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The bacterium Escherichia coli comprises a significant fraction of the bacterial
population in healthy adult humans, ranging from 10-50%.
The lag phase does NOT occur if all the cells in the culture are viable.
Functional differences can be observed by using 16S rRNA gene phylogenetics of a
microbial community.
Fermentation of organic compounds, such as acetate, produces NADH and ATP.
Sequencing technology and molecular phylogenetic analyses have had very little impact
on our understanding of the evolution and diversity of life on Earth.
At this time, EIA tests are too difficult for routine diagnoses.
In the EIA test for HIV infection, the microtiter plate is coated with disrupted HIV
particles.
Secondary treatment may be aerobic or anoxic.
A common structure for proteins that bind DNA is helix-turn-helix.
Animals that lack CXCR4 and CCR5 proteins are immune to HIV infection.
The terminating step of moving electrons onto oxygen releases additional ATP during
aerobic metabolism not made during anaerobic growth.
Antibiotic therapy is not significantly useful for treating typhoid fever.
Most microorganisms are pathogenic.
Nonencapsulated strains of Streptococcus pneumoniae are highly virulent.
When using the EIA test for HIV screening, BOTH false negative and false positive
results are possible.
Organisms in natural environments can be detected by assaying for the presence of their
genes.
Most of the Archaea are phenotypically quite similar.
Slime molds feed by phagocytosis and are more closely related to amoebas than to
fungi.
Most bacterial phyla lack strong phenotypic cohesiveness.
Plasmodium vivax causes a more serious form of malaria than does P. falciparum.
In adaptive immunity, pathogen specific receptors are produced in large numbers only
after exposure to the pathogen or its products.
Viruses have both an intracellular and an extracellular form.
Though the known diversity of acetotrophic methanogens is low, they are ecologically
significant in nature.
All Hfr strains possess an F factor integrated into the host chromosome.
ALL positive HIV-EIA tests must be confirmed by another independent test, usually the
HIV Western blot.
Proteins and RNA molecules that are needed in the cell, at about the same level under
all growth conditions, require constitutive expression.
Proteins required at approximately the same level throughout a cell's growth cycle are
often not subject to regulatory mechanisms and are constitutively synthesized.
Although various codons often code for the same amino acid, it is important to choose
the codon preferred by the expression host itself.
In clonal selection, cells that have not interacted with antigen do not proliferate.
Small molecules usually act directly (rather than indirectly) in regulating transcription.
Which of the following is/are used to identify methicillin-resistant Staphylococcus
aureus?
A) selective media
B) differential media
C) PCR
D) selective media, differential media, and PCR
Chloroplasts and mitochondria originated from ________ by a process known as
________.
A) bacteria / chromosome reduction
B) plants / gene deletion
C) bacteria / endosymbiosis
D) plants / endosymbiosis
Some members of the Thermoplasmatales can grow at pH levels below
A) 4.
B) 7.
C) 0.
D) 10.
Which metabolic cycle or pathway is LEAST likely to be invoked during the
biosynthesis of DNA?
A) citric acid cycle
B) glycolysis
C) gluconeogenesis
D) pentose phosphate pathway
Viral replication is
A) independent of the host cell's DNA but dependent on the host cell's enzymes and
metabolism.
B) independent of both the host cell's DNA and the host cell's enzymes and metabolism.
C) dependent on the host cell's DNA and RNA.
D) dependent on the host cell's DNA, RNA, enzymes, and metabolism.
Erythromycin is put in the eyes of newborns specifically to prevent
A) syphilis.
B) gonorrhea.
C) a chlamydial infection.
D) ocular herpes.
Using a host defective in proteases is likely to be necessary when engineering
A) a complete metabolic pathway requiring several different enzymes.
B) overproducing proteins.
C) production of a small protein.
D) transgenic animals with immune systems.
Nongonococcal urethritis may be caused by the protozoan ________.
