Exam 3 18 Flashcards
Which of the following is the first of Koch’s postulates?
not c
B: determine if the microbe is present in well versus sick individuals
What sort of microbes do bacteriologists study?
a: archaea
What term best describes the shape and arrangement of the cells to the right? (clusters of ball-shaped cells)
C: staphylococci
Which of the following membranes is most likely to be found in a cyanobacterium?
B: thylakoid
Which of these microbes would most likely contain peptidoglycan in their cell wall?
not A (euryarcheoata)
From which group of bacteria are thought to have formed mitochondria through endosymbiosis?
proteobacteria
Which of these microbes are most likely to form endospores in response to starvation?
Clostridium and Bacillus
What cellular structure is most responsible for protein trafficking in eukaryotic microbes?
Golgi body
To which group of fungi does Saccharomyces cereuisiae (bakers yeast) belong?
Ascomycetes
What structures do members of the Amoebozoa use for cellular motility?
Pseudopodia
Zika virus has a ssRNA (+) genome. To which Baltimore class does it belong?
Class IV
Which of these was true of the results of the experiments performed by Hershey and Chase?
32P pelleted with the cells, 35S remained in the supernatant
Assume that you have a microbial culture with a growth rate (k) of 3 hr-i. If you start with 2,00o cells
at time zero, how many would you have after one hour of growth under optimal conditions?
16000
Examine the dilution to the right. How many cfu/ml were in the original flask if 15 colonies were
observed on the plate?
(transfer 1ml four times into 9ml, plate 0.1ml from final tube)
1.5 x 10^6
How many total ATP are formed during glycolysis from one
glucose?
4
What type of growth is illustrated by the microbe in the thioglycollate tube to the right?
Obligate anaerobe
What process results in the net production of ATP during the Entner Doudoroff reaction?
Substrate level phosphorylation
Which of the following processes is involved in forming ethanol during metabolism?
Fermentation
What type of chemical reaction is illustrated to the right? (reactants have a higher energy than products)
Exergonic
Identify activation on a graph of the free energy of a reaction
the bump
Which of these describes the nature of the proton motive force illustrated to the right?
delta psi only
What term refers to the pollution of ground water through the introduction of excess phosphorus?
Eutrophication
What process is indicated by this reaction? NH4 ~ NO3
Nitrification
You have determined that the genome of Clostridium sporogenes is 16% G. What percentage of its
genome should consist of A?
34%
What happens at oriC in Escherichia coli?
DNA replication is initiated
How do fungi condense their DNA to fit it within the confines of their cells?
Histones
Which is true of chromosomal replication in bacterial cells
It progresses from 5’ to 3’
. What term refers to the short RNA sequences that are formed to initiate DNA extension reactions
during replication?
Primers
What enzyme is responsible for filling in the short gaps following RNase H activity during replication?
DNA polymerise I
What components make up a nucleotide from a bacterial genome?
Nitrogenous base, deoxyribose, and phosphate
What is connected to the 3’ carbon of the five-carbon sugar in DNA?
A hydroxyl group
While performing a variation on the work of Messelson and Stahl, you grew Escherichia coli
overnight in media with all ~4N nitrogen. After pelleting the cells by centrifugation and rinsing, you
then allow them to grow for exactly two generation times in media containing only .Which of these
patterns will you observe if you sediment DNA extracted from these cells in an ultr~entrifuge.
two lines, one in the middle and one at the bottom
Which of these sequences puts the steps of eukaryotic gene expression into the correct order?
Transcription ~ Splicing ~ Move through nuclear pore ~ Translation
Which protein is responsible for recognizing the promoter during prokaryotic gene expression?
Sigma
What is the function of Rho during gene expression?
Transcriptional termination
What term illustrates the collection of genes shown to the
right?
Operon
What is removed from a maturing mRNA during the process of splicing?
Introns
Which of these proteins is involved in protein export in Escherichia coli
SecA
What does 16S rRNA recognize during translation?
