Deck 19: Bacteria, Archaea, and Viruses

Question 1

The common ancestry (monophyly)of the three domains (Archaea,Bacteria,and Eukarya)is confirmed by

A) the similar appearances of different organisms.
B) ample fossil evidence.
C) DNA as the genetic material that encodes for proteins.
D) the similar sizes of members of all three.
E) the presence of nuclear membranes in all three.

Answer 1

C

Question 2

The Gram method is useful for classifying all bacteria that

A) have two cell membranes.
B) have flagella.
C) have cell walls with at least some peptidoglycan.
D) are prokaryotic.
E) form endospores.

Answer 2

C

Question 3

Archaea is the closest sister group to the

A) bacteria.
B) bacteria and eukaryotes.
C) eukaryotes.
D) prokaryotes.
E) None of the above

Answer 3

C

Question 4

Suppose you are studying an organism with linear chromosomes,few plasmids,and membrane-enclosed organelles.Its lipids are most likely

A) few in number.
B) unbranched.
C) ether-linked.
D) bound to proteoglycan.
E) solid at high temperatures.

Question 5

_______ are more closely related to _______ than they are to _______.

A) Bacteria;Archaea;Eukarya
B) Bacteria;Eukarya;Archaea
C) Archaea;Bacteria;Eukarya
D) Eukarya;Archaea;Bacteria
E) Eukarya;Bacteria;Archaea

Question 6

The domains of life are

A) Fungi,Plants,and Animals.
B) Bacteria,Archaea,and Eukarya.
C) Bacteria,Protists,Fungi,Plants,and Animals.
D) Archaea,Bacteria,Plants,and Animals.
E) Bacteria,Fungi,Plants,Animals,and Humans.

Question 7

Which feature does not belong in the same domain as all of the others?

A) Membrane-enclosed nucleus
B) Ether-linked lipids
C) 80S ribosomes
D) Three RNA polymerases
E) Operons are rare.

Question 8

Which is a basic feature of a prokaryotic cell?

A) Linear DNA chromosomes
B) Nuclear envelope
C) Enzymes for transcription and translation
D) A system for generating GTP
E) Membrane-enclosed organelles

Question 9

Which is not a component of prokaryotic cells?

A) A membrane-enclosed nucleus
B) RNA
C) Ribosomes
D) Circular DNA
E) RNA polymerase

Question 10

Peptidoglycan is a unique feature of the

A) Bacteria.
B) Bacteria and Eukarya.
C) Eukarya.
D) prokaryotes.
E) Archaea and Bacteria.

Question 11

Synthesis of peptidoglycan-containing cell walls is affected by

A) archaea.
B) high toxigenicity.
C) bacteria.
D) antibiotics.
E) Gram stains.

Question 12

Which characteristics or components are distinctive of eukaryotes?

A) Butylmethionine tRNA
B) Cell division by fission
C) Presence of peptidoglycan
D) Membrane-enclosed nucleus
E) Ribosomes

Question 13

The closest monophyletic group(s)to the domain Bacteria is/are

A) Eukarya.
B) Eukarya and Archaea.
C) Archaea.
D) Bacteria and Eukarya.
E) the prokaryotes.

Question 14

The earliest prokaryotic fossils date back at least _______ years.

A) 35,000
B) 350,000
C) 3.5 million
D) 350 million
E) 3.5 billion

Question 15

Which statement about Archaea is false?

A) They live in harsh environments.
B) Their cell walls lack peptidoglycan.
C) Their membrane lipids are different from those in Bacteria.
D) There are similarities in their base sequences of ribosomal RNAs.
E) They are a recently evolved group.

Question 16

Which feature is found in both eukaryotes and prokaryotes?

A) Formylmethionine tRNA
B) A system for generating ATP
C) A nucleus
D) A Golgi apparatus
E) Peptidoglycan in cell walls

Question 17

The common ancestor of all three domains of life probably had

A) membrane-bound organelles.
B) a nucleus.
C) a Golgi apparatus.
D) operons.
E) a circular chromosome.

Question 18

Before they had the ability to decipher nucleotide sequences,biologists classified prokaryotes based on several features,including

A) their nutritional requirements.
B) phenotypic characteristics like shape or color.
C) their antibiotic sensitivity.
D) their modes of locomotion.
E) All of the above

Question 19

You discover a new eukaryote with a novel organelle that includes a circular chromosome and branched membrane lipids.You conclude that this organelle

A) originated from an endosymbiosed member of Archaea.
B) broke away from the nucleus.
C) is a likely target of viruses.
D) probably came from the Proteobacteria.
E) contains a plasmid.

