Deck 4: Archaea

Question 1

In which of these aspects do Archaea DIFFER from Eukarya?

A)Histones associated with DNA.
B)The transcription process.
C)The translation process.
D)The replication process.
E)Being haploid in chromosome number while Eukarya are diploid.

Answer 1

E

Question 2

The length of DNA spooled around a histone complex is determined by digesting DNA bound to histones with a DNA endonuclease which forms breaks at unbound DNA sequences,releasing fragments whose size and number reveal the spooled length and overall DNA fragment length.Digestion of an archaeal DNA fragment generated twelve DNA segments.How long was the original DNA?

A)around 300 bp
B)around 500 bp
C)around 800 bp
D)around 5000 bp
E)around 10,000 bp

Answer 2

C

Question 3

Which of these is one of the main functions of the cytoplasmic membrane in Archaea?

A)It protects against effects of differing osmotic pressure
B)It gives the cell its characteristic shapes
C)It acts as a semi permeable barrier to the diffusion of molecules into and out of the cell.
D)It prevents the diffusion of gases into and out of the cell.
E)It allows attachment to specific receptor molecules on solid surfaces in the environment.

Answer 3

C

Question 4

Why might the process of chemotaxis in the archaeon Halobacterium be similar to chemotaxis in Bacteria?

A)Similar proteins in the chemotaxis signaling pathway are found in both Halobacterium and Bacteria.
B)The flagellin protein is almost identical in sequence for both Halobacterium and Bacteria.
C)Genes that encode proteins for flagellum assembly are found in both Halobacterium and Bacteria.
D)Both Halobacterium and Bacteria use ATP to turn the flagellum.
E)Fagellum assembly is identical in both Halobacterium and Bacteria.

Question 5

Some archaeal cells contain pseudopeptidoglycan as their major cell wall component.What is this material composed of?

A)Lipids and proteins.
B)Sugar polymers cross-linked via a peptide bridge.
C)Sugar polymers that are linked to lipids via an ether bond.
D)Proteins liked together via a glycosidic bond.
E)Lipids cross-linked via a peptide bridge.

Question 6

What is the primary reason that Woese and Fox choose the rRNA molecule to study phylogenetic relationships between organisms?

A)Ribosomal RNA is abundant in the cell.
B)Ribosomal RNA is a very stable molecule.
C)Ribosomal RNA is a molecule found in all living organisms.
D)Ribosomal RNA sequencing was very easy to perform at the time.
E)Ribosomal RNA is very easy to isolate and manipulate.

Question 7

What is the size range of a typical Archaea cell?

A))1 - 5 nm
B)20 - 50 nm
C)1 - 5 µm
D)20 - 50 µm
E)1 - 5 mm

Question 8

In which of these are Archaea and Bacteria significantly different?

A)cell size
B)chromosome size and organization
C)lack of a membrane-enclosed nucleus
D)membrane lipid structure
E)possessesion of membrane enclosed organelles

Question 9

Which of these statements is incorrect when describing Archaeal plasma membranes?

A)they all possess a hydrophobic center and hydrophilic surface regions
B)they are all bilayers
C)glycerol 1 phosphate is linked to isoprenes via ether bonds
D)the glycerol phosphate subunits found in the membranes are stereoisomers of those found in Bacterial membranes
E)the glycerol phosphate subunits found in the membranes are stereoisomers of those found in Eukaryal membranes

Question 10

How does the Archaea cytoplasmic membrane differs from the Bacteria membrane?

A)The Archaeal membrane contains cholesterol.
B)The Archaeal membrane contains no proteins.
C)The Archaeal membrane is comprised of fatty acids attached to glycerol phosphate by an ester linkage.
D)The Archaeal membrane is comprised of isoprenoids attached to glycerol phosphate by an ether linkage.
E)The Archaeal membrane gives the cell its characteristic shape.

Question 11

The archaeal chromosome is:

A)linear and contained within a nuclear membrane.
B)circular and contained within a nuclear membrane.
C)circular and contains histones.
D)linear and contains histones.
E)circular,contains histones,and contained within a nuclear membrane.

Question 12

Which of the following is NOT characteristic of the chromosome found in most archaeal cells?

A)The chromosome is made of double stranded DNA.
B)Histones are associated with the chromosome.
C)The chromosome is found in a structure called the nucleoid.
D)The chromosome is found in a single copy.
E)The chromosome is linear.

Question 13

The length of DNA spooled around a histone complex is determined by digesting DNA bound to histones with a DNA endonuclease which forms breaks at unbound DNA sequences,releasing fragments whose size and number reveal the spooled length and overall DNA fragment length.Digestion of an eukaryal DNA fragment generated four DNA segments.How long was the original DNA?

