At present there are four phyla in the domain Bacteria.
Transposons can be found on many genetic elements, including plasmids,
chromosomes, and viral genomes.
Both hydrophilic and charged molecules readily diffuse through the cytoplasmic
membrane.
The atmosphere of primitive Earth is usually classified as an oxidizing atmosphere.
Penicillin selection is a positive selection for the isolation of mutants with growth factor
requirements.
Chemoheterotrophic bacteria are primary producers.
With few exceptions, hyperthermophilic crenarchaeotes are obligate aerobes.
The Calvin cycle provides autotrophs the ability to convert inorganic carbon into
biomass and generate energy during this process.
In the United States and other developed countries, deaths due to infectious diseases are
decreasing.
MOST of the early cases of toxic shock syndrome in women were associated with use
of highly absorbent tampons.
Two-thirds of terrestrial environments support growth of termites.
Differentiation occurs only in multicellular organisms.
A two-component regulatory system usually involves both the sensor and response
proteins being subject to phosphorylation.
Thermoplasma contains an extremely small genome complexed with a highly basic
DNA-binding protein.
After a B cell is activated, it no longer needs T cell interactions or cytokines to make
antibody.
In taxonomy, family is a more general term than order.
Chlamydiae are MOST commonly transmitted throughout environments by insects.
One reason food is refrigerated to control microbial growth is because irreversible cell
damage is more likely to occur at low rather than high temperatures.
The upper respiratory tract usually has a considerable amount of resident microflora in
a healthy adult.
If a substance is reduced, it gains electrons.
Generation of new bacillus-shaped cells starts with one cell elongating and terminates
when split into two separate bacilli.
Archaeal histones assist in maintaining the DNA in a double-stranded form at very high
temperatures in species of Euryarchaeota.
Mineral soils largely come from weathered limestone and sand.
Malassezia spp. are the MOST common fungi present on the skin of humans.
Virulence refers to the ability of an organism to cause disease.
Due to their indispensible role for copying its genome, an intracellular host protease
that attacks the adenoviral protein ends would likely result in halting its replication.
Most plasmids are circular rather than linear.
A bacterial isolate that grows better on a nutrient agar plate supplemented with amino
acids but still grows in a nutrient agar plate lacking amino acids suggests amino acids
are trace nutrients for the isolate.
Iron-reducing bacteria are obligately aerobic organisms that reduce ferric iron and
oxidize hydrogen or organic compounds.
Some crenarchaeotes have growth optima above the boiling point of water (at
atmospheric pressure).
Normal microflora are usually found in the blood, lymph, and nervous systems of the
body.
The environment in which a microbial population lives is its habitat.
Mannose on mammalian cells is inaccessible to mannose-binding lectin.
Biofilms in the human mouth primarily contain pathogens.
Clostridium botulinum cannot produce toxins in improperly preserved foods.
Dead phagocytes make up much of the material of pus.
The energy source derived from the charge separation across the cytoplasmic membrane
is referred to as
A) the proton motive force.
B) carbohydrate charging.
C) adenosine triphosphate.
D) the voltage source.
Staining methods are suitable for obtaining ________ information about the number of
cells in natural samples.
A) qualitative
B) quantitative
C) both qualitative and quantitative
D) neither qualitative nor quantitative
Which of the following is considered an opportunistic pathogen?
A) Toxoplasma gondii
B) Trichomoniasis vaginalis
C) Candida albicans
D) Plasmodium vivax
Microsporidia were previously thought to be an early-branching taxon of Eukarya due
to their parasitic lifestyle. However, new evidence suggests they have evolved into a
parasitic lifestyle through adaptive gene loss which places them as close relatives of the
zygospore-producing
A) ascomycetes.
B) chytridiomycetes.
C) glomeromycetes.
D) zygomycetes.
Which scientific objective is LEAST related to microbial genetics?
A) determining the ancestral origin of a recently discovered bacterium
B) identifying mutations in a bacterial population
C) identifying quorum sensing interactions among bacteria
D) manipulating a microorganism for bioremediation
Antibody-mediated immunity is particularly effective against
A) extracellular pathogens.
B) intracellular pathogens.
C) both extra- and intracellular pathogens.
D) None of the answers are correct.
Most nitrogen-fixing bacteria symbiotically associated with plants are called
A) bacteroids.
B) mycorrhizae.
C) rhizobia.
D) symbiodinia.
Bacterial oxidation of Fe2+ occurs BEST under which environmental condition?
