Question 1

Why did the first bacteria to evolve use anoxygenic metabolism?

Accepted Answer

A)  Because molecular oxygen was not present at high enough levels for oxygenic metabolism until after the action of oxygen-producing photosynthetic bacteria increased atmospheric levels 
B)  Because the Earth's surface was too warm for oxidative phosphorylation to occur 
C)  Because C-fixation was not oxygen dependant 
D)  Because the TCA cycle had not yet evolved 
E)  Because the electron transport chain is oxygen sensitive and compartmentalisation had not yet developed to efficiently partition oxygen within the cell 
A)  Because molecular oxygen was not present at high enough levels for oxygenic metabolism until after the action of oxygen-producing photosynthetic bacteria increased atmospheric levels 
B)  Because the Earth's surface was too warm for oxidative phosphorylation to occur 
C)  Because C-fixation was not oxygen dependant 
D)  Because the TCA cycle had not yet evolved 
E)  Because the electron transport chain is oxygen sensitive and compartmentalisation had not yet developed to efficiently partition oxygen within the cell A

Question 2

The conversion of CH2O + HCO3$\rightarrow$CO2 + CH4 would occur during

Accepted Answer

A)  aerobic respiration. 
B)  anaerobic respiration. 
C)  photorespiration. 
D)  chemorespiration. 
E)  photosynthesis. 
A)  aerobic respiration. 
B)  anaerobic respiration. 
C)  photorespiration. 
D)  chemorespiration. 
E)  photosynthesis. B

Question 3

Which of the following statements about bacteria is CORRECT?

Accepted Answer

A)  The majority of microorganisms in the gut of humans are eukaryotes. 
B)  Bacteria make up about a third of human faecal material. 
C)  Most people have a low population of skin bacteria. 
D)  Current identification of pathogenic bacteria is by PCR (polymerase chain reaction.). 
E)  The majority of bacteria are pathogenic. 
A)  The majority of microorganisms in the gut of humans are eukaryotes. 
B)  Bacteria make up about a third of human faecal material. 
C)  Most people have a low population of skin bacteria. 
D)  Current identification of pathogenic bacteria is by PCR (polymerase chain reaction.). 
E)  The majority of bacteria are pathogenic. B

Question 4

A bacterium picks up and incorporates some free DNA from its environment, which is then integrated into the bacterial cell. This process is called

Accepted Answer

A)  transformation. 
B)  transcription. 
C)  transduction. 
D)  conjugation. 
E)  transfection. 
A)  transformation. 
B)  transcription. 
C)  transduction. 
D)  conjugation. 
E)  transfection.

Question 5

A phylogenetic tree of the evolutionary relationships of the different taxa of microorganisms can best be inferred by

Accepted Answer

A)  fossil remains of bacterial capsules. 
B)  comparison of DNA segments. 
C)  vast numbers of bacteria trapped in sediments. 
D)  comparison of pathogenic bacteria found in animal fossils. 
E)  a comparison of RNA in chloroplasts. 
A)  fossil remains of bacterial capsules. 
B)  comparison of DNA segments. 
C)  vast numbers of bacteria trapped in sediments. 
D)  comparison of pathogenic bacteria found in animal fossils. 
E)  a comparison of RNA in chloroplasts.

Question 6

Cellular structures to surround the cytoplasm evolved early in the evolutionary history of organisms. These structures were initially beneficial because they

Accepted Answer

A)  allowed anaerobic respiration. 
B)  allowed bacteria to thrive under hot conditions. 
C)  concentrated biochemicals in one place. 
D)  gave protection against UV radiation. 
E)  allowed specific chemicals to be retained within the membrane. 
A)  allowed anaerobic respiration. 
B)  allowed bacteria to thrive under hot conditions. 
C)  concentrated biochemicals in one place. 
D)  gave protection against UV radiation. 
E)  allowed specific chemicals to be retained within the membrane.

Question 7

Normal bacterial flora is beneficial to humans and animals because

Accepted Answer

A)  they limit nutrients available to incoming pathogens. 
B)  they limit space available to incoming pathogens. 
C)  they can produce antibiotics and viruses that inhibit incoming pathogens. 
D)  may assist in the breakdown of foods. 
E)  All of the answers are correct. 
A)  they limit nutrients available to incoming pathogens. 
B)  they limit space available to incoming pathogens. 
C)  they can produce antibiotics and viruses that inhibit incoming pathogens. 
D)  may assist in the breakdown of foods. 
E)  All of the answers are correct.

