MGG Exam 4 questions well answered
graded A+ 2025/2026
What percentage of the human gut microbiota is Bacteria, as opposed to Archaea or fungi? -
correct answer ✔✔98%
Primers used to amplify segments of 16srRNA for metagenomic analysis bind to sequence -
correct answer ✔✔Flanking a variable region
Which of the following bacterial phyla are Gram (+) - correct answer ✔✔Firmicutes
What characterizes Gram (-) bacteria? - correct answer ✔✔Double membranes; less
peptidoglycan than Gram (+)
Salmonella, Shigella, and Escherichia belong to which class of Proteobacteria? - correct answer
✔✔Gamma
Which of the following pathogens is in the phylum Actinobacteria? - correct answer
✔✔Mycobacterium tuberculosis
Which of the following is in the phylum Firmicutes - correct answer ✔✔Staphylococcus
What percentage of the human microbiota is in the colon, as opposed to the stomach, nose,
throat, skin, etc? - correct answer ✔✔90%
What two types of data do you use form the GreenGenes database in metagenomics? - correct
answer ✔✔A pre-made phylogenetic tree and the sequence found at each leaf
, Why do we use the MAFFT alignment program in Taxonomic Classification in QIIME? - correct
answer ✔✔To assign our 16S rRNA sequence to the 16S rRNA sequences from the GreenGenes
In Taxonomic Classification in QIIME, what are the three feature tables of data we use? - correct
answer ✔✔A "Tree of Life" (GreenGenes), 16S rRNA sequences (GreenGenes), 16S rRNA
sequence (our data)
What spurious sequences does the Taxonomic Classification help you eliminate form your
metagenomics dataset? - correct answer ✔✔Non bacterial sequences
What gaps are formed in the aligning of two sequences, the computer assigns two types of
penalties for these gaps - what are they? - correct answer ✔✔Gap formation versus extension
In a distance matrix, why are the values down the diagonal always 0.0 by definition? - correct
answer ✔✔Your re comparing each sequence with itself
What do you do with sequences that dont match exactly to a sequence in the reference table? -
correct answer ✔✔Use a fragment insertion program to shoerun the sequence into the
standard tree
Beta diversity among two samples is measured as: - correct answer ✔✔The sum of (that
sample's species - shared species) for each sample
Faith's Alpha Diversity Index uncles everything that Shannon's index includes plus what extra
component - correct answer ✔✔The evenness of the species distribution across the
phylogenetic tree
What question does a rarefaction curve answer? - correct answer ✔✔Have I captured the bulk
of the diversity of my sample x number of reads?
graded A+ 2025/2026
What percentage of the human gut microbiota is Bacteria, as opposed to Archaea or fungi? -
correct answer ✔✔98%
Primers used to amplify segments of 16srRNA for metagenomic analysis bind to sequence -
correct answer ✔✔Flanking a variable region
Which of the following bacterial phyla are Gram (+) - correct answer ✔✔Firmicutes
What characterizes Gram (-) bacteria? - correct answer ✔✔Double membranes; less
peptidoglycan than Gram (+)
Salmonella, Shigella, and Escherichia belong to which class of Proteobacteria? - correct answer
✔✔Gamma
Which of the following pathogens is in the phylum Actinobacteria? - correct answer
✔✔Mycobacterium tuberculosis
Which of the following is in the phylum Firmicutes - correct answer ✔✔Staphylococcus
What percentage of the human microbiota is in the colon, as opposed to the stomach, nose,
throat, skin, etc? - correct answer ✔✔90%
What two types of data do you use form the GreenGenes database in metagenomics? - correct
answer ✔✔A pre-made phylogenetic tree and the sequence found at each leaf
, Why do we use the MAFFT alignment program in Taxonomic Classification in QIIME? - correct
answer ✔✔To assign our 16S rRNA sequence to the 16S rRNA sequences from the GreenGenes
In Taxonomic Classification in QIIME, what are the three feature tables of data we use? - correct
answer ✔✔A "Tree of Life" (GreenGenes), 16S rRNA sequences (GreenGenes), 16S rRNA
sequence (our data)
What spurious sequences does the Taxonomic Classification help you eliminate form your
metagenomics dataset? - correct answer ✔✔Non bacterial sequences
What gaps are formed in the aligning of two sequences, the computer assigns two types of
penalties for these gaps - what are they? - correct answer ✔✔Gap formation versus extension
In a distance matrix, why are the values down the diagonal always 0.0 by definition? - correct
answer ✔✔Your re comparing each sequence with itself
What do you do with sequences that dont match exactly to a sequence in the reference table? -
correct answer ✔✔Use a fragment insertion program to shoerun the sequence into the
standard tree
Beta diversity among two samples is measured as: - correct answer ✔✔The sum of (that
sample's species - shared species) for each sample
Faith's Alpha Diversity Index uncles everything that Shannon's index includes plus what extra
component - correct answer ✔✔The evenness of the species distribution across the
phylogenetic tree
What question does a rarefaction curve answer? - correct answer ✔✔Have I captured the bulk
of the diversity of my sample x number of reads?
