Deck 15: Microbial Ecosystems

Question 1

Intestinal E.coli and Methanobrevibacter smithii are members of the same:

A)ecosystem
B)biofilm
C)genus
D)niche
E)guild

Answer 1

A

Question 2

Which two lanes appear to have DNA from the most closely related or identical microbes/populations?

A)Lanes 3 and 4
B)Lanes 4 and 5
C)Lanes 5 and 6
D)Lanes 8 and 9
E)Lanes 12 and 14

Answer 2

C

Question 3

Today,the most effective technique for analyzing microbial community structure is based on this analysis.

A)Sequencing small subunit rRNA.
B)Identification of the catabolic enzymes present.
C)Isolation and characterization of microbes from the community.
D)Enrichment culture technique for microbial isolation.
E)Identification of metabolic intermediates that accumulate in the environment.

Answer 3

A

Question 4

FACS may employ which all the following EXCEPT:

A)laser fluorescence detector
B)fluorescently labeled antibodies
C)gfp promoterless gene constructs
D)laser probe to destroy unlabeled cells
E)differential flow to move cells to a variety of end containers

Question 5

Given the information in this figure and your knowledge from Chapter 10,what aspect of the illustration may not be strictly accurate?

A)RNA sequencing is not possible because hairpin formations inhibit polymerase activity
B)Sequencing runs of 1400 base pairs are unlikely to occur with existing technology
C)Universal primer lengths are too short for conventional PCR
D)No choices are correct
E)Universal primer lengths are too long for conventional PCR

Question 6

Microbes are able to generate energy through the:

A)oxidation of organic compounds only.
B)reduction of organic compounds only.
C)oxidation of inorganic and organic compounds.
D)reduction of inorganic and organic compounds.
E)synthesis of ATP.

Question 7

DNA-SIP technology relies upon the differential:

A)AT richness of organisms growing in an environmental sample
B)Isotope incorporation into DNA of assimilatory microbes within an environmental sample
C)Distribution of nitrogen in the proteins of actively metabolizing cells
D)Distribution of carbon into the cytoplasmic constituents of actively growing cells
E)None is a correct choice

Question 8

Which of these technologies employs heavy isotopes of nitrogen and carbon to enrich for DNA samples from actively growing organisms?

A)RNA-SIP
B)Metagenomic sequencing
C)DDGE
D)FISH
E)SSU rRNA sequencing

Question 9

Microbes which display the same physiological responses to environment and others within a community are said to occupy the same:

A)ecosystem
B)biofilm
C)community
D)niche
E)environment

Question 10

In the microbial world,an "operational taxonomic unit" is defined as any group of microbes that share at least __________ sequence identity of their SSU rRNA gene.

A)100%
B)97%
C)90%
D)80%
E)50%

Question 11

Which of these technologies gives direct sequence information?

A)RNA-SIP
B)Metagenomics
C)DDGE
D)FISH
E)T-RFLP scanning

Question 12

What is the estimated percentage of microbial species on Earth have been grown in culture?

A)1 -5%
B)5 - 10 %
C)10 - 15%
D)15-20%
E)20 - 25%

Question 13

Given your knowledge from previous chapters,particularly chapter 14,which of the genes listed is likely to display the most sequence diversity,and why?

A)SSU .rRNA because its ubiquity means evolutionary diversity is inevitable
B)nif because nitrogen fixation may have evolved independently in a wide variety of organisms
C)pmoA becuae both membrane bound and cytoplasmic forms of the enzyme have been identified
D)all of the choices are valid
E)not all choices are valid,but those with validity still do not provide enough information for an evauation to be made

Question 14

Which of these regulates the formation of biofilms?

A)photosynthesis
B)quorum sensing
C)water availability
D)catabolite repression
E)end product repression

Question 15

How mught quorum sensing knowledge assist in medical antibiotic applications?

A)Quorum sensors are antimicrobial in nature and their overexpression and purification may lead to a novel antibiotic class
B)Quorum sensing inhibition might reduce bacterial communication and toxin release
C)Quorum sensing stimulation might allow bacteria to outgrow nutrient sources
D)Quorum sensing stimulation may allow biofilm reduction
E)All are plausible choices

Question 16

Select the pair of microbes belonging to the same guild:

A)Methanobrevibacter smithii,E.coli
B)E)coli,Caulobacter
C)Pseudomonas,Desulfovibrio
D)Azotobacter,Pseudomonas
E)None is a correct choice

Question 17

Which of these is NOT an advantage of living in a biofilm community?

A)protection from predation
B)water availability
C)protection from toxins
D)nutrient availability
E)all are advantages of biofilm community living

Question 18

What is the best classification of primary producers found in hydrothermal vents on the ocean bottom?

A)photosynthetic
B)organotrophs
C)chemolithoautotrophs
D)chemoorganoheterotrophs
E)photolithoautotrophs

Question 19

FISH is a fluorescent microscopic technique used to differentiate microbes using this fluorescently labeled material.

