Deck 28: Bacteria and Archaea

Question 1

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.

Answer 1

B

Question 2

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 2

B

Question 3

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)all of the above

Answer 3

D

Question 4

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 5

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)direct sequencing
C)Enrichment culture and direct sequencing are equally efficient methods.

Question 6

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)enrichment culture
B)direct sequencing
C)Enrichment culture and direct sequencing are equally efficient methods.

Question 7

Starting in 1945,Escherichia coli became a bacterium of choice to study basic cellular processes and gene function.What specific feature of E.coli is responsible for its rise to prominence as a model system?

A)ability to grow in suspension culture and on agar plates
B)ability to transfer a copy of a plasmid from one cell to another
C)very fast growth rate
D)the fact that it has small,circular DNA

Question 8

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)all of the above

Question 9

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
E)all of the above

Question 10

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 11

What organisms are most numerous on Earth?

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

Question 12

Microbiologists use the Gram stain to aid in 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 membrane

Question 13

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)Its cell walls are made primarily of peptidoglycan.
C)The organism does not have nucleus.
D)It can survive at a temperature over 100°C.

Question 14

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)All of the above are correct.

Question 15

You have decided to grow E.coli to isolate a specific enzyme.For your experiment,which of the following conditions would enable you to grow a maximum amount of bacteria in the shortest time possible?

A)growing in suspension culture at 25°C
B)growing on agar plates at 25°C
C)growing in suspension culture at 37°C
D)growing on agar plates at 37°C
E)As long as you grow bacteria at 25°C,it does not matter if they are grown on agar plates or in suspension culture.

Question 16

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 17

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 plasmids.
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 18

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)sugar
E)any of the above

Question 19

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.

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

What is the characteristic feature of the Chlamydiales phylum?

A)unusual flagella
B)formation of colonies
C)rod shape
D)parasitic life cycle
E)all of the above

Question 22

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 23

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 24

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 25

Which of the following can a chemolithotrophic bacteria use as a source of energy?

A)light
B)glucose
C)water
D)ammonia

Question 26

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 27

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 28

You have found a prokaryote that is able to form colonies and produce oxygen.To what lineage does it belong?

A)Cyanobacteria
B)Chlamydiales
C)Actinobacteria
D)Proteobacteria
E)Crenarchaeota

Question 29

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)All of the above answers apply.

Question 30

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

A)Spirochaeles
B)Proteobacteria
C)Cyanobacteria
D)Actinobacteria
E)All of the above can perform photosynthesis.

Question 31

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 32

What do nitrogen fixation genes and antibiotic resistance genes have in common?

A)They are located on the bacteria chromosome.
B)They spread by lateral gene transfer.
C)They exist only in parasitic proteobacteria.
D)They evolved recently.
E)All of the above answers apply.

Question 33

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 34

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 35

Which of the following statements best defines a psychrophile?

A)A micro-organism capable of living in extremely cold environments.
B)A micro-organism capable of living in environments with an extremely high salt concentration.
C)A micro-organism that lives in an environment with moderate temperatures.
D)A micro-organism capable of living in extremely hot environments.

Question 36

Bacteria participate in the nitrogen cycle through which mechanism?

A)nitrogen fixation
B)nitrification
C)denitrification
D)decomposition
E)all of the above

Question 37

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 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