A) Chlamydia trachomatis
B) Neisseria gonorrhoaea
C) Haemophilus ducreyi
D) Trichomonas vaginalis
DiGeorge's syndrome is a developmental defect that prevents the maturation of the
thymus. What cell type would be reduced by this condition?
A) T cells
B) B cells
C) macrophages
D) lymphocytes
What phenomenon accounts for the appearance of chloroplasts in some unicellular
phototrophic eukaryotes?
A) endosymbiosis
B) secondary endosymbiosis
C) sequencing of chloroplasts' SSU genes
D) horizontal gene transfer
Early and late viral proteins are classified according to their relative
A) evolutionary appearance in virus genomes.
B) stability during infection.
C) time of synthesis following host infection.
D) transmission into virions.
Microbes are sometimes used in secondary treatment of wastewater to
A) convert heavy metals into carbon dioxide.
B) remove organic matter.
C) remove large particles.
D) convert heavy metals into carbon dioxide, remove organic matter, and remove large
particles.
Thirty organisms containing the same phylogenetic marker are all considered to be
within the same
A) phylotype.
B) species.
C) functional group.
D) phylogenetic tree.
Eukaryotes have ________ in their cytoplasmic membranes, which serve to strengthen
and stabilize the membrane and make it less flexible. Many bacteria have similar
molecules, known as ________, in their cytoplasmic membranes that have a similar
role.
A) ether bonds / ester bonds
B) lipids / phospholipids
C) sterols / hopanoids
D) phospholipids / lipopolysaccharides
________ are the main primary producers in freshwater environments.
A) Phototrophic microorganisms
B) Heterotrophic microorganisms
C) Chemolithotrophic microorganisms
D) Viral microorganisms
Only particles smaller than ________ m in diameter reach the lungs.
A) 10
B) 20
C) 30
D) 40
What role does Acidithiobacillus ferrooxidans play in the copper leaching process?
A) oxidation of sulfide to sulfate
B) reduction of oxidized iron (Fe3+) to reduced iron (Fe2+)
C) oxidation of reduced iron (Fe2+) to oxidized iron (Fe3+)
D) reduction of sulfate to sulfide
The ________ is a highly conserved amino acid sequence found in immunoglobulin,
TCR, and MHC proteins.
A) heavy chain
B) V domain
C) C domain
D) light chain
Some nitrifying prokaryotes carry out metabolic cooperation by a process known as
A) competition.
B) niche partitioning.
C) syntrophy.
D) antagonism.
The purposeful artificial stimulation of active immunity to a particular infectious
disease is known as
A) immunodeficiency.
B) hypersensitivity.
C) immunization.
D) opsonization.
Regulatory proteins
A) are influenced by small molecules.
B) bind to specific DNA sites.
C) regulate transcription.
D) regulate transcription, bind specific DNA sites, and can be influenced by small
molecules.
The production of ________ by ________ is thought to be a major contributor to the
biodeterioration of stone building materials.
A) oxalic acid / fungi
B) sulfuric acid / sulfate reducers
C) nitric acid / nitrate reducers
D) carbonic acid / lichens
Biomass generation due to heterotrophic organisms is called ________ production.
A) primary
B) secondary
C) auxotrophic
D) regulatory
The use of selected culture media and incubation conditions to isolate microorganisms
from samples is known as a(n)
A) differential culture.
B) selective culture.
C) enrichment culture.
D) sensitive culture.
New vaccine strategies resulting from progress in biochemistry and molecular biology
include the production of
A) DNA vaccines.
B) recombinant vector vaccines.
C) synthetic peptide vaccines.
D) DNA, recombinant vector, and synthetic peptide vaccines.
Bacillus anthracis deficient in its ability to differentiate would not be able to
A) chemotax towards growth substrates.
B) create vessicles.
C) form endospores.
D) grow without additional supplemented nutrients.
Which characteristic is NOT associated with Vibrio spp.?