Question 8

To generate energy and make sugars, methanogenic bacteria utilise

Accepted Answer

A)  methane and carbon dioxide. 
B)  hydrogen and carbon dioxide. 
C)  hydrogen and methane. 
D)  methane and oxygen. 
E)  hydrogen and oxygen. 
A)  methane and carbon dioxide. 
B)  hydrogen and carbon dioxide. 
C)  hydrogen and methane. 
D)  methane and oxygen. 
E)  hydrogen and oxygen.

Question 9

A bacterial species is discovered in an aquatic, chemically stratified habitat that possesses intracellular Fe minerals. What might be an unusual feature of these bacteria?

Accepted Answer

A)  The ability to detect north or south 
B)  Using iron or iron compounds as an electron donor 
C)  Tolerance to high alkalinity 
D)  Production of iron oxides, resulting from reacting iron with oxygen 
E)  Transmission of electro-magnetic waves 
A)  The ability to detect north or south 
B)  Using iron or iron compounds as an electron donor 
C)  Tolerance to high alkalinity 
D)  Production of iron oxides, resulting from reacting iron with oxygen 
E)  Transmission of electro-magnetic waves

Question 10

The domain Archaea is most closely related to which super kingdom?

Accepted Answer

A)  Bacteria 
B)  Eubacteria 
C)  Eukarya 
D)  Archaeobacteria 
E)  Chordata 
A)  Bacteria 
B)  Eubacteria 
C)  Eukarya 
D)  Archaeobacteria 
E)  Chordata

Question 11

A particularly gullible consumer decides to waste his money and buy one of the ubiquitous hand cleaning products that claims to kill 99.9% of germs. Soon after using the product, the poorly informed consumer found that his hands were again teeming with bacteria. This could be because

Accepted Answer

A)  bacteria spontaneously generated on his hands. 
B)  the product does not kill bacteria. 
C)  the bacteria have developed resistance to the product. 
D)  some bacteria have an impermeable intracellular layer that prevents the entry of all substances. 
E)  some bacteria produce endospores that are resistant to soaps and disinfectants. 
A)  bacteria spontaneously generated on his hands. 
B)  the product does not kill bacteria. 
C)  the bacteria have developed resistance to the product. 
D)  some bacteria have an impermeable intracellular layer that prevents the entry of all substances. 
E)  some bacteria produce endospores that are resistant to soaps and disinfectants.

Question 12

Compared to the modern age, conditions in the sea 3.5 billion years ago would have been

Accepted Answer

A)  cooler and more salty. 
B)  cooler and less salty. 
C)  warmer and more salty. 
D)  warmer and less salty. 
E)  similar to now. 
A)  cooler and more salty. 
B)  cooler and less salty. 
C)  warmer and more salty. 
D)  warmer and less salty. 
E)  similar to now.

Question 13

The major difference between prokaryotes and eukaryotes is that prokaryotes

Accepted Answer

A)  are able to obtain energy by photosynthesis. 
B)  have a cell wall. 
C)  lack a nucleus. 
D)  are unicellular. 
E)  All of the answers are correct. 
A)  are able to obtain energy by photosynthesis. 
B)  have a cell wall. 
C)  lack a nucleus. 
D)  are unicellular. 
E)  All of the answers are correct.

Question 14

Early bacteria probably obtained their energy by

Accepted Answer

A)  oxidative phosphorylation. 
B)  aerobic respiration. 
C)  anoxygenic photosynthesis. 
D)  utilising UV radiation. 
E)  breakdown of sulphate. 
A)  oxidative phosphorylation. 
B)  aerobic respiration. 
C)  anoxygenic photosynthesis. 
D)  utilising UV radiation. 
E)  breakdown of sulphate.

Question 15

A common reference system for classifying bacteria used by taxonomists is

Accepted Answer

A)  the Linnaean system. 
B)  the DNA sequences. 
C)  gram staining. 
D)  the Bergey system. 
E)  Phenotypic characteristics. 
A)  the Linnaean system. 
B)  the DNA sequences. 
C)  gram staining. 
D)  the Bergey system. 
E)  Phenotypic characteristics.

Question 16

Cyanobacteria are an important subgroup of Bacteria. Which of the statements about cyanobacteria is INCORRECT?

Accepted Answer

A)  The ability of some cyanobacteria to fix nitrogen is used in rice cultivation. 
B)  Cyanobacteria may grow extensively in water and produce peptide toxins which are harmful to animals. 
C)  Early photosynthetic cyanobacteria are thought to be responsible for the earth's atmosphere becoming oxygen rich. 
D)  Stromatolites, which are formed by cyanobacteria are the oldest fossil evidence of life on earth. 
E)  Cyanobacteria contain chlorophyll and like other photosynthetic organisms, generate molecular oxygen during photosynthesis. 
A)  The ability of some cyanobacteria to fix nitrogen is used in rice cultivation. 
B)  Cyanobacteria may grow extensively in water and produce peptide toxins which are harmful to animals. 
C)  Early photosynthetic cyanobacteria are thought to be responsible for the earth's atmosphere becoming oxygen rich. 
D)  Stromatolites, which are formed by cyanobacteria are the oldest fossil evidence of life on earth. 
E)  Cyanobacteria contain chlorophyll and like other photosynthetic organisms, generate molecular oxygen during photosynthesis.