Question 20

You find a single-celled eukaryotic organism that has plasmids,a nucleus,80S ribosomes,and ester-linked unbranched lipids.In what way would this be an unusual eukaryote?

A) Plasmids are rare in eukaryotes.
B) Unbranched lipids are rare in eukaryotes.
C) Ester-linked lipids are only found in bacteria.
D) 80S ribosomes are only found in prokaryotes.
E) Eukaryotes have ether-linked lipids.

Question 21

Which is not a reason that ribosomal RNA (rRNA)is a useful source of data for studying evolutionary relationships?

A) rRNA undergoes a high degree of lateral transfer.
B) No free-living organism lacks rRNA.
C) rRNA plays a critical role in the translation process in all organisms.
D) rRNA evolves slowly,so it can be analyzed across a wide range of organisms.
E) rRNA is evolutionarily ancient and was present in the common ancestor of all life forms.

Question 22

The _______ are Gram-positive bacteria including those that cause tuberculosis and those that produce streptomycin.Most antibiotics come from bacteria in this group.

A) cyanobacteria
B) spirochetes
C) chlamydias
D) actinobacteria
E) proteobacteria

Question 23

You perform chemical analysis of a fossil,which shows that some decay occurred before fossilization.There is also evidence of peptidoglycan.The most likely conclusion about the decay is that it was due to

A) digestion by an animal.
B) the action of bacteria.
C) the action of archaeans.
D) the action of fungi.
E) some cause that cannot be determined.

Question 24

The division of the living world into three domains

A) is based on the number of cells in organisms of each group.
B) is based mostly on the major morphological differences between archaea and bacteria.
C) reflects the great importance of eukaryotes.
D) was proposed after the invention of the first microscope.
E) is based on phylogenetic relationships determined from nucleotide sequences of rRNA and other genes.

Question 25

Which statement about bacteria is true?

A) Gram-positive bacteria have a lot of peptidoglycan in their cell walls and stain blue to purple.
B) Gram-negative bacteria have no peptidoglycan in their cell walls and stain blue to purple.
C) Gram-positive bacteria weigh more than a gram.
D) Gram-positive bacteria have relatively little peptidoglycan in their cell walls and stain pink to red.
E) Gram-negative bacteria lack a cell membrane.

Question 26

How are prokaryote phylogenies different from mammal phylogenies?

A) There is a high degree of lateral gene transfer in mammals.
B) Mammal phylogenies are constructed from evidence based in DNA,whereas prokaryote phylogenies are based in RNA.
C) There is a high degree of lateral gene transfer in prokaryotes.
D) The phylogenetic reconstruction process is much simpler for prokaryotes because they are much smaller.
E) Mammals have transposons.

Question 27

Bacteria may differ from one another in their

A) structure.
B) metabolism.
C) life cycle.
D) DNA content.
E) All of the above

Question 28

A consensus tree consists of a cladogram

A) based on morphological characteristics.
B) that summarizes evolutionary relationships among organisms using data from multiple different gene sequences.
C) showing lateral gene transfer for a single gene.
D) showing the evolutionary relationships among organisms based on a single DNA sequence.
E) based on molecular and biochemical features.

Question 29

Mycoplasmas

A) contain less DNA than most other prokaryotes.
B) have peptidoglycan in their cell walls.
C) form a branched,filamentous mycelium.
D) possess elaborate internal membrane systems.
E) can be controlled by penicillin.

Question 30

Genes that are likely to undergo lateral transfer are those that

A) are involved in antibiotic resistance.
B) confer no fitness advantage to the recipient.
C) are highly conserved and involved in DNA replication.
D) are longer than average.
E) code for metabolic functions.

Question 31

If a few genes from Mycobacterium are discovered to be part of the circular chromosome of Streptomyces,one can conclude that _______ took place.

A) sideways transfer
B) endosymbiosis
C) hybridization
D) lateral gene transfer
E) plasmid exchange

Question 32

Lateral gene transfer is the process by which

A) scientists make transgenic organisms.
B) prokaryotes within a species exchange genes.
C) prokaryotes acquire DNA from a different species.
D) genes are passed to daughter cells.
E) prokaryotes recombine different versions of a gene.

