MBIO 3401 TTU EXAM QUESTIONS AND
ANSWERS | WITH COMPLETE SOLUTION
What is the metagenome?
The sum total of all DNA in an environmental sample.
What is the small subunit (SSU) rRNA sequence?
The standard for identifying environmental taxa.
How are microbes identified?
Compare SSU rRNA
What is the SSU rRNA for prokayotes?
16S rRNA
What is the SSU rRNA for eukaryotes?
18S rRNA
What are operational taxonomic units (OTUs)?
A working metagenomic definition of "species"
What is a rarefaction curve?
Plots out the OTUs (species) as a function of increasing sample size.
Ending "-ales" of bacteria typically indicates...
Bacterial order
What are the loop sites on bacterial 16S rRNA?
,Sites that are free to mutate and evolve faster.
What are the stem sites on bacterial 16S rRNA?
Sites that rarely mutate and are conserved.
What are deep-branching thermophiles?
Bacteria that diverged earliest from ancestral archaea.
Fastest doubling rates of all cells.
High mutation rate.
What are the deep-branching thermophiles?
Chloroflexi
Deinococcus-Thermus
Chloroflexi:
Photoheterotrophic, moderate thermophile
Green nonsulfur bacteria
Contain chlorosomes
Forms filamentous mats with cyanobacteria.
Deinococcus-Thermus (phylum)
Contain ornithine (amino acid) in peptidoglycan cross-bridges.
Thermus (species)
Moderate thermophiles
Heterotrophs
,Deinococcus (species)
Not thermophilic
Resistant to high radiation/desiccation
Thick cell wall and S-layer
What are cyanobacteria?
Only oxygenic phototrophic prokaryotes.
(contain chlorophyll/pigments)
Photosynthesis in the thylakoids
Fix CO2 in carboxysomes
Float with gas vesicles
Fix N2 in heterocysts
What are the phylum of Gram +?
Firmicutes (low GC) and Actinobacteria (high GC)
Contain thick cell walls, reinforced by teichoic acids.
What are the spore-forming firmicutes?
, Bacillus and Clostridium
What are some examples of bacillus?
B. anthrax (anthrax)
B. thuringiensis (organic insect repellant that makes Cry toxins)
B. subtilis ("model organism")
Why would a vegetative cell create endospores?
Unfavorable conditions cause the creation of spores
What are some examples of clostridium?
C. botulinum
C. tetani
C. difficile
Endospores swell, form drumstick appearance.
What are the non-spore-forming firmicutes?
(not all bacillales and clostridiales)
Lactic acid bacteria (aerotolerant)
-Lactococcus
-Lactobacillus
-Leuconostoc
What are the pathogenic firmicutes?
ANSWERS | WITH COMPLETE SOLUTION
What is the metagenome?
The sum total of all DNA in an environmental sample.
What is the small subunit (SSU) rRNA sequence?
The standard for identifying environmental taxa.
How are microbes identified?
Compare SSU rRNA
What is the SSU rRNA for prokayotes?
16S rRNA
What is the SSU rRNA for eukaryotes?
18S rRNA
What are operational taxonomic units (OTUs)?
A working metagenomic definition of "species"
What is a rarefaction curve?
Plots out the OTUs (species) as a function of increasing sample size.
Ending "-ales" of bacteria typically indicates...
Bacterial order
What are the loop sites on bacterial 16S rRNA?
,Sites that are free to mutate and evolve faster.
What are the stem sites on bacterial 16S rRNA?
Sites that rarely mutate and are conserved.
What are deep-branching thermophiles?
Bacteria that diverged earliest from ancestral archaea.
Fastest doubling rates of all cells.
High mutation rate.
What are the deep-branching thermophiles?
Chloroflexi
Deinococcus-Thermus
Chloroflexi:
Photoheterotrophic, moderate thermophile
Green nonsulfur bacteria
Contain chlorosomes
Forms filamentous mats with cyanobacteria.
Deinococcus-Thermus (phylum)
Contain ornithine (amino acid) in peptidoglycan cross-bridges.
Thermus (species)
Moderate thermophiles
Heterotrophs
,Deinococcus (species)
Not thermophilic
Resistant to high radiation/desiccation
Thick cell wall and S-layer
What are cyanobacteria?
Only oxygenic phototrophic prokaryotes.
(contain chlorophyll/pigments)
Photosynthesis in the thylakoids
Fix CO2 in carboxysomes
Float with gas vesicles
Fix N2 in heterocysts
What are the phylum of Gram +?
Firmicutes (low GC) and Actinobacteria (high GC)
Contain thick cell walls, reinforced by teichoic acids.
What are the spore-forming firmicutes?
, Bacillus and Clostridium
What are some examples of bacillus?
B. anthrax (anthrax)
B. thuringiensis (organic insect repellant that makes Cry toxins)
B. subtilis ("model organism")
Why would a vegetative cell create endospores?
Unfavorable conditions cause the creation of spores
What are some examples of clostridium?
C. botulinum
C. tetani
C. difficile
Endospores swell, form drumstick appearance.
What are the non-spore-forming firmicutes?
(not all bacillales and clostridiales)
Lactic acid bacteria (aerotolerant)
-Lactococcus
-Lactobacillus
-Leuconostoc
What are the pathogenic firmicutes?
