The single most important physical sign of primary syphilis is
A) the chancre.
B) a skin rash.
C) paralysis.
D) an acute eye infection.
Coccolithophores and foraminiferans both use ________ to form their exoskeletons.
A) Si4+
B) Fe3+
C) Ca2+
D) HPO4–
Which of the following is a mechanism of aminoglycosides?
A) inhibition of cell wall biosynthesis
B) prevention of peptidoglycan crosslinking
C) inhibition of DNA replication
D) targeting the 30S ribosomal subunit
RNA-Seq analysis is a method aimed at defining a(n)
A) metabolome.
B) transcriptome.
C) interactome.
D) metagenome.
Isonicotinic acid hydrazide (INH) is an antibiotic used in the treatment of tuberculosis.
It affects the synthesis of
A) mycolic acid.
B) linoleic acid.
C) globular proteins of the cell membrane.
D) DNA transcription.
The burning of fossil fuels produces significant amounts of
A) sulfate.
B) sulfite.
C) sulfonate.
D) sulfur dioxide.
Viral size is generally measured in
A) micrometers.
B) picometers.
C) nanometers.
D) centimeters.
What is the purpose of synthesizing a negative strand RNA in positive stranded ssRNA
viruses?
A) enable rolling circle amplification of the genome, which requires both strands of
RNA
B) enable transcription of genes occurring on both the negative and positive strands of
the genome, such as overlapping genes
C) proofreading of the genome to minimize mutations generated by the polymerase
being passed onto virion progeny
D) to serve as the complementary template sequence in genome amplification of the
positive strand
Consider conjugation in Escherichia coli. In which of the following matings would
chromosomal genes be transferred most frequently?
A) F+ F–
B) F– F–
C) Hfr F–
D) Hfr F+
In an agar dilution tube, microbial colonies grow
A) at the bottom of the tube.
B) on the sides of the tube, although some may be at the surface.
C) embedded in the agar, rather than growing on the surface.
D) on the surface, but some creep down the sides away from the surface.
Pathogenicity is the ability
A) of the host to inflict damage on the pathogen.
B) of the host to resist damage by the pathogen.
C) of the pathogen to inflict damage on the host.
D) None of these are correct.
The process by which antibodies block interactions between pathogens or their products
and host cells is termed
A) attenuation.
B) complement.
C) interference.
D) neutralization.
The virus repressor protein
A) controls the prophage’s lytic genes but not the incoming genomes of the same virus.
B) does not control the prophage’s lytic genes but does control the incoming genomes
of the same virus.
C) controls both the lytic genes on the prophage and prevents an incoming virus of the
same type.
D) has different actions in different situations.
The majority of basidiomycetes living in soil occur as
A) diploid mycelia.
B) diploid basidiocarps.
C) haploid mycelia.
D) haploid basidiocarps.
Staphylococcus aureus is known to cause ALL of the following diseases EXCEPT
A) acne.
B) arthritis.
C) boils.
D) dental caries.
Another name for programmed cell death is
A) necrosis.
B) perforation.
C) apoptosis.
D) cellular degradation.
Hydrolytic enzymes function in the
A) initial degradation of nutrients.
B) transport of substrates within the cell.
C) chemotactic response, particularly in gram-negative Bacteria.
D) regeneration of the periplasm.
All Hfr strains integrate into the chromosome at
A) the same locus.
B) several specific sites.
C) the same locus most of the time, although there may be some variation.
D) loci that cannot be accurately determined.
A chemoorganotroph and a chemolithotroph in the same environment would NOT
compete for
A) oxygen.
B) carbon.
C) nitrogen.
D) phosphorous.
What two gases were most abundant on early Earth?
A) O2 and CO2
B) N2 and H2
C) CO2 and H2
D) CO2 and N2
The most common infectious disease(s) is/are
A) gonorrhea.
B) influenza.
C) hepatitis.
D) colds.
You are looking at a sample from the top green layer of a colorful bacterial mat. Using
phase contrast and fluorescence microscopy, you see evenly spaced cells in the middle
of a filament that are slightly smaller than the others. The smaller cells are not
fluorescent, indicating they lack photosystem II, but the rest of the filament is
fluorescent. What type of filamentous bacteria are you most likely looking at?
A) purple nonsulfur bacteria
B) green sulfur bacteria
C) Acidobacteria
D) Cyanobacteria
A bacterium that catabolizes a compound by linking ion pumps to establish a proton or
sodium motive force for energy
A) can circumvent substrate-level and oxidative phosphorylation.
B) makes insufficient energy to grow but enough for cellular maintenance to survive.
C) requires a second bacterium to cooperatively drive the gradient.
D) still requires another carbon substrate to provide a carbon source.
The Embden-Meyerhof-Parnas pathway is another name for
A) the citric acid cycle.
B) glycolysis.
C) electron transport.
D) NADH production.
One of the more formidable obstacles to mammalian gene cloning is the presence of
A) introns.
B) exons.
C) repressors.
D) integrators.
The initial infective stage of the malarial parasite is the
A) sporozoite.
B) merozoite.
C) schizont.
D) plasmodyite.
The Tat system is involved in
A) protein synthesis.
B) transcriptional initiation.
C) protein folding.
D) protein secretion.
Mutation rates are similar in Bacteria and Archaea, yet certain stressful conditions
mutation rates increase. Why is the mutation rate not constant and close to zero all of
the time?
A) Increased mutation rates can be advantageous in rapidly changing environments
because some random mutations may be useful for survival.
B) Microorganisms carefully control the mutation rate of their DNA to match the
environmental conditions and maximize evolution.
C) The increased mutation rate under stressful conditions is an indication that the
microorganisms can no longer replicate their DNA properly and are about to die.
D) Constant mutation rates would halt evolution completely.
The key characteristic of third-generation sequencing is the ability to sequence single
molecules of DNA.
An example of correct nucleotide pairing is
A) T and U.
B) G and U.
C) A and T.
D) C and U.
Microbial ecology is the study of
A) microbial processes in the rhizosphere that benefit plant growth.
B) the diversity and activities of microorganisms.
C) the grouping and classifying of microorganisms.
D) microorganisms in their natural environments.
What growth conditions would you use to enrich for ammonia-oxidizing bacteria?
A) aerobic mineral media with ammonia and bicarbonate incubated in the dark
B) anaerobic mineral media with acetate and ammonia incubated in the dark
C) aerobic mineral media with acetate and ammonia, incubated in the dark
D) anaerobic mineral media with ammonia and nitrate incubated in the dark
Rheumatic fever is
A) an autoimmune disease.
B) a poststaphylococcal disease.
C) triggered by cell-surface antigens on Staphylococcus aureus cells that are similar to
heart valve and joint antigens.
D) caused by human papillomavirus.