Deck 19: Archaeal Diversity

Question 1

Archaeosine is a guanine analog found in archaeal __________.

A) rRNA
B) mRNA
C) DNA
D) msRNA
E) tRNA

Answer 1

E

Question 2

__________ is sensitive to penicillin.

A) Peptidoglycan
B) Pseudopeptidoglycan
C) S-layer
D) Protein cell wall
E) all of the above

Answer 2

A

Question 3

Which organism has a periplasmic space containing membrane vesicles?

A) Desulfurococcus sp.
B) Ignicoccus sp.
C) Methanosarcina sp.
D) Methanothermus sp.
E) Pyrodictium sp.

Answer 3

B

Question 4

Which archaea has/have retinal-associated, light-driven membrane pumps for H⁺ or Na⁺?

A) all archaea
B) hyperthermophilic Crenarchaeota
C) Methanobacteriales
D) Haloarchaea
E) Sulfolobales

Question 5

The Haloarchaea, extreme __________, are the only form of life to grow in concentrated brine.

A) thermophiles
B) psychrophiles
C) methanophiles
D) halophiles
E) acidophiles

Question 6

Which of the following is NOT a phylum among the archaea?

A) Crenarchaeota
B) Euryarchaeota
C) Methanoarchaeota
D) Nanoarchaeota
E) Korarchaeota

Question 7

Archaeal histones are found in __________ such as the methanogens.

A) euryarchaeota
B) crenarchaeota
C) korarchaeota
D) nanoarchaeota
E) halophiles

Question 8

With respect to pH, the __________ show the widest range of any clade.

A) crenarchaeotes
B) euryarchaeotes
C) korarchaeotes
D) nanoarchaeotes
E) methanogens

Question 9

Another scientist has given you a culture of an archaea that is an extreme thermophile and is an obligate anaerobe. It does not produce methane and will not grow under high salt conditions or in very acidic conditions. What group does this organism belong to?

A) Nanoarchaeota
B) Crenarchaeota
C) methanogens
D) extreme halophiles
E) Thermoplasmatales

Question 10

__________ is a glycerol diphytanyl diether containing a six-membered cyclic ring.

A) Crenarchaeol
B) Euryarchaeol
C) Nanoarchaeol
D) Korarchaeol
E) Methanoarchaeol

Question 11

Which of the following is unique to archaea?

A) pseudopeptidoglycan
B) S-layers
C) supercoiled DNA
D) infection by double-stranded DNA viruses
E) methanotrophs

Question 12

Some archaea contain genomes with positive superturns generated by __________, which protect DNA from extreme acid.

A) helicase
B) polymerase
C) primase
D) reductase
E) reverse gyrase

Question 13

The side chains of archaeal lipids are branched at every __________ carbon.

A) first
B) second
C) third
D) fourth
E) fifth

Question 14

Which division shows the most divergence?

A) Crenarchaeota
B) Euryarchaeota
C) Nanoarchaeota
D) Korarchaeota
E) All the above are about the same

Question 15

The __________ domain lacks pathogens.

A) eukarya
B) bacteria
C) archaeal
D) protist
E) monera

Question 16

__________ branched chains increase membrane stability.

A) Isoprenoid
B) Ester
C) Ether
D) Diether
E) Phospholipid

Question 17

Archaeal membranes contain __________ lipid side chains.

A) glycoprotein
B) retinal
C) isoprenoid
D) diether
E) ester

Question 18

The energy-yielding process of __________ occurs only in the archaea.

A) fermentation
B) sulfur oxidation
C) hydrogen oxidation
D) methanogenesis
E) anaerobic respiration

Question 19

Which of the following is NOT found in archaeal S-layers?

A) glycoprotein
B) methanochondroitin
C) protein
D) pseudomurein
E) sulfated polysaccharide

Question 20

The Nanoarchaeota is represented by a __________ symbiont of a crenarchaeote.

A) methanogenic
B) halophilic
C) psychrophilic
D) acidophilic
E) hyperthermophilic

Question 21

Bovine __________ not only makes a significant contribution to global methane, it also diverts carbon from meat production.