A)50 bp
B)100 bp
C)400bp
D)800 bp
E)2000 bp

Question 14

Which of these statements is correct when describing Archaeal plasma membranes?

A)they are all bilayers
B)they are all monolayers
C)glycerol 3-phosphate is covalently linked to side chains in all membranes
D)glycerol 1-phosphate is covalently linked to side chains in all membranes
E)fatty acid side chains are linked to glycerol

Question 15

How do the Bacteria and Archaea differ in the way the flagellum proteins are handled?

A)Archaea proteins are assembled inside the cell for transport out of the cell.
B)Archaea proteins are excreted to the outside of the cell for self-assembly.
C)Archaea proteins are added to the growing flagellum shaft at the base.
D)Archaea proteins are transported through the hollow flagellum tube for assembly at the end of the flagellum.
E)Archaea proteins are enclosed within a membrane and moved to the outside of the cell.

Question 16

Several Archaea have a lipid monolayer instead of a lipid bilayer comprising their cytoplasmic membrane.Why could this be an advantage?

A)This type of chemical lipid structure is more stable at very high temperatures.
B)Proteins are able to integrate more easily into this type of structure.
C)This type of structure is permeable to protons.
D)Carbohydrates can easily diffuse across this structure to provide nutrients for the cell.
E)This type of structure offers considerable protection against osmotic pressure.

Question 17

Where may a lipid monolayer provide an increased stability over the traditional phospholipid bilayer?

A)in conditions where temperature is elevated
B)in conditions of low pH
C)in conditions of high pH
D)in conditions of low pH and increased temperature
E)in conditions of high pH and increased temperature

Question 18

Which of these is correct regarding subunit rRNA?

A)It serves the same biological function in all organisms.
B)Its sequence changes very slowly over time.
C)It is very stable and easy to work with.
D)It serves the same biological function in all organisms and its sequence changes very slowly over time.
E)These choices are all true.

Question 19

The length of DNA spooled around a histone complex is determined by digesting DNA bound to histones with a DNA endonuclease which forms breaks at unbound DNA sequences between the histone complexes,releasing fragments whose size and number reveal the spooled length and overall DNA fragment length respectively.Digestion of an archaeal DNA fragment generated two DNA segments.How long was the original DNA?

A)200 base pairs
B)500 base pairs
C)800 base pairs
D)2000 base pairs
E)5000 base pairs

Question 20

Synthetic DNA fragments are incubated with either eukaryal histones or archaeal histones.Observation shows that 15 eukaryal histone complexes form along the length of the synthetic DNA.How many archaeal histone complexes would you predict to associate along this DNA?

A)5
B)10
C)20
D)40
E)100

Question 21

Which of these is true about methanogens?

A)They are aerobic and grow on methane.
B)They are anaerobic and ferment methane.
C)They are anaerobic and produce methane from CO₂ reduction.
D)They are aerobic and ferment methane.
E)They are aerobic and produce methane from CO₂ reduction.

Question 22

Archaeans now classified in phylum Thaumarchaeota were previously within the phylum

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

Question 23

To avoid osmotic shock,the obligate halophile Halobacterium salinarum maintains a high intracellular concentration of which chemical?

A)potassium
B)glucose
C)chloride
D)sodium
E)glycine

Question 24

Which combination of bacterial species was most beneficial for weight gain in gnotobiotic mice?

A)Bacteroides,Methanobrevibacter
B)Bacteroides,Desulfovibrio
C)Desulfovibrio,Methanobrevibacter
D)All worked equally well
E)Monocolonization was better for weight gain

Question 25

How many phyla found in the Archaea domain are well-characterized?

A)two
B)eight
C)twelve
D)twenty
E)forty

Question 26

What does Methanobrevibacter smithii use to reduce formate in order to make methane?

A)glucose
B)oxygen
C)nitrogen
D)carbon dioxide
E)hydrogen

Question 27

All known hyperthermophiles possess this enzyme to increase the supercoiling of the DNA and help stabilize it at high temperatures.

A)ligase
B)Taq polymerase
C)thermosome
D)reverse DNA gyrase
E)histone

Question 28

Many of the hyperthermophilic crenarchaeotes that have been grown in culture are also _____ .

A)mesophiles
B)acidophiles
C)barophiles
D)osmolphiles
E)alkalophiles

Question 29

Chaperone proteins in hyperthermophilic archaeal cells are known as

A)chaperonins
B)thermosomes
C)hyperthermosomes
D)desmosomes
E)ribosomes

Question 30

Given the lifestyle of Cenarchaeum symbiosum,how do you hypothesize the marine sponges excrete nitrogenous wastes?

A)as ammonia
B)as uric acid
C)as urea
D)by amino acid elimination
E)none is a correct choice

Question 31

From which area would you be able to isolate the bacterium Halobacterium?

