-true
1) What statement is TRUE about stomach microbiota?
A) Few microbes can survive because it is so acidic.
