Deck 28: Bacteria and Archaea

Question 1

You acquire a soil sample and run an enrichment culture on it.You provide the organisms in the culture with all of the ingredients required for growth except for nitrogen.What result do you expect to have at the end of your experiment?

A)Nitrogen-fixing bacteria will significantly outnumber those incapable of fixing nitrogen.
B)Nitrogen-fixing bacteria will not be present in the culture.
C)Nitrogen-fixing bacteria will be present but not at significantly greater numbers than non-nitrogen-fixing species.
D)Nitrogen-fixing bacteria will be present,but will be significantly outnumbered by non-nitrogen-fixing species.

Answer 1

A

Question 2

Researchers have found a new type of bacteria,and they want to determine its phylum.What would be the most reliable method to do so?

A)Conduct a Gram-stain test.
B)Perform an analysis of metabolic pathways.
C)Determine the ribosomal RNA sequence of the bacteria.
D)Analyze the morphological characteristics of the bacteria.

Answer 2

C

Question 3

An organic solvent widely used in industrial processes 1,1,1-trichloroethane (TCA) is a major environmental pollutant affecting human health and damaging the ozone layer.Recently researchers isolated the first bacteria able to degrade TCA.They found that the bacteria use hydrogen as an electron donor,TCA as electron acceptor,and acetate as a carbon source.Based on the preceding information,deduce the method used to isolate these bacteria.

A)Gram staining
B)enrichment culture
C)direct sequencing
D)seeding

Answer 3

B

Question 4

Microbiologists use the Gram stain to aid in the identification of bacteria.What is the major difference between Gram-positive and Gram-negative bacteria?

A)structure of the lipids in the plasma membrane
B)presence or absence of muramic acid in the cell wall
C)presence or absence of peptidoglycan in the cell wall
D)presence or absence of outer plasma membrane

Question 5

Bacteria and Archaea are most easily distinguished from each other by their _____.

A)chromosome structure
B)habitat
C)transcription and translation mechanism
D)reproduction method

Question 6

Imagine that you are given some chemoorganotrophic bacteria to grow.What should you use as a source of energy for this type of bacteria?

A)light
B)methane
C)ammonia
D)hydrogen sulfide
E)sugar

Question 7

You might be interested to know how many different types of bacteria live on the shower curtain in your bathroom.What is the most efficient method for answering this question?

A)producing a molecular phylogeny
B)enrichment culture
C)direct sequencing
D)Enrichment culture and direct sequencing are equally efficient methods.

Question 8

You need to identify the major type of bacteria living on the shower curtain in your bathroom and find out what they use as a food source.What is the most efficient method for answering this question?

A)enrichment culture
B)producing a molecular phylogeny
C)direct sequencing
D)Enrichment culture and direct sequencing are equally efficient methods.

Question 9

What is the right progression of steps for a direct-sequencing experiment?

A)Lyse cells,purify DNA,amplify genes by PCR,and insert genes into plasmid.
B)Lyse cells,insert genes into plasmid,purify DNA,and amplify genes by PCR.
C)Lyse cells,insert genes into plasmid,amplify genes by PCR,and purify DNA.
D)Purify DNA,amplify genes by PCR,lyse cells,and insert genes into plasmid.

Question 10

Some researchers have begun attempting to clean up oil spills by adding nonindigenous microbial hydrocarbon degraders to the spill,in the hopes that these bacteria will neutralize the dangerous chemicals in the spill.This is an example of _____.

A)bioremediation via fertilization
B)seeding
C)production of a new antibiotic
D)use of extremophiles for cleanup of organic solvents

Question 11

Which are evolutionarily more closely related?

A)Bacteria and Archaea
B)Archaea and Eukarya
C)Bacteria and Eukarya
D)Bacteria,Eukarya,and Archaea are equally related to each other.

Question 12

What do Bacteria have in common with Archaea but not with Eukarya?

A)unicellular structure
B)peptidoglycan cell walls
C)transcription mechanism begins with formylmethionine
D)absence of nucleus
E)DNA associated with histone proteins

Question 13

Use of synthetic fertilizers often leads to the contamination of groundwater with nitrates.Nitrate pollution is also a suspected cause of anoxic "dead zones" in the ocean.Which of the following might help reduce nitrate pollution?

A)growing improved crop plants that have nitrogen-fixing enzymes
B)adding nitrifying bacteria to the soil
C)adding denitrifying bacteria to the soil
D)using ammonia instead of nitrate as a fertilizer

Question 14

What organisms are most numerous on Earth?