Question 33

Which statement about endospores is true?

A) More than one endospore can be produced by each parent cell.
B) Endospores can survive harsh environmental conditions.
C) Endospores contain some cytoplasm but not nucleic acid.
D) Endospores are enclosed within two soft cell walls.
E) An endospore is a reproductive structure.

Question 34

_______ can produce heat-resistant endospores.

A) Cyanobacteria
B) Spirochetes
C) Chlamydias
D) Proteobacteria
E) Firmicutes

Question 35

The sequencing of rRNA allowed scientists to understand

A) the clear relationships among different prokaryotic species.
B) that certain nucleic acid sequences are unique to archaea and eukarya.
C) that archaea are similar to bacteria.
D) that all DNA is relatively the same.
E) that half of the sequences of archaea were previously unknown.

Question 36

While working on a cell sample from a sick cow,you notice a number of very small bacteria in the cells.What is the best conclusion about the role of the bacteria in the cow's cells?

A) They developed as a resistance against the disease but were ineffective.
B) They are mycoplasmas that are causing the disease.
C) They are endosymbionts evolving into a new kind of mitochondria.
D) They are neither helping nor hurting the cow.
E) They are actually misidentified mitochondria.

Question 37

If you boil water,can you be sure that it will be free of living prokaryotes?

A) Yes;boiling kills all organisms.
B) Yes;prokaryote DNA degrades at high temperatures.
C) No;some prokaryotes can live at boiling temperatures.
D) Yes,since no known bacteria can survive boiling.
E) Yes,because bacteria must have a eukaryotic host,and no eukaryote survives boiling.

Question 38

Low-GC Gram-positive bacteria

A) do not constitute a monophyletic clade.
B) include Rhizobium.
C) can reproduce only within the cells of other organisms.
D) all possess structures called axial filaments.
E) include the important genera Bacillus and Clostridium.

Question 39

You analyze bacterial samples from a toxic waste dump and find that one bacterial colony is able to survive exposure to nuclear radiation.To what group would that colony most likely belong?

A) Cyanobacteria
B) Spirochetes
C) Chlamydias
D) Proteobacteria
E) Hadobacteria

Question 40

The space between the outer membrane and the cell membrane of a Gram-negative bacterium is called the _______ space.

A) enzymatic
B) negative
C) perimembrane
D) periplasmic
E) resistance

Question 41

Which habitats would be favored by thermoacidophiles?

A) The stomachs of many herbivores
B) Hot,alkaline springs
C) Anaerobic conditions
D) Hot sulfur springs
E) Deep-sea volcanic vents

Question 42

Suppose you are building an artificial hot spring in your yard.The water is hot and mineral-rich,but it doesn't have the bright colors seen in natural hot springs.To get those bright colors,you could allow the growth of

A) cyanobacteria.
B) mycoplasmas.
C) crenarchaeotes.
D) proteobacteria.
E) spirochetes.

Question 43

_______ are small intracellular parasites that have a unique,complex reproductive cycle and include strains that cause eye infections and venereal disease.

A) Chlamydias
B) Spirochetes
C) Cyanobacteria
D) Proteobacteria
E) Actinobacteria

Question 44

Which pair includes two members that involve DNA transfer by prokaryotes?

A) Lateral gene transfer and crown gall
B) Crown gall and virus formation
C) Lateral gene transfer and virus formation
D) Crown gall and biofilm formation
E) Biofilm formation and lateral gene transfer

Question 45

Which characteristic or component is distinctive to archaea?

A) Unique genes not found in other domains
B) Branched,long-chain hydrocarbons
C) A lack of peptidoglycan
D) Lipids with glycerol-ether linkages
E) All of the above

Question 46

_______,which include the bacterium that causes syphilis,use axial filaments to move.

A) Cyanobacteria
B) Spirochetes
C) Chlamydias
D) Proteobacteria
E) Actinobacteria

Question 47

Spirochetes move via

A) gas vesicles.
B) cilia.
C) axial filaments.
D) pseudopods.
E) flagella.

Question 48

Which statement about spirochetes is true?

A) They are all free-living.
B) They are all parasites of other bacteria.
C) They can form chains of cells.
D) They all possess structures called terminal filaments.
E) They are spiral-shaped bacteria.

