Deck 25: Environmental Microbiology

Question 1

Nitrogenase is:

A)oxygen sensitive
B)only produced by Rhizobium
C)a N₂ fixing enzyme
D)two of these choices

Answer 1

D

Question 2

The sulfur cycle is of special importance to:

A)terrestrial life
B)Pseudomonas
C)proteolytic bacteria
D)aquatic life

Answer 2

D

Question 3

Most denitrification is due to _____.

A)Rhizobium
B)Azotobacter
C)Pseudomonas
D)Nitrosomonas

Answer 3

C

Question 4

Some microbes can survive drought by forming _____.

A)fimbriae
B)spores
C)cysts
D)two of these choices

Question 5

Producers obtain CO₂ from _____.

A)eating other producers
B)the atmosphere
C)dead bodies
D)coal

Question 6

In the phosphorous cycle,inorganic phosphates are converted to _____,a water-soluble nutrient used by both plants and microorganisms.

A)phosphorous
B)hydrophosphates
C)orthophosphate
D)betaphosphate

Question 7

Denitrification is:

A)a process by which nitrates are reduced to nitrous oxide or N₂
B)a process by which nitrites are reduced to ammonia
C)a process by which amino acids are converted to pyruvate
D)largely due to aerobic environments

Question 8

In the sulfur cycle many microbes convert sulfhydryl (-SH)groups to _____,which is toxic to living things.

A)hydrogen sulfate
B)hydrogen sulfide
C)sulfuric acid
D)sulfate

Question 9

Sulfate-reducing bacteria are characteristically _____.

A)strict anaerobes
B)Desulfovibrio
C)utilizing sulfate as a final electron acceptor
D)all of these choices

Question 10

Nitrification is characterized by all of the following except:

A)carried out by autotrophic bacteria
B)supplies plants with a usable nitrogen source
C)produces ammonia
D)nitrogen is oxidized in both of the two steps

Question 11

The mechanism whereby Rhizobium and the legume associate is characterized by all of the following except:

A)multiplies in the vicinity of legume roots
B)bacteria release proteases to digest cell wall
C)change from free-living to swarmer cells
D)swarmers invade root hairs to become bacteroids

Question 12

The most usable form of sulfur by microorganisms and plants is:

A)sulfide
B)sulfate
C)hydrogen sulfide
D)sulfhydryl

Question 13

The loss of water from pores of plant leaves is called:

A)transpiration
B)respiration
C)evaporation
D)two of these choices

Question 14

Which is a primary symbiotic nitrogen fixer?

A)Azotobacter
B)Rhizobium
C)Cyanobacteria
D)Clostridium

Question 15

Nitrogen-fixing bacteria include:

A)cyanobacteria
B)Clostridium
C)Klebsiella
D)all of these choices

Question 16

Which of the following statements about ecology is incorrect?

A)The biosphere consists of three layers- the hydrosphere, lithosphere and atmosphere.
B)Communities with many populations of organisms are more stable than those with fewer populations.
C)Vegetative cells must have water.
D)The sun is the ultimate source of energy for all organisms in any ecosystem.

Question 17

Which would not be the habitat for terrestrial species of some microorganisms?

A)desert
B)tundra
C)tropical rain forest
D)freshwater lake

Question 18

Sulfur oxidation is carried out by _____.

A)Thiobacillus
B)Desulfovibrio
C)Desulfomonas
D)Desulfotomaculum

Question 19

Which of the following microbes is not a producer in the environment?

A)photosynthetic bacteria
B)heterotrophic bacteria
C)cyanobacteria
D)protista
E)two of these choices

Question 20

Nitrogen-fixing bacteria:

A)oxidize ammonia to nitrates or nitrites
B)oxidize ammonia to nitrous oxide
C)reduce nitrates to nitrites
D)reduce nitrogen gas to ammonia

Question 21

Cytophaga,found in soil,is characterized by _____.

A)being a fungus
B)cellulose degradation
C)being strictly aerobic
D)being a protozoan decomposer

Question 22

Which of the following statements about biogeochemical cycles is true?

A)Not all living microbes require carbon.
B)Nitrogen fixing bacteria must be in association with legumes.
C)Thiobacillus oxidizes hydrogen sulfide to sulfuric acid.
D)Cyanobacteria are the primary symbiotic nitrogen fixer.

Question 23

Tertiary treatment of sewage could include:

A)chlorine
B)UV light
C)ozone
D)all of these choices

Question 24

Which is the order of purification procedures for water?

A)flocculation →chlorination →filtration →particulate settling
B)synthetic organic chemicals →particulate settling →filtration
C)chlorination →filtration →particulate settling →nitrification
D)particulate settling →flocculation treatment →filtration →chlorination

Question 25

The primary producers in the ocean are:

A)prions
B)viruses
C)phytoplankton
D)two of these choices

Question 26

What results from the biological oxygen demand (BOD)being high and the water becoming anaerobic?

A)a more efficient decomposition of wastes
B)increased need for sulfur
C)decreased need for carbon
D)death of most members of any ecosystem

Question 27

The most predominant microbial group found in soil is:

A)fungi
B)bacteria
C)protozoa
D)viruses

Question 28

In testing for water purity,the presumptive test would include:

A)Eosin-methylene blue agar
B)lactose broth
C)nutrient agar
D)Gram stain

Question 29

The predominant genus of microbe found in ambient air is _____.