Shine Dalgarno sequence
Which of the following would be complementary mRNA produced from this DNA sequence?
3’ TACTATGAATCC 5’
5’ AUGAUACUUAAG 3’
What peptide is encoded by the mRNA in question 4i? (Table is provided)
MILK
What type of gene regulation does CRP exhibit?
NOT Negative inducible regulation
NEED CORRECT ANSWER
Which of the following is the most likely genotype for the strain shown to the right (+ =yellow)?
LacI-
What is the best explanation for the phenotype seen in question 44?
The mutated regulatory protein cannot bind to the DNA
What type of gene regulation does wild type (normal) LacZYA exhibit?
NOT Negative repressible regulation
NEED CORRECT ANSWER
Which of the following secondary structures represents the tryptophan attenuator?
NOT Region 2 paired to region 3
NEED CORRECT ANSWER
What is the function of the LacZ protein?
Cleave lactose
Which of the following proteins favors the lytic cycle in bacteriophage lambda?
Cro
Which of these conditions favors the lysogenic cycle in bacteriophage lambda?
High multiplicity of infection
What is the result of high CheA~P (phosphorylated) levels in Escherichia coli chemotaxis?
more frequent tumbling
What effect does increasing methylation of acceptor proteins have on chemotaxis in Escherichia coli?
NOT The cells tumble more often
NEED CORRECT ANSWER
Which of these processes involves the participation of autoinducers?
Quorum sensing
Which of the following would lead to the activation of glutamine synthase enzyme activity?
AMP is removed from G1nA
TrpR by itself is
Called the aporepressor
Where would you find enhancers and silencers in a cell?
Nucleus
What enzyme catalyzes this reaction? RNA -~ DNA
Reverse transcriptase
Which of these processes involves an invertible DNA fragment containing a promoter sequence?
Phase variation
Which of these statements is true for Escherichia coli grown under high glucose conditions?
G1cIIA protein is not phosphorylated
Assume that you are trying to do a gel mobility shift experiment using DNA from normal strain.
Lane i has just a DNA fragment containing the tryptophan promoter and operator sequences.
Lane 2 has the same fragment along with normal (functional) TrpR protein.
Lane 3 has the same fragment, normal TrpR protein, and tryptophan.
Which electrophoreticpaffern is correct for this experiment?
1 2 3
_
_ _
What is typically measured with two-dimensional gel electrophoresis ?
Translational activity under different conditions
The transcription of iron transport genes is regulated by a protein called Fur. Fur binds to an operator
in the presence of iron and turns off transcription. What sort of regulation is this?
NOT Positive~repressible regulation
NEED CORRECT ANSWER
What term refers to cells that can take up naked DNA from their environment?
Competent
Because it can integrate into the host cell’s chromosome, the F factor is referred to as
An R factor
Which of the following processes involves the action of a defective lysogenic bacteriophage?
Specialized transduction
What type of mutation is this (refer to question~42 for assistance, the table)? ACC ~ AAC
Missense mutation
Which of these is a transition mutation?
G to A
What type of genetic mutation is caused by 5-bromouracil treatment?
Transition
Insertion sequences (like ISio) contain the gene for the enzyme
Transposase
What type of mobile genetic element is shown to the right?
lnpA res tnpR bla
tn8
NOT COMPLEX TRANSPOSON
NEED CORRECT ANSWER
What component of a retrovirus is missing from an LTR element?
env gene_
Which Baltimore class of viruses is most dependent upon the host cell’s enzyme for replication
Class I
Which Baltimore class of viruses uses reverse transcriptase while in the host cell?
Class VI
What is the first protein produced by the poliovirus during infections?
RNA polymerase
Which of these processes is most likely to form aseven-carbon intermediate?
Pentose phosphate shunt
What type of mobile genetic elements include the Alu sequences in our genomes? .
SINE
