Some of the intestinal symptoms elicited by pathogens such as Salmonella, Shigella,
and Escherichia are due to the presence of
A) pseudomurein.
B) S-layers.
C) lipopolysaccharides.
D) peptidoglycan.
Genes from different sources that are related in sequence due to shared evolutionary
ancestry are called ________ genes, and groups of such genes are known as ________.
A) homologous / gene families
B) paralogous / functional genes
C) orthologous / gene families
D) homologous / functional genes
Cytokines produced by lymphocytes are often called
A) interleukins.
B) pathogen recognition receptors.
C) chemokines.
D) epitopes.
To determine the specific growth rate of a bacterial population, it is essential to know
A) cell concentrations at varied time points.
B) total number of cells in the population at varied time points.
C) cell concentrations at varied time points or the generation time.
D) turbidity measurements and the total number of cells in the population at varied time
points.
Mycolic acids are exclusively present in Mycobacterium spp. and can be distinguished
by a(n) ________ staining procedure (which is, therefore, a diagnostic utility to identify
mycobacteria).
A) acid-fast
B) DAPI
C) Gram
D) lipo
The use of ________ is the easiest and most effective way of studying many animal and
plant viruses.
A) bacterial cultures
B) tissue or cell culture
C) live hosts
D) prophages
A bacterium containing ________ provided with hydrogen peroxide will produce
oxygen bubbles.
A) catalase
B) superoxide dismutase
C) superoxide reductase
D) peroxidase
Horizontal gene transfer in Archaea
A) is infrequent in nature and therefore difficult to use for genetic studies in the
laboratory.
B) has not been documented, thus all genetic studies of archaeaare done via genomic
sequencing.
C) frequently occurs in nature and has been used to perform genetic studies in the
laboratory as well.
D) frequently occurs in nature, but there are very few laboratory studies because
archaea do not cause human disease.
One advantage of the fluorescent antibodies that permits disease diagnosis long before
primary isolation techniques yield results is that
A) cross-reactions do not occur.
B) few controls are required.
C) nonspecific staining does not occur.
D) it may be applied directly to tissue.
Chemical reactions involving ________ have been proposed as energy-yielding
reactions for primitive organisms.
A) Fe, O2, and H2
B) S, O2, and H2
C) S, and O2
D) S, and H2
Which of the following is NOT true of Epsilonproteobacteria?
A) Abundance directly correlates with sulfur metabolism activities.
B) Pathogens require relatively low O2 levels to grow.
C) Epsilonproteobacteria are present in freshwater, marine systems, and terrestrial
environments.
D) Epsilonproteobacteria are prolific metal reducers.
Treating wastewater requires the removal of organic material, and an ideal phenotype of
a bacterium to do this would flocculate to make the cells settle (rather than staying in
suspension) in a wastewater stream. Which species would be best for this application?
A) Bartonella quintana
B) Burkholderia cepacia
C) Wolbachia pipientis
D) Zoogloea ramigera
Modified Thayer-Martin (MTM) agar
A) incorporates antibiotics into the medium.
B) enhances the growth of normal flora.
C) prevents the growth of Neisseria gonorrhoeae, but promotes the growth of Neisseria
meningitidis.
D) prevents the growth of Neisseria meningitides, but promotes the growth of Neisseria
gonorrhoeae.
As oxygen appeared in the atmosphere, ________ also accumulated, which formed a
protective barrier that protects the Earth from ________.
A) ozone / UV radiation
B) elemental sulfur / volcanism
C) ferrous iron / hydroxylating radicals
D) sulfate / hydrogen sulfide
Which of the following are NOT found within the photosynthetic gene cluster of
Rhodobacter (a purple phototrophic bacterium)?
A) genes encoding reaction center and light-harvesting photocomplexes
B) genes encoding proteins involved in phycobiliprotein biosynthesis
C) genes encoding proteins involved in bacteriochlorophyll biosynthesis
D) genes encoding proteins involved in carotenoid biosynthesis
Why are some xenobiotics biodegraded slower than crude oil and petroleum products?
A) Xenobiotics were designed to inhibit microbial growth.
B) Some xenobiotics are novel compounds that differ from naturally occurring
chemicals, thus microorganisms have not yet evolved to effectively degrade them.
C) Only cometabolic microbial processes degrade xenobiotics.
D) Chlorinated compounds are so toxic that biodegradation is not possible.
From the aquatic systems below, where are heterotrophic Bacteria the MOST
abundant?
A) coastal waters
B) deep sea
C) Sargasso Sea
D) open ocean
Cloning vectors can be distinguished from expression vectors by
A) carrying ori genes for replication of the cloned sequence.
B) having a multiple cloning site (MCS).
C) having a high copy number per cell.
D) lacking a promoter site upstream of the insertion site.
Endolithic phototrophic communities are MOST common in ________ environments.
A) dry
B) hot
C) humid
D) windy
A bacterium running low on NADPH could ________ to generate more of this
coenzyme.
A) degrade an amino acid or nucleic acid
B) invoke the pentose phosphate pathway
C) degrade a fatty acid
D) use a broad specificity phosphatase with inorganic phosphatase and NADH
Chocolate agar is an example of a ________ medium.
A) selective
B) general-purpose
C) nonselective enriched
D) differential
The core genome of a prokaryotic species is the genomic content that is
A) unique compared to all other prokaryotes.
B) expressed under all environmental conditions.
C) shared between all other prokaryotes.
D) shared between all strains of a species.
Which aquatic habitat contains a pelagic zone?
A) estuary
B) lake
C) salt marsh
D) open ocean
Which of the following statements is TRUE about HIV infections?
A) The viral nucleocapsid of the virus enters the host cell when the viral and host
membranes fuse.
B) T-helper cells are greatly reduced in number.
C) The cDNA can integrate into the host chromosome.
D) All of these statements are true.
The rapid increase in adaptive immunity after a second antigen exposure is called
A) immune memory.
B) specificity.
C) tolerance.
D) immune memory, specificity, or tolerance.
The principle behind a nucleic acid probe design is that the probe itself must contain
A) a key complementary part of the target gene sequence of interest.
B) all of the nucleotide sequence of the gene of interest to conclusively identify the
gene.
C) an antibody to specifically bind to the gene of interest.
D) at least three separate complementary regions of the gene of interest.
Virulence is the relative ability of a ________ to cause disease.
A) pathogen
B) commensal
C) virus
D) bacterium
It is difficult to estimate when cyanobacteria appeared on Earth using evidence from the
oxidation state of the Earth’s crust, because
A) several abiotic reactions could have formed Fe3+.
B) there are multiple forms of anoxygenic photosynthesis.
C) there are multiple groups of oxygenic photosynthetic bacteria.
D) several ancient anaerobic metabolisms form Fe3+.
An open reading frame (ORF) encodes for
A) a carbohydrate.
B) a polypeptide.
C) mRNA.
D) a carbohydrate or a polypeptide.
Which method requires the addition of at least one radioactive chemical?
A) CARD-FISH
B) MAR
C) NanoSIMS
D) SIP
A plasmid may
A) replicate independently of the chromosome.
B) be transferred cell-to-cell during conjugation.
C) be integrated into the chromosome.
D) replicate independently of the chromosome, integrate into the chromosome, or be
transferred cell-to-cell during conjugation.
Interpreting stable isotopic fractionation depends on the fact that most enzymes
preferentially bind ________ isotope substrates over ________ isotope substrates.
A) nonradioactive / radioactive
B) light / heavy
C) heavy / light
D) radioactive / nonradioactive