A)Cladosporium
B)Bacillus
C)Staphylococcus
D)Candida

Question 30

Which of the following symptoms is not part of sick building syndrome?

A)headache and burning eyes
B)nosebleeds and skin problems
C)dizziness and nausea
D)feeling like there is too much air

Question 31

The indicator organism for human pathogens in a water supply is:

A)Escherichia coli
B)Salmonella typhi
C)Poliovirus
D)Staphylococcus aureus

Question 32

Which of the following is used to control the number of microbes in the air?

A)UV light
B)triethylene glycol
C)cellulose acetate filters
D)all of these choices

Question 33

Which of the following statements about soil is false?

A)anywhere in the soil you can find snottites
B)viruses can be used for biocontrol of insect pests in soil
C)humus is the nonliving organic matter in soil
D)carbon in the soil is continuously recycled

Question 34

The trickling filtration system employs a bed of rocks that have been coated with:

A)Sphaerotilus
B)Pseudomonas
C)Beggiatoa
D)two of these choices

Question 35

Soil contains human pathogens,for instance _____.

A)Clostridium tetani
B)Bacillus anthracis
C)Clostridium perfringens
D)all of these choices

Question 36

How do the ONPG and MUG test detect microorganisms in water?

A)color is changed by enzymes secreted by coliform bacteria
B)gas production in cultures of lactose broth
C)observing dark colonies of coliform organisms on EMB-lactose agar
D)colonies forming on surface of a sterile absorbent pad

Question 37

Phytoplankton include:

A)cyanobacteria
B)diatoms
C)dinoflagellates
D)all of these choices

Question 38

The most problematic yet common form of tertiary treatment of water is:

A)chlorine
B)UV light
C)ozone
D)X-rays

Question 39

Molds in soil serve to:

A)aid in decomposition
B)aid in nitrogen-fixation
C)form a network with mycelia
D)two of these choices

Question 40

Eutrophication leads to:

A)a decrease in oxygen
B)plants become very dense
C)abundant nutrient enrichment
D)all of these choices

Question 41

During which step is an aeration tank used?

A)A
B)B
C)C
D)D

Question 42

Which of the following statements about extreme environments is incorrect?

A)Hydrothermal vents can reach temperatures up to 350° C.
B)Hydrothermal fluids contain mixed communities of eubacteria and archaea.
C)Bacteria that are involved in anaerobic oxidation of methane are rare in samples.
D)In different zones of a chimney wall there are different communities of microbes.

Question 43

Nitrogen stripping occurs during _____.

A)A
B)B
C)C
D)D

Question 44

What is the meaning of biological oxygen demand (BOD)? Why is it important in pollution? What do microbes have to do with this?

Question 45

What is the greenhouse effect? What effect might global warming have on infectious disease?

Question 46

How does Sphaerotilus interfere with an activated sludge system?

A)by coating rocks with a slimy film and decomposing organic matter
B)by removing flocculating substances
C)by proliferating and allowing floating matter to carry contaminants into sewage effluent
D)by converting nitrates to nitrogen gas and blocking the nitrogen stripping tank

Question 47

Which term has been incorrectly matched?

A)biogeochemical cycles - recycling of life-essential elements and water
B)nitrogenase - functional nitrogen-fixing enzyme
C)swarmer cells - organisms that can invade waterlogged soils
D)nitrate - form of nitrogen most usable in plant metabolism

Question 48

Which term is correctly matched with its definition?

A)biotic factors - interaction of organisms with other organisms
B)ecology - all organisms in a given area with abiotic and biotic factors
C)ecosystem - organisms that are always found in a given environment
D)niche - recycling of life-essential elements and water

Question 49

A niche includes all of the following except:

A)the taxonomy of an organism
B)the role an organism plays in the ecosystem
C)an organisms use of abiotic factors in its environment
D)the interactions an organism has with other organisms

Question 50

Which bacteria are found in the desert and are oil eating?

A)Halobacterium
B)Desulfurovibrio
C)Thiobacillus
D)Arthrobacter

Question 51

Why are soil microorganisms so important to the nitrogen cycle? Describe the 3 roles bacteria play in the nitrogen cycle.

Question 52

What are the consequences of heat acting as a water pollutant?

A)causes silting of waterways
B)reduces light reaching plants in water
C)increases the salinity and acidity of water
D)alters habitats and kinds of organisms present

Question 53

Which statement about septic tanks is correct?

A)Pouring poisons and grease down the drain may kill the tank's beneficial microbes.
B)Sludge moves continually into a drainage leaching field.
C)Drainage fields last for more than 50 years.
D)Two of these choices

Question 54

Which step produces drinkable water?

A)A
B)B
C)C
D)D

Question 55

What role do microbes play in degradation of plastics?

A)Microbes could be used to disintegrate plastics, like soda bottles and disposable diapers.
B)Bacteria could assist in making biodegradable plastics.
C)Bacteria could speed up the incineration process.
D)Two of these choices