Deck 27: Environmental Microbiology

Question 1

For the biogeochemical cycles of the following elements,which does NOT have an atmospheric cycle?

A)carbon
B)phosphorus
C)sulfur
D)nitrogen

Answer 1

B

Question 2

Which of the following is required for composting?

A)addition of non-biodegradable materials
B)addition of nitrogen and phosphorus sources
C)periodic turning or raking of the compost pile
D)addition of thermophilic microbes
E)constant anaerobic conditions

Answer 2

C

Question 3

Biochemical oxygen demand is a measure of the

A)number of bacteria present in a water sample.
B)amount of oxygen present in a water sample.
C)amount of organic matter present in a water sample.
D)amount of undissolved solid matter present in a water sample.
E)amount of nitrogen in a water sample.

Answer 3

C

Question 4

All of the following are habitats for extremophiles EXCEPT

A)an acid mine wash.
B)the topmost portions of the Atlantic Ocean.
C)inside rock.
D)a salt-evaporating pond.
E)100°C water.

Question 5

Bioremediation of petroleum

A)takes place under aerobic conditions.
B)takes place under anaerobic conditions.
C)The amount of oxygen does not make any difference.

Question 6

Which of the following requires aerobic conditions?

A)nitrogen fixation
B)sludge digestion
C)primary sewage treatment
D)secondary sewage treatment
E)water treatment

Question 7

Fill in the blanks with the most appropriate set of terms.In a(n)________ sludge digester,________ bacteria decrease organic solids by degrading them.

A)activated;benthic
B)sedimentation;suspended
C)tertiary;Zooglea
D)anaerobic;methane-producing
E)aerobic;hydrogen-gas producing.

Question 8

All of the following organisms are involved in carbon fixation EXCEPT

A)green and purple sulfur bacteria.
B)cyanobacteria.
C)lichens.
D)algae.
E)mycorrhizae.

Question 9

In freshwater lakes and ponds,the majority of photosynthetic microbes are located in the ________ zone(s).

A)benthic
B)profundal
C)limnetic
D)littoral
E)benthic and profundal

Question 10

Which of the following organisms is using sulfur as a source of energy?

A)Thiobacillus: H₂S → S⁰
B)Desulfovibrio: SO₄²⁻ → H₂S
C)Proteus: Amino acids → H₂S
D)Redwood tree: SO₄²⁻ → Amino acids
E)Photosynthetic bacteria: H₂S → S⁰

Question 11

Which of the following is NOT a symbiotic pair of organisms?

A)elk and rumen bacteria
B)orchid and mycorrhizae
C)termites and cellulose-degrading bacteria
D)bean plant and Rhizobium
E)sulfur and Thiobacillus

Question 12

All of the following are used in secondary sewage treatment EXCEPT

A)trickling filters.
B)sludge granules or floc formation.
C)aeration.
D)anaerobic digestion.
E)activated sludge.

Question 13

The guano deposited by seabirds is used a source for which of the following fertilizer components?

A)phosphate
B)nitrate
C)sulfate
D)carbonate
E)potassium

Question 14

6H₂S + 6CO₂ 6S⁰ + glucose

A)takes place under aerobic conditions.
B)takes place under anaerobic conditions.
C)The amount of oxygen does not make any difference.

Question 15

NH₃ → NO₂⁻

A)takes place under aerobic conditions.
B)takes place under anaerobic conditions.
C)The amount of oxygen does not make any difference.

Question 16

All of the following are true of mycorrhizae EXCEPT

A)they are fungi that form beneficial relationships with plants.
B)an example is the food delicacy truffles.
C)the arbuscular mycorrhizae are a type of ectomycorrhizae.
D)they enable plants to absorb soil nutrients.
E)ectomycorrhizae extend the surface area of roots for nutrient absorption.

Question 17

Adding untreated sewage to a freshwater lake would cause the biochemical oxygen demand to

A)increase.
B)decrease.
C)stay the same.
D)The answer cannot be determined based on the information provided.

Question 18

Figure 27.1

Which term in Figure 27.1 describes step V?

A)ammonification
B)denitrification
C)dissimilation
D)nitrification
E)nitrogen fixation

Question 19

Figure 27.1

Which step in Figure 27.1 represents anaerobic respiration?

A)I
B)II
C)III
D)IV
E)V

Question 20

Figure 27.1

Which step in Figure 27.1 represents the following reaction: amino acid (-NH₂)→ NH₃?

A)I
B)II
C)III
D)IV
E)V

Question 21

Drinking water supplies are routinely tested for the presence of

A)Giardia.
B)Cryptosporidium.
C)fecal coliforms.
D)fecal viruses.
E)Vibrio.

Question 22

Which wastewater treatment process produces BOD-containing effluent used for irrigation?