A) halophiles
B) acidophiles
C) autotrophs
D) thermophiles
E) methanogenesis

Question 22

The crenarchaeote ammonia oxidizers contribute to the global cycling of __________.

A) phosphorus
B) nitrogen
C) sulfur
D) oxygen
E) hydrogen

Question 23

Which of the following classes contains organisms that are psychrophiles?

A) Thermoprotei
B) Thermococci
C) Thermoplasmata
D) all of the above
E) none of the above

Question 24

Which of the following contains saturated salts of essentially the same proportions as the ocean?

A) thalassic lakes
B) athalassic lakes
C) solar salterns
D) undersea brine pools
E) underground salt deposits

Question 25

__________ influence the fermentation efficiency of the gut flora.

A) Pathogens
B) Bacteria
C) Eukarya
D) Methanogens
E) Halophiles

Question 26

Sulfolobus species are referred to as double __________, meaning they require high temperature and high acidity simultaneously.

A) extremophiles
B) thermophiles
C) acidophiles
D) hyperthermophiles
E) thermoacidophiles

Question 27

Methanogenesis includes a unique pathway of carbon fixation, called the carbon monoxide __________ pathway, because the key enzyme can fix CO as well as CO₂.

A) gyrase
B) helicase
C) polymerase
D) reductase
E) dismutase

Question 28

Commercial evaporation pools for salt production benefit from the presence of red __________, whose light absorption accelerates heating and evaporation.

A) methanogens
B) Sulfolobus
C) acidophiles
D) haloarchaea
E) thermophiles

Question 29

The __________ species secretes toxins deadly to other strains of the same species.

A) Sulfolobus
B) Halobacterium
C) Nanoarchaeum
D) Methanococcus
E) Thermoplasma

Question 30

Which of the following coenzymes is NOT specific for methanogenesis?

A) methanofuran (MFR)
B) tetrahydromethanopterin (H₄MPT)
C) cofactor F₄₂₀ (F₄₂₀)
D) nicotinamide adenine dinucleotide (NAD⁺)
E) coenzyme M (CoM)

Question 31

Methanogens are classified within how many orders?

A) one
B) two
C) three
D) four
E) five

Question 32

Haloarchaea can regulate their buoyancy through the production of __________.

A) contractile vacuoles
B) pigments
C) salt
D) gas vesicles
E) carbon dioxide

Question 33

Which is the model haloarchaeon?

A) Haloarcula
B) Haloquadra
C) Halorubrum
D) Halobacterium
E) Halococcus

Question 34

In wastewater, the bacteria are packed together by filamentous __________ to form sludge.

A) halophiles
B) thermophiles
C) methanogens
D) psychrophiles
E) acidophiles

Question 35

The major environmental location of methanogens is:

A) landfills
B) ruminant digestive tracts
C) human digestive tracts
D) anaerobic wetlands soil
E) marine floor sediment

Question 36

In methanogenesis from CO₂ and H₂, the initial incorporation of H₂ requires a coupled gradient of which ion?

A) sodium
B) potassium
C) iron
D) magnesium
E) molybdenum

Question 37

Which of the following Crenarchaeota grows as disks linked by cannulae?

A) Aeropyrum pernix
B) Desulfurococcus mobilis
C) Ignicoccus islandicus
D) Thermosphaera aggregans
E) Pyrodictium brockii

Question 38

The Sulfolobus species maintains an internal pH __________ that of its habitat.

A) equivalent to
B) higher than
C) lower than
D) equal to
E) none of the above

Question 39

Members of the __________ possess no cell wall at all.

A) Euryarchaeota
B) Crenarchaeota
C) Korarchaeota
D) Nanoarchaeota
E) Halophiles

Question 40

In methanogenesis from CO₂ and H₂, __________ is hydrogenated and deoxygenated in a stepwise fashion.

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

Question 41

Why are extremophiles important to industry?

Question 42

Explain why, when growing Halobacterium on agar plates, some colonies may be pink, some red, and some sectored.