A)the Pacific ocean
B)the Indian ocean
C)Lake Michigan
D)the Great Salt Lake
E)the Mediterranean Sea

Question 32

What does Halobacterium salinarum use the protein bacteriorhodopsin for?

A)proton transfer
B)protection from high salt concentrations
C)sensing light in its environment
D)photosynthesis-like activities
E)sensing nutrient in the environment

Question 33

Which of these is characteristic of a halophile?

A)It grows in a circle on a petri dish.
B)It is extremely small in size.
C)It has an absolute requirement for salt.
D)It requires an acidic environment for growth.
E)It grows only under anaerobic conditions.

Question 34

The secondary structure and amino acid composition of proteins from hyperthermophiles differ somewhat from proteins in mesophile.What would you expect to find in thermophiles?

A)More β-sheets and the amino acids tyrosine and arginine.
B)More α-helices and the amino acids tyrosine and arginine.
C)More β-sheets and the amino acids cysteine and serine.
D)More β-sheets and the amino acids glycine and glutamate.
E)More α-helices and the amino acids cysteine and serine.

Question 35

Many cultured and characterized strains from the phylum Crenarchaeota were isolated from _____ .

A)the ocean
B)freshwater lakes
C)thermal hot springs
D)dry soil
E)sea ice

Question 36

You would be able to find methanogens in all of the following environments EXCEPT:

A)the rumen of bovines.
B)the bottom of a swamp.
C)a well aerated aquifer.
D)sediments from a freshwater lake.
E)the benthic region of the ocean.

Question 37

What are chaperonins ("molecular chaperones")?

A)Channels in the membrane for protein secretion.
B)Proteins used for the secretion of other proteins.
C)Proteins used for the correct folding of other proteins.
D)Proteins involved in the regulation of gene expression at the level of transcription.
E)Sensory proteins found in the cytoplasmic membrane to sense various environmental signals.

Question 38

Which of these observations BEST supports the hypothesis that peptidoglycan in Bacteria and pseudopeptidoglycan in Archaea evolved convergently?

A)NAG is found in glycan strands of both molecules
B)L isomer amino acids are seen in peptide bridges in both molecules
C)The glycosidic bond linkages are different
D)D isomer amino acids are found in peptide bridges in peptidoglycan
E)The physical strength of each cell wall is equivalent

Question 39

What is the minimum salt requirement of a halophile?

A)10 mM
B)100 mM
C)250 mM
D)750 mM
E)1)5 M

Question 40

Some extreme halophiles maintain high internal concentrations of potassium to avoid osmotic shock.What does halophilic bacterial DNA possess that prevents damage from potassium?

A)A novel nucleotide..
B)Their DNA is single stranded instead of double stranded.
C)A high GC content.
D)The DNA is enclosed inside a protective membrane sac.
E)The DNA is protected by high concentrations of magnesium ions.

Question 41

The caption to this figure states that "the linear distance between two samples reflects the likely evolutionary distance between those samples".The linear distances referred to are the vertical line distances.

Question 42

Which of these statements comparing peptidoglycan and pseudopeptidoglyan is correct? (Select all that apply)

A)NAG is found in glycan strands of both molecules
B)L isomer amino acids are seen in peptide bridges in both molecules
C)The physical strength of each cell wall is equivalent
D)D isomer amino acids are seen in peptide bridges in both molecules
E)The glycosidic bond linkages are different

Question 43

Which of these statements comparing peptidoglycan and pseudopeptidoglyan is correct? (Select all that apply)

A)NAG is found in glycan strands of both molecules
B)L isomer amino acids are seen in peptide bridges in both molecules
C)The physical strength of each cell wall is equivalent
D)D isomer amino acids are seen in peptide bridges in both molecules
E)The glycosidic bond linkages are different

Question 44

Given the structure of tyrosine,which of the attributes of thermophile proteins would be influenced by high numbers of tyrosine residues? (Select all that apply)

A)increased alpha helix formation due to increased potential for hydrogen bonding
B)increased salt bridges due to more positive charges on amino acids
C)increased side chain interactions due to increased negative charges on amino acids
D)more transmembrane domains
E)none of these attribute influences can be reliably predicted

Question 45

All members of the phylum Crenarchaeota are hyperthermophiles.

Question 46

Proteins of extreme halophiles contain high amounts of the amino acids _____ and ____ to help stabilize them in high salt environments.