A)anaerobic sludge digestion
B)primary sewage treatment
C)secondary sewage treatment
D)tertiary sewage treatment
E)water treatment

Question 23

Besides the use of chlorine,other method(s)used to disinfect municipal water include

A)ozone.
B)nitrite.
C)flocculant.
D)UV light.
E)both UV light and ozone.

Question 24

Figure 27.1

Which of the following terms describes step III in Figure 27.1?

A)ammonification
B)denitrification
C)nitrification
D)nitrogen fixation
E)assimilation

Question 25

Which wastewater treatment process is responsible for removal of most of the BOD in sewage?

A)anaerobic sludge digestion
B)primary sewage treatment
C)secondary sewage treatment
D)tertiary sewage treatment
E)water treatment

Question 26

Figure 27.1

Nitrification is beneficial to farmers.It is represented by which step in Figure 27.1?

A)I
B)II
C)III
D)IV
E)V

Question 27

Bacteria can increase the Earth's temperature by

A)generating a great deal of heat in metabolism.
B)producing CH₄,which is a greenhouse gas.
C)using the greenhouse gas CO₂.
D)providing nutrients for plant growth.
E)oxidizing CH₄.

Question 28

Filtration to remove protozoa occurs in

A)anaerobic sludge digestion.
B)primary sewage treatment.
C)secondary sewage treatment.
D)tertiary sewage treatment.
E)water treatment.

Question 29

Which of the following is an assimilation process?

A)Thiobacillus: H₂S → S⁰
B)Desulfovibrio: SO₄²⁻ → H₂S
C)Proteus: Sulfhydryl-containing amino acids → H₂S
D)Redwood tree: SO₄²⁻ → Sulfhydryl groups of amino acids
E)Photosynthetic bacteria: H₂S → S⁰

Question 30

In the ONPG and MUG test for fecal coliforms,a sample that is positive for E.coli will be

A)positive for ONPG;fluorescent in UV light.
B)negative for ONPG;fluorescent in UV light.
C)positive for ONPG;non-fluorescent in UV light.
D)negative for ONPG;non-fluorescent in UV light.

Question 31

Which of the following terms describes NO₃⁻ → NO₂⁻ → N₂O → N₂?

A)ammonification
B)denitrification
C)nitrification
D)nitrogen fixation
E)anaerobic respiration

Question 32

Figure 27.2

Where are photosynthetic bacteria most likely to be found in Figure 27.2?

A)a
B)b
C)c
D)a and b
E)b and c

Question 33

Aerobic respiration occurs in

A)anaerobic sludge digestion.
B)primary sewage treatment.
C)secondary sewage treatment.
D)tertiary sewage treatment.
E)water treatment.

Question 34

Which of the following is NOT characteristic of fecal coliforms?

A)gram-negative
B)non-spore forming
C)rod-shaped
D)lactose-fermenting
E)pathogenic

Question 35

Which one of the following processes in sewage treatment requires bacterial metabolism?

A)chlorination
B)primary treatment
C)removal of BOD
D)sedimentation
E)None of the answers is correct.

Question 36

Which of the following do NOT fix atmospheric nitrogen?

A)cyanobacteria
B)lichens
C)mycorrhizae
D)Rhizobium
E)Azotobacter

Question 37

Which of the following is mismatched?

A)CO₂ + 4H₂ → CH₄ + 2H₂O - Methane-producing bacteria
B)2 NO₂⁻ + O₂→ 2 NO₃ - Nitrobacter
C)6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ - Clostridium
D)N₂ + 6H⁺ → 2NH₃ - Beijerinckia
E)SO₄²⁻ + 10H⁺ → H₂S + 4H₂O - Desulfovibrio

Question 38

Sedimentation of sludge occurs in

A)anaerobic sludge digestion.
B)primary sewage treatment.
C)secondary sewage treatment.
D)tertiary sewage treatment.
E)water treatment.

Question 39

Zoogloea form flocculent masses in

A)anaerobic sludge digestion.
B)primary sewage treatment.
C)activated sludge digestion.
D)tertiary sewage treatment.
E)water treatment.

Question 40

The product of which process contains the highest BOD?

A)anaerobic sludge digestion
B)primary sewage treatment
C)secondary sewage treatment
D)tertiary sewage treatment
E)water treatment

Question 41

The release of phosphate-containing detergents into a river would

A)kill algae.
B)increase algal growth.
C)kill bacteria.
D)improve the water quality.
E)None of the answers is correct.

Question 42

Nitrogen fixation by bacteria occurs only in the root nodules of leguminous plants.

Question 43

Coliforms detected in water samples always have a fecal source.

Question 44

Bioaugmentation involves

A)adding nitrogen and phosphorus to an area in need of remediation.
B)adding specialized microbes to an area in need of remediation.
C)producing humus from plant waste.
D)producing a methane by-product for powering facility equipment.
E)using microbes to filter out impurities from leach water.