A)antibody
B)antigen
C)protein
D)DNA probe
E)lipid

Question 20

Which of these is the LEAST important physiological activity to consider when studying an ecosystem?

A)primary production by chemolithotrophs
B)primary production by phototrophs
C)decomposition by chemoorganotrophs
D)methane production by methanogens
E)biogeochemical cycling of the elements

Question 21

Which of these represents MOST of the ocean's organisms?

A)fish
B)sea mammals
C)archaea
D)marine viruses
E)bacteria

Question 22

What is the % salinity of the ocean?

A)1% or less
B)3)5%
C)8%
D)15%
E)35%

Question 23

Soil texture classification is based on the percent of __________ that make up the soil.

A)air,water,and solids
B)water and solids
C)sand,silt,and clay
D)sand and water
E)clay and sand

Question 24

The coastal marine waters contain on average about _________ microbial cells per ml.

A)10
B)100
C)10,000
D)1 million
E)100 million

Question 25

Where is the soil's rhizosphere?

A)Areas in contact with bodies of water.
B)Areas in direct contact with the atmosphere.
C)Areas surrounding plant roots.
D)Patches that support nitrogen fixation.
E)Zones that contain animal life.

Question 26

Lignocellulose is primarily mineralized by this group of organisms during plant decomposition.

A)fungi
B)Gram positive bacteria
C)Gram negative bacteria
D)Archaea
E)slime molds

Question 27

Which of these best summarizes the contribution of cyanobacteria in the open ocean?

A)primary carbon production
B)oxygenation of the waters
C)nitrogen fixation
D)primary carbon production and oxygenation of the waters
E)primary carbon production,oxygenation of the waters,and nitrogen fixation

Question 28

Which of these characterizes dead zones in the ocean?

A)Low temperatures.
B)Lacking microbial life.
C)Being hypoxic.
D)Being oligotrophic.
E)Lacking nutrients.

Question 29

Proteorhodopsin has been found in many marine bacteria,including the SAR-11 group.This protein has activity :

A)In the detection of light.
B)As a light-driven proton pump.
C)As a photosynthetic reaction center.
D)As a repressor for global regulation.
E)As an activator for global regulation.

Question 30

Which of these represents MOST of the ocean's biomass?

A)fish
B)sea mammals
C)fish and sea mammals
D)marine plants
E)microbes

Question 31

Approximately what percent of primary production reaches the ocean floor?

A)one
B)five
C)ten
D)twenty
E)forty

Question 32

The fluorescence seen in this photograph is a result of:

A)gfp promoterless gene constructs
B)fluorescently labeled antibodies
C)fluorescence of ethidium bromide,a DNA detecting stain
D)fluorescently-labeled primers used for DNA synthesis
E)fluorescently-labeled primers used for RNA synthesis

Question 33

What is the average temperature of the world's ocean waters?

A)2 to 3°C
B)8 to 10°C
C)12 to 15°C
D)18 to 20°C
E)22 to 25°C

Question 34

Which elements necessary for microbial life are often limiting in the ocean?

A)magnesium and calcium
B)nitrogen and phosphorous
C)magnesium and chloride
D)sodium and calcium
E)potassium and magnesium

Question 35

To grow the widest diversity of marine microbes from the open ocean requires growth media that contain which of the following?

A)High concentrations of vitamins.
B)High concentrations of carbohydrates and salts.
C)High concentrations of siderophores.
D)Very low carbon concentrations.
E)Very low concentrations of proteins and high concentrations of carbohydrates.

Question 36

How would you best classify most of the microbes from marine environments that cannot be isolated?

A)obligate anaerobes
B)obligate oligotrophs
C)obligate halophiles
D)extreme halophiles
E)extreme thermophiles

Question 37

Most of the organic matter in soil comes from the decomposition of:

A)animals
B)plants
C)fungi
D)protozoa
E)algae

Question 38

Which of these pairs best categorizes water below the thermocline in a lake during the summer?

A)warm and aerobic
B)low density and anaerobic
C)cold and aerobic
D)low density and aerobic
E)cold and anaerobic

Question 39

Soil microbes surrounding the plant root contribute to plant growth by providing the plants with all of the following EXCEPT:

A)a source of fixed nitrogen.
B)soluble phosphorus.
C)water.
D)a usable carbon source.
E)protection from pathogens.

Question 40

In terrestrial environments,where is the greatest microbial diversity found?

A)lakes
B)rivers and streams
C)soil
D)rocks
E)springs

Question 41

What possible sources of energy may be used by microbes that live deep within the Earth?

A)carbon dioxide and oxygen
B)hydrogen gas and ferrous iron
C)nitrate and sulfate
D)sulfate and ferric iron
E)nitrate and ferric iron

Question 42

What is the deepest that viable microorganisms have been found in the Earth's crust?

A)100 meters
B)500 meters
C)1000 meters
D)1500 meters
E)3000 meters

Question 43

Given the information in this figure and your knowledge from Chapter 10,what limitations to this technique exist or may exist?