A) aquatic
B) gliding motility
C) gram-negative
D) pathogenic
Which of the following factors has delayed the development of laboratory-based
genetic systems in Archaea?
A) There are no documented systems of conjugation in Archaea.
B) Homologous recombination does NOT occur in Archaea.
C) Archaeado NOT host viruses or plasmids.
D) Many archaea grow in extreme or unusual conditions that make the use of agar and
traditional mutant screening techniques problematic.
How would you label and separate the DNA of unknown methylotrophs in a sample?
A) Incubate the sample with 13C-methane.
B) Hybridize the DNA to FISH probes.
C) Use DGGE to separate the strands of DNA in the sample.
D) Use T-RFLP to identify the methylotroph DNA in the sample.
Symbionts such as Aeromonas veronii of leeches and Buchnera symbionts of insects are
transmitted ________ to ensure the safe transfer of the symbiont to the next host
generation.
A) vertically to offspring
B) horizontally through infected water
C) horizontally through infected secondary hosts
D) vertically through the air
Two main symbionts of termites are ________ and ________.
A) archaea / bacteria
B) bacteria / fungi
C) bacteria / protists
D) fungi / protists
Select a group within Bacteria that has a rare structural morphology observable with a
microscope. Describe the appearance, the group that it corresponds to, and another
group that would certainly be ruled out when observing such a morphology.
Explain the tuberculin test, including visual identification and immunological
interpretation of positive and negative results, and describe why a positive test does not
indicate an active infection.
Design five amino acid peptides that could be bound by a single hypothetical class I
MHC protein. The MHC proteins binds peptides that are 10 amino acids long and have
two anchor residues, tyrosine and isoleucine, at positions 2 and 5.
Provide evidence supporting the statement that an ecosystem is controlled by microbial
activities.
Explain the nature and function of an enrichment culture.
Major histocompatibility complex (MHC) proteins, antibodies, and T cell receptors are
all highly variable so that they can interact with a large number of different antigens.
How is variability generated for each of these important antigen-binding proteins?
Explain the Calvin cycle process that produces a full molecule of glucose and
regenerates the ribulose bisphosphate molecule.
Genome sequencing of the bacterial symbionts of animals has allowed us to compare
the genomic features of several symbionts. The following data were collected on two
insect symbionts:
Symbiont A: 0.4 Mb genome, 20% G+C content, missing or incomplete peptidoglycan
synthesis and nucleotide synthesis pathways.
Symbiont B: 1.8 Mb genome, 40% G+C content, peptidoglycan and most nucleotide
synthesis pathways complete.
What can you deduce about these two insect symbionts based on their genomes?
Why is the biological species concept useful for Eukarya but not meaningful for
Archaea and Bacteria? How are prokaryotic species defined?
In what types of organisms are carboxysomes found and what advantage do they
provide for a cell?
Describe the establishment and maintenance of the lysogenic state in the lambda phage.
Explain why most iron-oxidizing bacteria are obligately acidophilic, and discuss some
of the environments where these organisms are found.
Microbes were first formally observed during the mid-1600s, but the cell theory was
not enunciated until 1839. Write a brief essay explaining why microbiology did not
become a formally recognized science until Louis Pasteur's and Robert Koch's time.
Predict what would happen to a motile bacterium undergoing chemotaxis if the Mot
proteins suddenly ceased to function.
Provide evidence that supports the hypothesis that riboswitches are remnants of the
RNA world when catalytic RNAs were the only self-replicating life forms.
Interpret the genomic content of mitochondria in relation to their evolution. How is
mitochondrial evolution more complicated than expected?
Explain the biosynthetic and bioenergetic roles of the citric acid cycle.
Why do individuals with genetic defects that prevent neutrophil or macrophage
development usually die at an early age? Be specific and detailed in your answer to
demonstrate your knowledge on the role of these cells in the immune system.
How is the leucine zipper formed, and what is its function?
