Deck 27: Environmental Microbiology

Question 1

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

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

Answer 1

B

Question 2

Which of the following requires aerobic conditions?

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

Answer 2

C

Question 3

Which of the following is required for composting?

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

Answer 3

A

Question 4

Figure 27.1

Which step in Figure 27.1 represents anaerobic respiration?

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

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

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 7

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

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

Question 8

What stage of sewage treatment produces methane?

A) tertiary treatment
B) primary treatment
C) secondary treatment
D) sludge digestion
E) None of the stages of sewage treatment produce methane.

Question 9

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

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

Question 10

All of the following are habitats for extremophiles EXCEPT

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

Question 11

6H₂S + 6Co₂ light 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 12

All of the following are used in secondary sewage treatment EXCEPT

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

Question 13

Figure 27.1

Which term in Figure 27.1 describes step V?

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

Question 14

Biochemical oxygen demand is a measure of the

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

Question 15

All of the following are true of mycorrhizae EXCEPT

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

Question 16

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

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

Question 17

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

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

Question 18

NH3 → No₂-

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

Question 19

All of the following organisms are involved in carbon fixation EXCEPT

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

Question 20

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

A) onions and arbuscules
B) elk and rumen bacteria
C) bean plant and Rhizobium
D) orchid and mycorrhizae
E) sulfur and Thiobacillus

Question 21

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

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

Question 22

Drinking water supplies are routinely tested for the presence of

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

Question 23

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 24

Residual chlorine must be maintained in

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

Question 25

Bacteria can increase the Earthʹs temperature by

A) using the greenhouse gas Co₂.
B) providing nutrients for plant growth.
C) oxidizing CH4.
D) producing CH4, which is a greenhouse gas.
E) generating a great deal of heat in metabolism.

Question 26

Which of the following is mismatched?

A) N2 + 6H+ → 2NH3  Beijerinckia
B) Co₂ + 4H₂ → CH4 + 2H₂O  Methane-producing bacteria
C) SO42- + 10H+ → H₂S + 4H₂O  Desulfovibrio
D) 6Co₂ + 6H₂O → C6H12O6 + 6o₂  Clostridium
E) 2 No₂- + o₂→ 2 NO3  Nitrobacter

Question 27

Which of the following do NOT fix atmospheric nitrogen?

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

Question 28

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 29

Which of the following terms describes NO3- → No₂- → N2O → N2?

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

Question 30

Filtration to remove protozoa occurs in

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

Question 31

Zoogloea form flocculent masses in

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

Question 32

Aerobic respiration occurs in

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

Question 33

Which of the following is an assimilation process?

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

Question 34

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

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

Question 35

Which of the following is NOT characteristic of fecal coliforms?

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

Question 36

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 37

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 38

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

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

Question 39

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 40

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 41

The purpose of tertiary sewage treatment is to remove all of the phosphorus, nitrogen, and BOD left from secondary treatment.

Question 42

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) b and c
E) a and b

Question 43

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

Question 44

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 45

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.

Question 46

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

Question 47

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

Question 48

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

Question 49

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

Question 50

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

Question 51

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

Question 52

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

Question 53

The release of phosphate-containing detergents into a river would

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

Question 54

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

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

Question 55

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

Question 56

Bacteria that are used as biosensors

A) degrade hazardous chemicals.
B) have chlorophyll.
C) do not emit light in the presence of a hazardous chemical.
D) may use the lux operon.
E) migrate to the hazardous chemical.

Question 57

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

Question 58

In the early 1900s, cities such as Philadelphia reduced the incidence of typhoid fever by

A) using tertiary water treatment systems.
B) filtering municipal drinking water through sand-bed filters.
C) isolating human carriers.
D) requiring residents to boil drinking water.
E) mass vaccination of residents.