TTU MBIO 3401 Exam 3 (Keyel)
Questions & Answers (Grade A+)
Metagenome -
correct answer ✅the sum total of ALL DNA sequenced from an
environmental sample
*can be any natural or human made environment or the
microbiome of a plant or animal
a. the small subunit rRNA sequence is the standard for identifying
environmental taxa
Microbiome -
correct answer ✅the microorganisms in a particular environment
*host-associated microbes
Small Subunit (SSU) rRNA -
correct answer ✅SSU rRNA gene similarity is used to define
operational taxonomic units
*the standard method for identifying species is to compare the SSU
rRNAS genes
a. 16 SSU rRNA for prokaryotes
b. 18 SSU rRNA for eukaryotes
c. species diversity of a metagenome can be estimated by a
rarefaction curve
d. 16s rDNA gene codes for making SSU rRNA
,TTU MBIO 3401 Exam 3 (Keyel)
Questions & Answers (Grade A+)
e. Sanger Approach
Operation taxonomic units (OTUs) -
correct answer ✅a working metagenomic definition of species
*use SSU rRNA gene similarity to define
Rarefaction curve -
correct answer ✅plots the number of different OTUs (species)
found, as a function of increasing sample size
*how many species are observed per replication sequence
a. can estimate species diversity of a metagenome
Sanger Approach -
correct answer ✅break the gene up into smaller pieces
Deep-Branching Thermophiles -
correct answer ✅diverged the earliest from ancestral archaea and
eukaryotes
a. fastest doubling rates of all bacteria
b. high mutation rate
1. Cholorflexi
,TTU MBIO 3401 Exam 3 (Keyel)
Questions & Answers (Grade A+)
2. Phylum Deinococcus-Thermus
3. Thermotogae
4. Aquificae
Chloroflexi -
correct answer ✅*deep-branching thermophile
a. photoheterotrophic; moderately thermophilic
b. green nonsulfur bacteria
c. cholorflexus species contains photosynthetic apparatus within
chlromosomes- forms filamentous mats in association with
thermophilic cyanobacteria
Phylum Deinococcus-Thermus -
correct answer ✅*deep-branching thermophile
a. ornithine in peptidoglycan cross-bridges
b. Thermus species- moderate thermophiles and heterotrophs
c. Deinococcus radiodurans
Deinococcus radiodurans -
correct answer ✅*Phylum Deinococcus-Thermus
a. NOT thermophilic
, TTU MBIO 3401 Exam 3 (Keyel)
Questions & Answers (Grade A+)
b. resist extremely high doses of radiation and desiccation
c. thick cell-wall and S-layer
Cyanobacteria -
correct answer ✅*the only oxygenic phototrophic prokaryotes
a. contain chlorophyll and accessory pigments
b. conduct photosynthesis in thylakoids
c. Fix CO2 in carboxysomes
d. maintain buoyancy in gas vesicles
e. many fix N2 in specialized cells called heterocysts
Gram-Positive Bacteria -
correct answer ✅two distinct phylogenetic branches:
1. Phylum Firmicutes
2. Phylum Actinobacteria
a. thick cell walls reinforced by teichoic acids
Phylum Firmicutes -
correct answer ✅*gram-positive bacteria
low-GC species
Questions & Answers (Grade A+)
Metagenome -
correct answer ✅the sum total of ALL DNA sequenced from an
environmental sample
*can be any natural or human made environment or the
microbiome of a plant or animal
a. the small subunit rRNA sequence is the standard for identifying
environmental taxa
Microbiome -
correct answer ✅the microorganisms in a particular environment
*host-associated microbes
Small Subunit (SSU) rRNA -
correct answer ✅SSU rRNA gene similarity is used to define
operational taxonomic units
*the standard method for identifying species is to compare the SSU
rRNAS genes
a. 16 SSU rRNA for prokaryotes
b. 18 SSU rRNA for eukaryotes
c. species diversity of a metagenome can be estimated by a
rarefaction curve
d. 16s rDNA gene codes for making SSU rRNA
,TTU MBIO 3401 Exam 3 (Keyel)
Questions & Answers (Grade A+)
e. Sanger Approach
Operation taxonomic units (OTUs) -
correct answer ✅a working metagenomic definition of species
*use SSU rRNA gene similarity to define
Rarefaction curve -
correct answer ✅plots the number of different OTUs (species)
found, as a function of increasing sample size
*how many species are observed per replication sequence
a. can estimate species diversity of a metagenome
Sanger Approach -
correct answer ✅break the gene up into smaller pieces
Deep-Branching Thermophiles -
correct answer ✅diverged the earliest from ancestral archaea and
eukaryotes
a. fastest doubling rates of all bacteria
b. high mutation rate
1. Cholorflexi
,TTU MBIO 3401 Exam 3 (Keyel)
Questions & Answers (Grade A+)
2. Phylum Deinococcus-Thermus
3. Thermotogae
4. Aquificae
Chloroflexi -
correct answer ✅*deep-branching thermophile
a. photoheterotrophic; moderately thermophilic
b. green nonsulfur bacteria
c. cholorflexus species contains photosynthetic apparatus within
chlromosomes- forms filamentous mats in association with
thermophilic cyanobacteria
Phylum Deinococcus-Thermus -
correct answer ✅*deep-branching thermophile
a. ornithine in peptidoglycan cross-bridges
b. Thermus species- moderate thermophiles and heterotrophs
c. Deinococcus radiodurans
Deinococcus radiodurans -
correct answer ✅*Phylum Deinococcus-Thermus
a. NOT thermophilic
, TTU MBIO 3401 Exam 3 (Keyel)
Questions & Answers (Grade A+)
b. resist extremely high doses of radiation and desiccation
c. thick cell-wall and S-layer
Cyanobacteria -
correct answer ✅*the only oxygenic phototrophic prokaryotes
a. contain chlorophyll and accessory pigments
b. conduct photosynthesis in thylakoids
c. Fix CO2 in carboxysomes
d. maintain buoyancy in gas vesicles
e. many fix N2 in specialized cells called heterocysts
Gram-Positive Bacteria -
correct answer ✅two distinct phylogenetic branches:
1. Phylum Firmicutes
2. Phylum Actinobacteria
a. thick cell walls reinforced by teichoic acids
Phylum Firmicutes -
correct answer ✅*gram-positive bacteria
low-GC species