Question 49

Actinobacteria

A) are photoheterotrophs.
B) are the only bacteria that divide by mitosis.
C) are Gram-negative bacteria.
D) were once classified as protists.
E) are the source of many important antibiotics.

Question 50

The size of the smallest bacterium is _______ $\mu$ m.

A) 0.2
B) 2
C) 7.5
D) 75
E) 750

Question 51

Cyanobacteria

A) are a diverse and unrelated group of bacteria.
B) use chlorophyll a and release oxygen during photosynthesis.
C) are the only group of photosynthetic bacteria.
D) can reproduce sexually.
E) are obligate aerobes.

Question 52

The best place to look for a new,heat-tolerant DNA polymerase enzyme would be among the

A) thermophilic archaea.
B) methanogens.
C) extreme halophiles.
D) spirochetes.
E) proteobacteria.

Question 53

Chlamydias

A) can form heterocysts.
B) form a branched,filamentous mycelium.
C) contain less DNA than any other organism.
D) can live only within the cells of other organisms.
E) were once classified as fungi.

Question 54

Which sequence represents the correct chronological order of events in the life of a Gram-positive bacterium?

A) Endospore formation,low-nutrient stress,endospore germination,breakdown of parent cell
B) Low-nutrient stress,endospore formation,breakdown of parent cell,endospore germination
C) Endospore formation,endospore germination,breakdown of parent cell,low-nutrient stress
D) Low-nutrient stress,endospore germination,breakdown of parent cell,endospore formation
E) Endospore germination,breakdown of parent cell,low-nutrient stress,endospore formation

Question 55

You are given a mixed sample of Bacteria and Archaea and asked to identify which more specific groups are present.When you try culturing portions of the sample under different conditions,freshwater cultures at room temperature turn blue-green and cultures in high salt become dark purple.Which groups must be present in the mixed sample?

A) Cyanobacteria and extreme halophiles
B) Extreme halophiles and proteobacteria
C) Proteobacteria and euryachaeota
D) Chlamydias and cyanobacteria
E) Chlamydias and proteobacteria

Question 56

Which bacterial group includes the greatest number of species?

A) Chlamydia
B) Proteobacteria
C) Actinobacteria
D) Mycoplasmas
E) Cyanobacteria

Question 57

The chlorophyll of cyanobacteria is

A) bacteriorhodopsin.
B) distinct from the chlorophyll of plants.
C) bacteriochlorophyll.
D) like that of plants.
E) rarely produced.

Question 58

Which group of prokaryotes was responsible for converting Earth's early atmosphere from anaerobic to aerobic?

A) Proteobacteria
B) Halophiles
C) Cyanobacteria
D) Spirochetes
E) Actinobacteria

Question 59

_______ contain photosynthetic lamellae and photosynthesize using chlorophyll a.

A) Proteobacteria
B) Spirochetes
C) Chlamydias
D) Cyanobacteria
E) Firmicutes

Question 60

Some cyanobacteria that form filamentous colonies possess heterocysts,which are

A) a means of locomotion.
B) infectious.
C) the resting stage for the cyanobacteria.
D) endospores.
E) cells specialized for nitrogen fixation.

Question 61

An ecosystem based on chemoautotrophs exists 2,500 meters below the ocean surface near the Galápagos Islands.These archaea

A) use light as energy and obtain carbon from carbon dioxide.
B) use light as energy and obtain organic compounds from other organisms.
C) oxidize inorganic substances for energy and obtain carbon from carbon dioxide.
D) rely on organic compounds for both energy and carbon.
E) oxidize organic compounds for energy and obtain carbon from carbon dioxide.

Question 62

If numerous microbes that inhabit in the human body were destroyed,either because of use of medications or environmental influences,the likely effect would be

A) improved health in the general population.
B) a decline in people's health.
C) the prevention of all infectious diseases.
D) the destruction of pathogenic bacteria only.
E) the eradication of most human diseases.

Question 63

Suppose you are given unlabeled cultures of colonies of cyanobacteria and purple sulfur bacteria.How can you use an obligate aerobic eukaryotic organism to test which colonies are which?

A) Add the aerobe to each culture;cyanobacteria will be toxic to other organisms.
B) Add the aerobe to each culture;purple sulfur bacteria will be toxic to other organisms.
C) Add the aerobe to each culture;cyanobacteria will provide the required oxygen if allowed to photosynthesize.
D) Add the aerobe to each culture;purple sulfur bacteria will provide the required oxygen if allowed to photosynthesize.
E) The aerobe cannot be used to test which colonies are which.