A) cold temperature
B) high sunlight
C) low (acidic) pH
D) nutrient-replete
The largest reservoir of methane is found
A) trapped under permafrost and marine sediments.
B) in the rumen of cows and other ruminant animals.
C) in the atmosphere.
D) trapped in volcanic rocks.
What is the difference between a methylotroph and methanotroph?
A) Methylotrophs are strict anaerobes, while methanotrophs are strict aerobes.
B) Methylotrophs use organic carbon lacking C-C bonds as electron donors and carbon
sources, while methanotrophs exclusively use methane as an electron donor and carbon
source.
C) Methylotrophs produce organic carbon lacking C-C bonds, while methanotrophs
exclusively produce methane.
D) Methylotrophs are in Proteobacteria, while methanotrophs are in Archaea.
Proteins known as ________ function to refold partially denatured proteins.
A) histones
B) chaperonins
C) HU proteins
D) histones and chaperonins
Which element functions BOTH as an enzyme cofactor and as a stabilizer of ribosomes
and nucleic acids?
A) iron
B) hydrogen
C) zinc
D) magnesium
The cells active in both innate and adaptive immunity develop from common
pluripotent precursors in the bone marrow called
A) B cells.
B) killer cells.
C) stem cells.
D) leukocytes.
What would be the consequence of deleting the late T4 genes?
A) The T4 genome would not be copied.
B) T4 mRNA would not be produced.
C) T4 capsid proteins would not be made.
D) ATP would not be produced and the T4 genome would not be packaged into the
capsid.
Herpesviruses can cause all of the following diseases in humans EXCEPT
A) cancer.
B) chicken pox.
C) cold sores.
D) spongiform encephalopathy.
Which process listed below does NOT require homologous recombination to maintain
the new genetic material in the recipient cell?
A) conjugation of an F+ plasmid
B) gene transfer through a genetic transfer agent
C) transduction by a dsDNA phage Mu
D) transformation of a linear piece of DNA
DNA replication involves the synthesis of an RNA primer on one strand of the DNA.
Antibodies consist of four polypeptides, ________ heavy chains, and ________ light
chains.
A) one / three
B) two / two
C) three / one
D) four / four
Cell density in a chemostat is controlled by
A) the concentration of the limiting nutrient.
B) the dilution factor.
C) the size of the initial inoculum.
D) the concentration of the limiting nutrient, the dilution factor, and the size of the
initial inoculum.
Which of the following is/are considered (a) direct contact infection(s)?
A) syphilis
B) gonorrhea
C) skin infections
D) syphilis, gonorrhea, and skin infections
Describe the differences between the algae and the cyanobacteria.
In ________ several ribosomes can simultaneously translate a single mRNA molecule
in a complex called a(n) ________.
A) prokaryotes / polysome
B) eukaryotes / polysome
C) prokaryotes / initiation complex
D) eukaryotes / splicing complex
Interpret the results to the following experiment. Transcriptional activity of chemotactic
genes showed a high expression level during the following conditions: repelling away
from compound 1, moving towards compound 2, and remaining sessile when presented
compounds 3 and 4.
A) Activity during movement in any direction led to high measurements observed, and
the sessile population responded equally to both a chemoattractant and a
chemorepellant but remained in the same location for their net movement.
B) Gene expression by itself cannot distinguish between cells responding to both an
attractant and repellent, so this ambiguity makes transcriptomics unfavorable but
nonetheless indicates activity.
C) The activity observed during a sessile existence suggests the molecular probe was
targeting a chemotactic gene that is also involved in other non-chemotactic functions
due to the activity observed.
D) Transcriptomics as a whole cannot be used for chemotaxis genes because they are
not regulated at the transcriptional level (i.e., they are constitutive), which is why
activity is observed on all three conditions.
What are the primary chemical mediators released from mast cells during a type I
hypersensitivity reaction?
A) antibodies
B) interleukin I and tumor necrosis factor
C) histamine and serotonin
D) cytokines
In class switching in the secondary antibody response, the most common antibody
switch is from
A) IgA to IgD.
B) IgD to IgE.
C) IgM to IgG.
D) None of the answers are correct.
When a virus enters a host cell in which it can replicate, the process is called a(n)
A) insertion.
B) infection.
C) prophage.
D) excision.
How are root nodule and arbuscular mycorrhizal symbioses similar?
A) They both use lipochitin oligosaccharide signaling factors to initiate root
colonization.
B) They both supply nitrogen to the host plant through nitrogen fixation.
C) They both increase absorption of nutrients from soil.
D) They are both required for the growth and reproduction of their host plants.