Question 43

Most organisms of which of the following orders lack both a cell wall and an S-layer?

A) Archaeoglobales
B) Thermoplasmatales
C) Halobacteriales
D) Methanobacteriales
E) Methanococcales

Question 44

Compare and contrast the supercoiling in hyperthermophilic archaeal species with bacteria and eukaryotes. What is responsible for this feature and what does it accomplish for these archaea?

Question 45

Why are the archaea so difficult to classify?

Question 46

Crenarchaeol is a biosignature for crenarchaeotes. Describe its structure.

Question 47

Nanoarchaeum equitans is a hyperthermophilic symbiont of __________.

A) Ignicoccus
B) Sulfolobus
C) Halobacterium
D) Methanococcus
E) Thermoplasma

Question 48

Why are hot springs and geysers important habitats for many crenarchaeotes?

Question 49

Laboratory isolation of Nanoarchaeum equitans requires the presence of

A) fatty acids
B) oxygen
C) Ignicoccus
D) sunlight
E) horse cell culture

Question 50

What are some of the unique features of archaeal gene regulation?

Question 51

Why has Sulfolobus been studied so much more extensively than many archaea and what is known about it?

Question 52

Archaeoglobus fulgidus conserves energy by sulfate respiration, which drives a unique acetyl-CoA degradation pathway involving the reversal of __________.

A) methanogenesis
B) glycolysis
C) flagella rotation
D) TCA cycle
E) electron transport

Question 53

Describe the different branched chain lipids that are characteristic of archaeal membranes.

Question 54

In the haloarchaea, the red pigment bacterioruberin protects cells from damage by __________.

A) light
B) salt
C) heat
D) acid
E) cold

Question 55

Which of the following is responsible for movement away from DNA-damaging light?

A) bacteriorhodopsin
B) halorhodopsin
C) sensory rhodopsin I
D) sensory rhodopsin II
E) sensory rhodopsin III

Question 56

Describe some of the unique metabolic pathways found in Archaea but not Bacteria or Eukarya.

Question 57

Bacteriorhodopsin absorbs light and pumps H⁺ __________ the cell, whereas light-activated halorhodopsin pumps chloride __________ the cell.

A) into; out of
B) out of; into
C) into; into
D) out of; out of
E) through; across

Question 58

Which of the following is an extreme acidophile found anchored to deposits of pyrite within the Iron Mountain Mine?

A) Thermus aquaticus
B) Pyrococcus abyssi
C) Ferroplasma acidarmanus
D) Picrophilus torridus
E) Thermoplasma acidophilum

Question 59

All of the rhodopsins in the haloarchaeotes have how many alpha helical transmembrane domains?

A) one
B) three
C) five
D) seven
E) nine

Question 60

Which of the following provides the red coloration of the haloarchaeotes?

A) bacteriorhodopsin
B) bacterioruberin
C) halorhodopsin
D) methanofuran
E) ferredoxin

Question 61

What is the Ancient Archaeal Group and what is known about these organisms?

Question 62

Describe some of the environments in which haloarchaea are found. What are the differences in these environments?

Question 63

What are "vent polymerases," why are they better than previously used polymerases, and from where are they acquired?

Question 64

What are some of the components and products of haloarchaea that can potentially be used in industry and research?

Question 65

What are methane gas hydrates and where are they found? Discuss the idea of benthic mining.

Question 66

Where are methanogens found in nature? What are some of the problems they can cause in these habitats?

Question 67

Discuss the role of the four different types of rhodopsins found in the Halobacterium species (bacteriorhodopsin, halorhodopsin, and sensory rhodopsins I and II).

Question 68

Describe the physiological adaptations found in haloarchaea that compensate for the high internal potassium chloride concentrations.

Question 69

Discuss the genome and morphology of known archaeal viruses. Why are their genomes all similar in structure?

Question 70

If archaea are distinct from bacteria, why is the major haloarchaeal order called Halobacteriales and why do most contain bacteriorhodopsin?