Question 17

Prokaryotes can be divided into two major lineages: Archaea and Bacteria. Archaea differ from Bacteria in that Archaea

Accepted Answer

A)  have membrane-bound organelles. 
B)  do not have a cell wall. 
C)  have distinctive lipids in the cell membrane. 
D)  have a cytoskeleton. 
E)  have a larger ribosome similar to eukaryotes. 
A)  have membrane-bound organelles. 
B)  do not have a cell wall. 
C)  have distinctive lipids in the cell membrane. 
D)  have a cytoskeleton. 
E)  have a larger ribosome similar to eukaryotes.

Question 18

A microbiologist is asked to identify a species of bacteria which is approximately 300nm in diameter. What means would the microbiologist need to use to accurately visualise the bacteria in some detail?

Accepted Answer

A)  Light microscopy 
B)  Ultraviolet reflectance microscopy 
C)  Matrix assisted laser desorption/ionisation-time of flight mass spectrometry 
D)  Cyanin and/or methylene blue endocytotic staining 
E)  Scanning electron microscopy 
A)  Light microscopy 
B)  Ultraviolet reflectance microscopy 
C)  Matrix assisted laser desorption/ionisation-time of flight mass spectrometry 
D)  Cyanin and/or methylene blue endocytotic staining 
E)  Scanning electron microscopy

Question 19

Which of the following characteristics is NOT used to classify bacteria?

Accepted Answer

A)  Size 
B)  Shape 
C)  Colour 
D)  Motility 
E)  Staining 
A)  Size 
B)  Shape 
C)  Colour 
D)  Motility 
E)  Staining

Question 20

Clostridium difficile can be a particularly dangerous bacterium because

Accepted Answer

A)  it produces exospores with a particularly resilient cell wall. 
B)  it has resistance to ampicillin and kanamycin. 
C)  it mutates rapidly. 
D)  it produces endospores, a toxin and has inherent antibiotic resistance. 
E)  it produces exospores, a low pH resistant toxin and can accept multiple plasmids. 
A)  it produces exospores with a particularly resilient cell wall. 
B)  it has resistance to ampicillin and kanamycin. 
C)  it mutates rapidly. 
D)  it produces endospores, a toxin and has inherent antibiotic resistance. 
E)  it produces exospores, a low pH resistant toxin and can accept multiple plasmids.

Exam 35: Bacteria

Why did the first bacteria to evolve use anoxygenic metabolism?

The conversion of CH2O + HCO3 →\rightarrow→ CO2 + CH4 would occur during

Which of the following statements about bacteria is CORRECT?

A bacterium picks up and incorporates some free DNA from its environment, which is then integrated into the bacterial cell. This process is called

A phylogenetic tree of the evolutionary relationships of the different taxa of microorganisms can best be inferred by

Cellular structures to surround the cytoplasm evolved early in the evolutionary history of organisms. These structures were initially beneficial because they

Normal bacterial flora is beneficial to humans and animals because

To generate energy and make sugars, methanogenic bacteria utilise

A bacterial species is discovered in an aquatic, chemically stratified habitat that possesses intracellular Fe minerals. What might be an unusual feature of these bacteria?

The domain Archaea is most closely related to which super kingdom?

A particularly gullible consumer decides to waste his money and buy one of the ubiquitous hand cleaning products that claims to kill 99.9% of germs. Soon after using the product, the poorly informed consumer found that his hands were again teeming with bacteria. This could be because

Compared to the modern age, conditions in the sea 3.5 billion years ago would have been

The major difference between prokaryotes and eukaryotes is that prokaryotes

Early bacteria probably obtained their energy by

A common reference system for classifying bacteria used by taxonomists is

Cyanobacteria are an important subgroup of Bacteria. Which of the statements about cyanobacteria is INCORRECT?

Prokaryotes can be divided into two major lineages: Archaea and Bacteria. Archaea differ from Bacteria in that Archaea

A microbiologist is asked to identify a species of bacteria which is approximately 300nm in diameter. What means would the microbiologist need to use to accurately visualise the bacteria in some detail?

Which of the following characteristics is NOT used to classify bacteria?

Clostridium difficile can be a particularly dangerous bacterium because

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The conversion of CH₂O + HCO₃ $\rightarrow$ CO₂ + CH₄ would occur during