A common method used in the diagnosis of giardiasis is detection of Giardia
A) cysts in stool.
B) antigens in blood.
C) antigens in stool.
D) cysts or antigens in stool.
Effluent water is wastewater
A) discharged from the pharmaceutical, plastics, and petrochemical industries.
B) discharged from the wastewater treatment facility.
C) that has undergone anoxic secondary wastewater treatment.
D) that is imported to the wastewater treatment facility for treatment.
Protein A has a strong affinity for
A) antigen.
B) blood.
C) protein.
D) antibody.
Many aromatic compounds used for growth substrates by bacteria are broken down
during high heat autoclaving. Which is the BEST way to sterilize these aqueous
solutions?
A) ethylene oxide gas treatment
B) gamma irradiation
C) 0.2 μm filter sterilization
D) ultraviolet radiation
A microbe growing in a refrigerator is likely
A) psychrophilic.
B) mesophilic.
C) psychrotolerant or psychrophilic.
D) hyperthermophilic.
The genes encoding luciferase, green fluorescent protein (GFP), and β-galactosidase are
typically used in cloning as
A) transcription regulators.
B) global control genes.
C) promoter sequences.
D) reporter genes.
An example of pathogen-associated molecular patterns (PAMP) is
A) cell-surface proteins.
B) flagellin proteins.
C) lipopolysaccharide (LPS).
D) pilus.
Oxygen did not accumulate in the early atmosphere until it reacted with reduced
materials, especially ________, in the oceans.
A) hydrogen
B) elemental sulfur
C) ferrous iron
D) nitrate
What makes Listeria monocytogenes an especially difficult-to-prevent foodborne
pathogen? Once in the human body, how does it evade the immune system?
How does plating efficiency affect the number of plaque-forming units? How is plating
efficiency calculated?
What is the difference between an operator and a promoter?
Describe beneficial and harmful ways in which microorganisms interact with
agricultural crops.
Under what circumstances does oxygenic photophosphorylation use non-cyclic
photophosphorylation and when does it use cyclic photophosphorylation? Also describe
what occurs during each process.
Speculate why the half-life of mRNA is short, while the half-lives of rRNA and tRNA
are long.
In the context of the influenza virus, describe the mechanistic difference between an
antigenic drift and an antigenic shift. Also indicate the result of each.
Tilling or plowing is a common agriculture practice that has been proven to have a
profound impact on the nitrogen cycle. Tilling breaks up hard soils to ease the planting
and germination of crops, and it also introduces more oxygen into the soil. Many
fertilizers contain N in the form of ammonia because ammonia is readily absorbed and
used by plants, while N in the form of nitrate is more mobile and is more easily lost
from the soil. Based on your knowledge of microbial transformations of inorganic
nitrogen species, what impact would you predict extensive tilling to have on the fate of
ammonium-based nitrogen fertilizer?
Explain why the proteome is NOT defined as “all the proteins encoded by an organism’s
genome.”
Briefly describe the effect of deposition of antibody or complement on the surface of a
pathogen or antigen in relation to opsonization.
Speculate on the possibility of life on other planets. Use representatives of the
hyperthermophilic Archaea and hydrogen chemolithotrophs as a guide to this
discussion.
Explain why a hyperthermophile is unlikely to be a human pathogen.
Explain the terms “core genome” and “pan genome” and describe how each contributes
to the genome of a bacterial species. Give an example of genes that are part of a core
genome versus those that are more often in the pan genome.
What is tolerance, and why must the adaptive immune system exhibit tolerance?
Given that T cell receptors (TCRs) are randomly generated during the maturation
process, how are new T cells selected that can recognize self-antigens and other
immune cells appropriately?
Fifteen high school students visited a local farm in central Wisconsin for a weekend
where they enjoyed petting farm animals, riding horses, and campfire meals. With
sanitation in mind, only one individual remembered to wash her hands with water
pumped from a well after petting the animals before dinner. After two weeks of the girl
passing out at random occasions, she was rushed into the emergency room where
doctors determined she was severely dehydrated. Explain how it took direct observation
of a fecal sample to solve this potential life-threatening disease and how this disease
was treated in the otherwise healthy girl. Also mention any necessary precautions the
individual should have taken after being diagnosed with the disease.
How does the genus Pfiesteria cause problems in both humans and fish?
Describe the usefulness of blue-white screening, also called α-complementation, in
cloning vectors such as pUC19. Include in your answer the terms polylinker, DNA
ligase, lacZ gene, insertional inactivation, Xgal, and β-galactosidase.