Question 64

Methanogenic euryarchaeotes are obligate anaerobes,some of which live in the intestinal tracts of mammals and other animals.From this information,one can conclude that the environment in the intestinal tracts

A) is rich in oxygen.
B) is rich in sulfur.
C) lacks oxygen.
D) lacks methane.
E) contains termites.

Question 65

Which statement about the biofilm found in the human large intestine is false?

A) It is made up of numerous species of toxic bacteria.
B) It facilitates nutrient transfer from the intestine to the body.
C) It is essential for human health.
D) Its exact species makeup varies from region to region.
E) Humans get vitamins B₁₂ and K from the bacterial waste products.

Question 66

Organisms that derive their carbon only from other organisms are called

A) autotrophs.
B) herbivores.
C) heterotrophs.
D) photosynthetic.
E) protists.

Question 67

Which statement about nitrogen metabolism is false?

A) Certain prokaryotes reduce atmospheric N₂ to ammonia.
B) Some nitrifiers are soil bacteria.
C) Denitrifiers are obligate anaerobes.
D) Nitrifiers obtain energy by oxidizing ammonia and nitrite.
E) Without nitrifiers,terrestrial organisms would lack a nitrogen supply.

Question 68

All photosynthetic prokaryotes

A) use chlorophyll a as their photosynthetic pigment.
B) use bacteriochlorophyll as their photosynthetic pigment.
C) release oxygen gas.
D) are photoautotrophs.
E) produce particles of sulfur.

Question 69

Which term does not relate to a prokaryote's metabolic diversity?

A) Aerotolerant
B) Anaerobic
C) Photoautotroph
D) Lateral transfer
E) Nitrogen fixing

Question 70

Prokaryotes,along with fungi,return tremendous quantities of organic carbon to the atmosphere as

A) ATP.
B) CO₂.
C) carbon monoxide.
D) energy.
E) nitrogen gas.

Question 71

Which nutritional category of prokaryotes can exist independently of other organisms?

A) Photoautotrophs
B) Photoheterotrophs
C) Photochemotrophs
D) Chemoheterotrophs
E) None of the above

Question 72

Which statement about methanogens is false?

A) Some are thermophilic.
B) They are associated with mammalian flatulence.
C) They prefer anaerobic conditions.
D) Methane is their preferred carbon source.
E) They are closely related to the extreme halophiles.

Question 73

Which of the following is not an example of a biofilm?

A) Plaque on a tooth
B) Coating on contact lenses
C) Layers in an ancient stromatolite
D) Coating on a metal pipeline in a steam plant
E) Bacteria on root nodules

Question 74

Most bacteria are

A) photoautotrophs.
B) photoheterotrophs.
C) chemoautotrophs.
D) chemoheterotrophs.
E) disease-causing.

Question 75

Most prokaryotes

A) are agents of disease.
B) lack ribosomes.
C) evolved from the most ancient eukaryotes.
D) lack a cell wall.
E) are chemoheterotrophs.

Question 76

Bacteria are known for the many roles they play in biological communities.Which is the rarest role for this group of organisms?

A) Pathogen
B) Digestive aid
C) Nitrogen and sulfur processor in soils
D) Decomposer
E) Industrial and agricultural use

Question 77

In light,purple sulfur bacteria use H₂S as an electron donor and release pure sulfur as a waste product.They are examples of

A) photoautotrophs.
B) photoheterotrophs.
C) chemoautotrophs.
D) chemoheterotrophs.
E) deep-sea,volcanic vent bacteria.

Question 78

All prokaryotes that use light as an energy source

A) use chlorophyll a as their photosynthetic pigment.
B) use bacteriochlorophyll as their photosynthetic pigment.
C) release oxygen gas.
D) produce particles of sulfur.
E) store the energy of light rather than using it immediately.

Question 79

Bacteria have a role in

A) animal digestion.
B) the processing of nitrogen and sulfur in soils.
C) decomposition in all ecosystems.
D) many industrial and commercial processes.
E) All of the above

Question 80

Which of the following is a broad nutritional category of prokaryotes that is recognized by biologists?

A) Physioautotrophs
B) Heterolithotrophs
C) Obligate aerobes
D) Chemoautotrophs
E) Obligate anaerobes