Deck 19: Archaeal Diversity

Question 1

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 1

B

Question 2

Which division is the most divergent from the rest?

A) Crenarchaeota
B) Euryarchaeota
C) Thaumarchaeota
D) Ancient Archaeal Group
E) all the above are about the same

Answer 2

D

Question 3

The cross-bridges of __________ are sensitive to penicillin.

A) peptidoglycan
B) pseudopeptidoglycan
C) S-layer
D) protein cell wall
E) all of the above

Answer 3

A

Question 4

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

A) crenarchaeotes
B) euryarchaeotes
C) Ancient Archaeal Group
D) nanoarchaeotes
E) methanogens

Question 5

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

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

Question 6

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

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

Question 7

Archaeal histones are found in __________ such as methanogens.

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

Question 8

__________-branched chains increase membrane stability.

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

Question 9

Archaeal membranes contain __________ lipid side chains.

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

Question 10

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 11

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

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

Question 12

Another scientist has given you a culture of an archaeon 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 13

Nanoarchaeaum equitans is a(n) __________ symbiont of a crenarchaeote.

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

Question 14

Which of the following is NOT found in nearly all archaea?

A) S-layer
B) isoprenoid chains
C) L-glycerol
D) crenarchaeol
E) ether-linked lipids

Question 15

Which of the following species is aerobic?

A) Aeropyrum
B) Thermococci
C) Thermosphera
D) all of the above
E) none of the above

Question 16

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 17

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 18

The __________ domain lacks pathogens.

A) Eukarya
B) Bacteria
C) Archaea
D) protist
E) monera

Question 19

Archaeosine is a guanine analog found in archaeal:

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

Question 20

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

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

Question 21

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 22

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 23

The thaumarcheal ammonia oxidizers contribute to the global cycling of:

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

Question 24

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

A) equivalent to
B) higher than
C) lower than
D) variable enough that it cannot be measured against
E) none of the above

Question 25

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 26

Which of the following best describes the Thaumarchaeota?

A) They are extremophiles that live in hydrothermal vents.
B) They contain mesophilic marine ammonia oxidizers.
C) They contain symbionts of sponges.
D) A and B.
E) B and C.

Question 27

Bovine __________ not only make a significant contribution to global methane, they also divert carbon from meat production.

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

Question 28

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

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

Question 29

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

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

Question 30

__________ influence the fermentation efficiency of the gut flora.

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

Question 31

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 32

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 33

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 34

Methanogens are classified within how many major orders?

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

Question 35

Which is the model haloarchaeon?

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

Question 36

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

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

Question 37

Which of the following uses light to generate a proton gradient in the haloarchaeotes?

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

Question 38

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 39

Nitrosopumilus maritimus is able to oxidize:

A) nitrate
B) ammonia
C) sulfide
D) sulfate
E) methane

Question 40

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 41

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 42

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 43

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

Question 44

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

Question 45

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 46

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 47

Nanoarchaeum equitans is a hyperthermophilic symbiont of:

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

Question 48

Why are extremophiles important to industry?

Question 49

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 50

Why are the archaea so difficult to classify?

Question 51

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

Question 52

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 53

Crenarchaeol is a biosignature for Thaumarchaeota. Describe its structure.

Question 54

Haloarchaea can regulate their buoyancy through the production of:

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

Question 55

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

Question 56

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

Question 57

Laboratory isolation of Nanoarchaeum equitans requires the presence of:

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

Question 58

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 59

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 60

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

Question 61

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

Question 62

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

Question 63

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

Question 64

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

Question 65

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

Question 66

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

Question 67

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

Question 68

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

Question 69

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

Question 70

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

Question 71

Explain how ammonia-oxidizing Thaumarchaeota gain energy and what habitats they are found in.