A)RNA sequencing is not possible because hairpin formations inhibit polymerase activity
B)Sequencing runs of 1400 base pairs are unlikely to occur with existing technology
C)Universal primers for SSU rRNA have not yet been designed
D)No choices are correct
E)Universal primers for SSU rRNA cannot be designed as there are no highly enough conserved sequence regions

Question 44

Which gel constituents are essential in ensuring partial DNA strand separation in the DGGE technique? (Select all that apply)

A)Urea gradient
B)Temperature gradient
C)GC-rich primer clamp
D)Polyacrylamide
E)Applied voltage

Question 45

A soil with 50% clay,20% silt and 10% sand is classified texturally as:

A)loam
B)sandy loam
C)clay
D)silty clay loam
E)sandy clay loam

Question 46

Which gel constituents are essential in facilitating DNA strand separation in the DGGE technique? (Select all that apply)

A)Urea gradient
B)Temperature gradient
C)GC-rich primer clamp
D)Polyacrylamide
E)Applied voltage

Question 47

What are humic substances?

A)clay particles
B)recalcitrant organic molecules
C)glucose molecules
D)carbonates and phosphates
E)silt and sand

Question 48

Moderate temperature and neutral pH geothermal springs in terrestrial environments may contain __________ as primary producers.

A)chemolithotrophs
B)oxygenic phototrophs
C)anoxygenic phototrophs
D)oxygenic and anoxygenic phototrophs
E)oxygenic and anoxygenic phototrophs and chemolithotrophs

Question 49

Which of these processes likely contributes LEAST to growth of microbes in subsurface environments

A)Chemolithoautotrophy
B)Organic detritus deposition from surface layers
C)Chemolithoheterotrophy
D)Chemoorganoheterotrophy
E)All contribute equally

Question 50

Which of these technologies could be used to determine the related ness of organisms? (Select all that apply)

A)RNA-SIP
B)Metagenomic sequencing
C)DDGE
D)FISH
E)SSU rRNA sequencing

Question 51

A sandy loam soil will possess:

A)50% clay,20% sand,10% silt
B)15% clay,60% sand,85% silt
C)50% clay,20% sand,80% silt
D)80% clay,20% sand,15% silt
E)40% clay,20% sand,10% silt

Question 52

A soil with 35% clay,65% silt and 20% sand is classified texturally as:

A)loam
B)sandy loam
C)clay
D)silty clay loam
E)sandy clay loam

Question 53

From the study of deep subsurface microbiology,what is the approximate upper temperature limit for microbial growth?

A)80°C
B)90°C
C)100°C
D)110°C
E)120°C

Question 54

Silt is defined as: (Select all that apply)

A)organic matter found in soil
B)mineral particulate with an intermediate size
C)a textural component of soil
D)a product of hemicellulose digestion
E)material found where lower pH soils abound

Question 55

A silt loam soil will possess:

A)50% clay,20% sand,10% silt
B)10% clay,10% sand,80% silt
C)50% clay,20% sand,80% silt
D)80% clay,20% sand,15% silt
E)40% clay,20% sand,10% silt

Question 56

Due to the environment from which it can be isolated,we can characterize Beggiatoa as: (Select all that apply)

A)Barophilic
B)Chemolithotrophic
C)Photolithotrophic
D)Psychrophilic
E)oligotrophic

Question 57

Which organisms has NOT been discovered as part of a hydrothermal vent comminity?

A)Tube worms
B)Shrimp
C)Anemones
D)Octopus
E)Kelp

Question 58

Which of the following may NOT have been produced by microbial activity?

A)Arsenate
B)Gold ore
C)Uranium ore
D)Sulfate
E)Hydrogen sulfide

Question 59

All of the following but one are xenobiotics that frequently contaminate our terrestrial environments.Which one does NOT represent a xenobiotic?

A)polychlorinated biphenyls
B)polycyclic aromatics
C)lignin
D)trichloroethylene
E)nitroaromatics

Question 60

What possible sources of energy may be used by microbes living in hydrothermal vents?

A)nitrate and methane
B)methane and sulfide
C)sulfide and nitrate
D)sulfate and nitrate
E)sulfate and methane

Question 61

Deep subsurface environment are considered to be void of microbial life.

Question 62

The use of living organisms to clean up chemically contaminated soils is called __________.

Question 63

Sulfur emitted from hydrothermal vents is in the form of __________.

Question 64

Microbes can form a biofilm on any type of surface.

Question 65

Due to the environment from which it can be isolated,we can characterize Thiobacillus as: (Select all that apply)

A)Barophilic
B)Chemolithotrophic
C)Photolithotrophic
D)Thermophilic
E)oligotrophic

Question 66

Estimates of overall microbial abundance in the ocean indicate that more Archaea are present than Bacteria.

Question 67

The part of the soil that immediately surrounds the plant root is called the __________.