A)eukaryotes
B)archaea
C)prokaryotes
D)plants
E)insects

Question 15

Which of the following extremophiles might researchers most likely use as a model for the earliest organisms on Earth?

A)a bacterium capable of living at extremely high salinity
B)a bacterium found on another planet or moon
C)an archaean capable of surviving in the polar ice caps
D)an anaerobic archaean species
E)a bacterium that thrives in a highly acidic environment

Question 16

Which of the following describe all existing bacteria?

A)pathogenic,omnipresent,morphologically diverse
B)extremophiles,tiny,abundant
C)small,harmful,fast-growing
D)tiny,ubiquitous,metabolically diverse
E)morphologically diverse,metabolically diverse,extremophiles

Question 17

Multicellularity and large body size of eukaryotic organisms requires high metabolic rates and efficient ATP production by aerobic respiration.How did bacteria change Earth's atmosphere to enable aerobic respiration?

A)Oxygenic photosynthesis by cyanobacteria significantly increased the amount of oxygen in the atmosphere.
B)Splitting of water during anaerobic respiration by cyanobacteria dramatically increased the amount of oxygen in the atmosphere.
C)Nitrogen fixation by cyanobacteria decreased the amount of nitrogen in the atmosphere,leading to simultaneous increase of oxygen.
D)Anaerobic respiration by cyanobacteria increased the amount of oxygen in the atmosphere by reducing the amount of iron oxides that are able to react instantly with oxygen.

Question 18

While examining a rock surface,you have discovered an interesting new organism.Which of the following criteria will allow you to classify the organism as belonging to Bacteria but not Archaea or Eukarya?

A)It is unicellular.
B)Cell walls are made primarily of peptidoglycan.
C)Organism does not have nucleus.
D)The lipids in its plasma membrane consist of glycerol bonded to straight-chain fatty acids.
E)It can survive at a temperature over 100°C.

Question 19

What is the goal of bioremediation?

A)Improve human health with the help of living organisms such as bacteria.
B)Clean up areas polluted with toxic compounds by using bacteria.
C)Improve soil quality for plant growth by using bacteria.
D)Improve bacteria for production of useful chemicals.
E)Killing pathogenic bacteria with the use of antibiotics.

Question 20

To establish a link between a specific bacterium and a skin disease,researchers have shown that bacterium was present in sick persons but not in healthy individuals.They isolated the bacterium in a pure culture and demonstrated that experimental healthy animals injected with this culture became sick.What other experiment do researchers need to perform to be absolutely sure that the bacterium is responsible for the disease?

A)Demonstrate that the bacterium belongs to the pathogenic lineage.
B)Demonstrate that the bacterium is not able to live outside of humans or animals.
C)Isolate bacterium from an infected sick animal and demonstrate that it is the same bacterium as the one used for infection.
D)Demonstrate all of the above.
E)No experiments need to be done,because there are enough data to establish that skin disease is caused by the investigated bacterium.

Question 21

Which of the following lineages do not contain bacteria that are photosynthetic?

A)Spirochaeles
B)Proteobacteria
C)Cyanobacteria
D)Actinobacteria

Question 22

Figure 28.1

Bacteria able to perform the NH₄⁺ + NO₂⁻ → N₂ + 2H₂O reaction have been discovered in laboratory bioreactors and wastewater treatment systems.Researchers predicted that these bacteria should exist in oceans.They measured the concentration of NH₄⁺,NO₂⁻,NO₃⁻,and O₂ in the Black Sea as a function of water depth (M.Kuypers et al.2003 Anaerobic ammonium oxidation by anammox bacteria in the Black Sea.Nature 422:
608-11)to determine where in the sea the bacteria might live.Analyzing data presented in Figure 28.1 above,at what depth would you expect to find the bacteria? (Note:
In the figure,different scales are used to show concentrations of NH₄⁺,NO₂⁻,NO₃⁻,and O₂. )

A)in the top 5 meters
B)in the top 50 meters
C)at a depth of 75 meters
D)at a depth of 92 meters
E)below 100 meters

Question 23

While examining soil from a cornfield,you found a new type of bacteria that turns purple when treated with Gram stain.What lineage might it belong to?

A)Spirochaeles
B)Proteobacteria
C)Cyanobacteria
D)Firmicutes
E)Chlamydiales

Question 24

A biologist trying to determine the mechanism of ATP production in a newly discovered bacterium provides several different substrates on which the bacteria can feed.Which of the following results would indicate that the species uses fermentation to produce ATP?

