Deck 26: Bacteria and Archaea

Question 1

What is the goal of bioremediation?

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

Answer 1

D

Question 2

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.

Answer 2

enrichment culture

Question 3

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

Answer 3

C

Question 4

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

Question 5

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

Question 6

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) Nitrogen fixation by cyanobacteria decreased the amount of nitrogen in the atmosphere, leading to simultaneous increase of oxygen.
B) Splitting of water during anaerobic respiration by cyanobacteria dramatically increased the amount of oxygen in the atmosphere.
C) Oxygenic photosynthesis by cyanobacteria significantly increased the amount of oxygen in the atmosphere.
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 7

What organisms are most numerous on Earth?

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

Question 8

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

Question 9

Which are evolutionarily more closely related?

A) bacteria and archaea
B) bacteria and eukarya
C) archaea and eukarya
D) Bacteria, eukarya, and archaea are equally related to each other.

Question 10

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) Isolate bacterium from an infected sick animal and demonstrate that it is the same bacterium as the one used for infection.
B) Demonstrate that the bacterium belongs to the pathogenic lineage.
C) Demonstrate that the bacterium is not able to live outside of humans or animals.
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 11

A water sample from a hot thermal vent contained a single- celled organism that had a cell wall but lacked a nucleus. What is its most likely classification?

A) Fungi
B) Animalia
C) Eukarya
D) Archaea
E) Protista

Question 12

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

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

Question 13

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

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

Question 14

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

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

Question 15

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

A) unicellular structure
B) peptidoglycan cell walls
C) absence of nucleus
D) transcription mechanism begins with formylmethionine
E) all of the above

Question 16

Which of the following describe all existing bacteria?

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

Question 17

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) Analyze the morphological characteristics of the bacteria.
C) Perform an analysis of metabolic pathways.
D) Determine the ribosomal RNA sequence of the bacteria.

Question 18

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

Question 19

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) sugar
C) ammonia
D) methane
E) any of the above

Question 20

What are the chemicals secreted by soil fungi that inhibit the growth of bacteria known as?

A) antibiotics
B) hallucinogens
C) antibodies
D) aflatoxins
E) antigens

Question 21

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

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

Question 22

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

Question 23

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

Question 24

A newly discovered organism is found to use hydrogen sulfide H₂S) for aerobic respiration and carbon dioxide CO₂) from the air as a source of carbon, much like a plant. This organism must be a

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

Question 25

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

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

Question 26

What is the characteristic feature of the Chlamydiales phylum?

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

Question 27

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

Question 28

What is the major goal of cellular respiration?

A) produce ATP
B) reduce an electron acceptor molecule
C) supply cell with fixed carbon
D) generate O₂
E) All of the above answers apply.

Question 29

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

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

Question 30

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) nitrifiers
B) organotrophs
C) methanogens
D) methanotrophs

Question 31

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 colour. If the bacterium is able to produce ATP only by respiration, which result do you expect to receive?

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

Question 32

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

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

Question 33

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) Euryarchaeota
E) Chlamydiales

Question 34

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

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

Question 35

Bacteria participate in the nitrogen cycle through which mechanism?

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

Question 36

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

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

Question 37

Figure 26.1
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 26.1 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 metres
B) below 100 metres
C) in the top 50 metres
D) at a depth of 92 metres
E) at a depth of 75 metres

Question 38

A biologist trying to determine the mechanism of adenosine triphosphate 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 carbon dioxide as a by- product of respiration.
B) The biologist discovers that the bacteria are able to produce organic molecules by metabolizing methane.
C) After exposure to amino acids, the bacteria produce a smell like rotting flesh.
D) After the bacteria break down their substrate, the biologist notices a rotten egg smell.
E) The bacteria can only produce ATP in the presence of light.