A)arginine,valine
B)aspartate,glutamate
C)glycine,serine
D)histidine,arginine
E)tyrosine,phenylalanine

Question 47

Where do you see new phylogenetic studies in disagreement with the relatedness you might expect from morphological and biochemical comparisons of prokaryotic cells? (Select all that apply)

A)Staphylococcus,Bacillus
B)Thermatoga,Methanothermobacter
C)Staphylococcus,Streptococcus
D)Bacillus,Clostridium
E)Methanococcus,Methanocaldococcus

Question 48

What is the specific action of bacteriorhodopsin?

A)Photosynthesis
B)Assembles ADP and phosphate to make ATP.
C)absorption of light
D)Facilitates the movement of glucose across the cell membrane.
E)Produces proton motive force using light energy.

Question 49

Where have halophiles been isolated from? (Select all that apply)

A)hydrothermal vents
B)temperate environments
C)very cold environments
D)acidic environments
E)alkaline environments

Question 50

Which member of the Archaea domain is a parasite of the archaeon Ignicoccus hospitalis and has one of the smallest genomes of all living microbes?

A)Pyrolobus fumarii
B)Thermoplasma acidophilum
C)Nanoarchaeum equitans
D)Nitrosopumilus maritimus
E)Sulfolobus solfataricus

Question 51

One characterized halophilic archaeal species has an unusual cellular morphology in which cells are flat and square.

Question 52

Given the structure of arginine,which of the attributes of thermophile proteins would be influenced by high numbers of arginine residues? (Select all that apply)

A)increased alpha helix formation due to increased potential for hydrogen bonding
B)increased salt bridges due to more positive charges on amino acids
C)increased side chain interactions due to increased negative charges on amino acids
D)more transmembrane domains
E)none of these attribute influences can be reliably predicted

Question 53

Choose the correct statement(s)regarding Archaeal membrane lipid structure.(Select all that apply)

A)glycerol 3-phosphate is covalently linked to side chains in all membranes
B)glycerol 1-phosphate is covalently linked to side chains in all membranes
C)side chains connected to glycerol include fatty acids
D)side chains connected to glycerol include phytanyl isoprenoid units
E)side chains connected to glycerol include biphytanyl isoprenoid units

Question 54

The Archaea contain a cytoskeleton.

Question 55

The presence of histones in Archaea might lead to the prediction that these cells will: (Select all that apply)

A)Have smaller genomes than Bacteria
B)Have larger genomes than bacteria
C)Have a closer evolutionary relationship with Bacteria than Eukarya
D)Have a closer evolutionary relationship with Eukarya than Bacteria
E)Not use DNA polymerase for chromosome replication

Question 56

All members of the Archaea domain contain a cell wall.

Question 57

Which conclusion might reliably be drawn from the data shown in this figure? (Select all that apply)

A)all Archaeal species evolved through a rapid radiative burst
B)Archaeal species evolved over long periods of times
C)Archaeal divergence from Bacteria took less time than Eukaryal divergence from Archaea
D)Archaea are evolutionarily equidistant from Eukarya and Bacteria
E)All are correct conclusions

Question 58

What detailed rationale(s)might be suggested for Woese's choice of SSU rRNA sequencing to determine phylogenetic relationships? (Select all that apply)

A)the complexity of interactions between ribosomal RNA and transcription proteins make these molecules unlikely to develop random mutations.
B)the complexity of interactions between ribosomal RNA ,ribosomal proteins,mRNAs and tRNAs and make these molecules unlikely to develop random mutations.
C)Due to the position of rRNA genes on the archaeal chromosome,mutation is unlikely to occur
D)The central role in cell survival played by this molecule makes it highly conserved and reliable as a comparative sequence across all life forms.
E)All are valid justifications for woese's choice

Question 59

Choose the correct statement(s)regarding Archaeal membrane lipid functionality.(Select all that apply)

A)the ester linkages found in these lipids are more heat-stable
B)the ether linkages found in these lipids resist oxidative damage
C)the lipid bilayer is thermally more stable
D)the lipid monolayers resist alkaline conditions better
E)the ether linkages found in these lipids resist alkaline conditions

Question 60

Phylum Korarchaeota is little understood and challenging to investigate because:

A)culture conditions for its members have not yet been determined
B)it is a barophile
C)its natural environment is highly inaccessible
D)its alkalophilic growth conditions are unstable
E)all of these choices are correct

Question 61

All known methanogens are found in the domain ___.

Question 62

Members of the archaeal phylum Euryarchaeota are similar in their rRNA gene sequence but differ greatly in their metabolic characteristics.

Question 63

Halobacterium salinarum possess the red-colored protein ___ that absorbs light energy to pump protons across the membrane to create a proton motive force.

Question 64

Most members of the phylum Crenarchaeota that have been isolated and characterized are classified as ___,although environmental DNA samples have shown that these organisms are also present in cold marine environments.

Question 65

Archaeal cells get most of their protection against osmotic pressure differences from their cell _____ .