Question 45

The dense growth of algae in an algal bloom leads to increased oxygen levels in lakes that enhance the habitat for fish.

Question 46

Bioremediation involves the use of microbes to degrade or detoxify pollutants.

Question 47

The BOD is a measurement of the amount of bacteria present before and after the sewage treatment process.

Question 48

Untreated sewage is released into a river.Which of the following statements is FALSE?

A)The untreated sewage is a health hazard.
B)The untreated sewage increases the BOD.
C)The untreated sewage decreases the dissolved oxygen.
D)The untreated sewage kills bacteria.
E)All of the statements are true.

Question 49

If nitrates are important in the nitrogen cycle,why are they also contaminants of the water systems?

A)If ingested,nitrate is converted to nitrogen gas,which is toxic at low levels.
B)When ingested,nitrate is converted to nitrite and competes for oxygen in the blood,which is especially harmful to infants.
C)It indicates the presence of fecal contamination.
D)It is the major cause of eutrophication.
E)None of these pertain to nitrate.

Question 50

Put the stages of anaerobic sludge digestion in order I.anaerobic fermentation produces carbon dioxide and organic acids
II)methane produced from product of previous stage
III)hydrogen and carbon dioxide produced from product of previous stage

A)I,II,III
B)II,I,III
C)I,III,II
D)II,III,I
E)III,II,I

Question 51

The water from tertiary sewage treatment can be used as drinking water.

Question 52

Figure 27.2

Where are the benthic microbes such as Desulfovibrio and Clostridium most likely to be found in Figure 27.2?

A)a
B)b
C)c
D)a and b
E)b and c

Question 53

What is true about the nitrogen cycle?

A)The form of nitrogen present in significant levels in the atmosphere is easily assimilated by most organisms.
B)Most of the nitrogen in the atmosphere exists as organic molecules.
C)The activity of specific types of microorganisms is important to convert atmospheric nitrogen molecules into usable forms.
D)Both most of the nitrogen in the atmosphere exists as organic molecules and the activity of specific types of microorganisms is important to convert atmospheric nitrogen molecules into usable forms.
E)All organisms can incorporate atmospheric nitrogen into their proteins and nucleic acids.

Question 54

Microorganisms in deep-sea vents and caves serve as autotrophic primary producers in the absence of sunlight.

Question 55

What is true about the seawater microbiota?

A)Large Archaea populations exist under the seafloor.
B)In seawater ecosystems nitrogen is not fixed but obtained from run-off from land sources.
C)Ocean life depends on the marine phytoplankton.
D)Estimate places 1/3 of all life on the planet within the seafloor.
E)Large Archaea populations exist under the seafloor and the marine phytoplankton supports all ocean life.

Question 56

What is true about the sulfur cycle?

A)H₂S is the oxidized form of sulfur.
B)Green and purple photosynthesizing bacteria oxidize H₂S.
C)Sulfates are utilized to become part of the carbohydrate molecules.
D)H₂S represents a source of energy for some autotrophic bacteria.
E)Both green and purple photosynthesizing bacteria oxidize H₂S and H₂S represents a source of energy for some autotrophic bacteria.

Question 57

The bacteriological safety of drinking water is determined by testing water samples for the presence of human pathogens.

Question 58

In water treatment,the purpose of flocculation is to remove microbes,such as Giardia and Cryptosporidium.

Question 59

In small communities lacking municipal sewage systems,sewage is treated in septic systems or oxidation ponds.

Question 60

One problem related to numerous septic systems in sandy soil is that

A)the high porosity can lead to contamination of water supplies with leached chemicals or pathogens.
B)the systems may become impaired because the effluent will not drain properly.
C)few microbes exist in sandy soil to completely degrade the leached organic matter.
D)grains of sand clog the systems.
E)some human pathogens tend to multiply within a sand matrix increasing the likelihood of disease transmission.

Question 61

A newspaper headline reported "Algal Bloom Kills Fish." What actually caused fish death,given that the algae were not toxic? What could have caused the algal bloom?

Question 62

An oil spill occurred in the waters near a local beach and the oil is depositing on the shore.Describe the methods that might be used to clean up the spill that involve the activity of microorganisms.Include a discussion of the limitations for each method.

Question 63

What is the effect of discharging primary-treated sewage on the BOD and dissolved O₂ (DO)of the receiving body of water? What is the effect of secondary-treated sewage on the BOD and DO?

Question 64

Differentiate endomycorrhizae from ectomycorrhizae and give an example of each.

Question 65

Based on your knowledge of extremophiles and endoliths,describe the characteristics you would expect of microorganisms capable of living on Mars or other non-Earth environments.