A)The bacteria utilize glucose,and produce CO₂ as a by-product of respiration.
B)After the bacteria break down their substrate,the biologist notices a rotten egg smell.
C)The biologist discovers that the bacteria are able to produce organic molecules by metabolizing methane.
D)After exposure to amino acids,the bacteria produce a smell like rotting flesh.

Question 25

During cellular respiration,some bacteria use CH₄ as an electron donor and O₂ as an electron acceptor.What is the name for this group of bacteria?

A)methanogens
B)methanotrophs
C)organotrophs
D)nitrifiers

Question 26

Biologists sometimes divide living organisms into two groups:
Autotrophs and heterotrophs.How do these two groups differ?

A)They use different sources of energy.
B)They use different electron acceptors.
C)They use different sources of carbon.
D)They differ in the way they generate ATP.

Question 27

You have found a new prokaryote.What line of evidence would support your hypothesis that the organism is a cyanobacterium?

A)It is able to form colonies and produce oxygen.
B)It is an endosymbiont.
C)It forms chains called mycelia.
D)You determine that it can cause Lyme disease.
E)It lacks cell walls.

Question 28

A newly discovered organism is found to use sulfide (S²−)for aerobic respiration and use CO₂ from the air as a source of carbon,much like a plant.This organism must be a(n)_____.

A)photoautotroph
B)chemoorganoautotroph
C)photoheterotroph
D)chemolithotrophic heterotroph
E)chemolithoautotroph

Question 29

What experiment can distinguish between high-GC Gram-positive bacteria and low-GC Gram-positive bacteria?

A)analysis of cell shape
B)Gram-staining test
C)DNA analysis
D)analysis of metabolic pathways

Question 30

A bacterium was grown in two test tubes filled with media rich in glucose.One tube was sealed to produce anaerobic conditions,and the other was not.A third uninoculated,unsealed tube was used as a control.Glucose utilization by this bacterium causes acid production,which is indicated by a lightening of the media color.If the bacterium is able to produce ATP only by respiration,which result do you expect to receive?

A)lightening of media in the sealed tube only
B)lightening of media in the unsealed tube only
C)lightening of media in the sealed and unsealed tubes only
D)lightening of media in the control tube only
E)lightening of media in all three tubes

Question 31

What is the major goal of cellular respiration?

A)reduce an electron acceptor molecule
B)supply cell with fixed carbon
C)produce ATP
D)generate O₂
E)utilize glucose

Question 32

The purple non-sulfur bacterium Rhodospirillum grows best as a photoheterotroph.What are the most favorable sources of energy and carbon for this bacterium?

A)methane and CO₂
B)fructose and light
C)light and CO₂
D)glucose

Question 33

What is the characteristic feature of the Chlamydiales phylum?

A)unusual flagella
B)formation of colonies
C)rod shape
D)parasitic life cycle

Question 34

What kind of molecules serve as electron acceptors in cellular respiration?

A)water
B)polar molecules
C)molecules with high potential energy
D)molecules with low potential energy
E)molecules in an excited state

Question 35

Which of the following groups is characterized by unusual flagella contained within a structure called the outer sheath?

A)Spirochaeles
B)Proteobacteria
C)Firmicutes
D)Chlamydiales
E)Euryarchaeota

Question 36

Which of the following is correct?

A)During oxygenic photosynthesis,water is used as a source of electrons;during non-oxygenic photosynthesis,hydrogen sulfide is used as a source of electrons.
B)During oxygenic photosynthesis,hydrogen sulfide is used as a source of electrons;during non-oxygenic photosynthesis,water is used as a source of electrons.
C)During oxygenic photosynthesis,oxygen is used as a source of electrons;during non-oxygenic photosynthesis,water is used as a source of electrons.
D)During oxygenic photosynthesis,oxygen is used as a source of electrons;during non-oxygenic photosynthesis,hydrogen sulfide is used as a source of electrons.

Question 37

You run an osteology lab,where students are able to study the bone structure of various species.To produce clean bones,you introduce insects and bacteria to remove all remaining flesh.Which bacteria would be the best purchase for your lab?

A)Spirochaetes
B)Actinobacteria
C)Chlamydiae
D)Cyanobacteria
E)Proteobacteria

Question 38

When some bacteria use lactose as a source of energy,they produce propionic acid and CO₂.What is the name for this process?

A)fermentation
B)cellular respiration
C)chemical synthesis
D)photosynthesis
E)carbon fixation