Differential selection and reproduction of phenotypes occurs during a process called
A) cellular differentiation.
B) evolution.
C) growth.
D) transformation.
Transfer RNA molecules
A) function to transfer ribonucleotides to RNA polymerase during transcription.
B) function to transfer the correct amino acids to the ribosome during translation.
C) contain codons that bind to ribosomes during translation.
D) are only present in the nucleus or eukaryotes.
Microbial cells first evolved on Earth approximately ________ billion years ago.
A) 1.6 to 1.8
B) 3.8 to 3.9
C) 5.4 to 5.6
D) 7.0 to 7.2
A fungal mycelium is a large accumulation of ________, which may appear dusty or
fuzzy due to the presence of ________.
A) coenocytes / conidia
B) coenocytes / mycorrhizae
C) hyphae / conidia
D) hyphae / mycorrhizae
Of the following, which is the MOST common AIDS-associated opportunistic disease?
A) Pneumocystis carinii pneumonia
B) cryptosporidiosis
C) histoplasmosis
D) cryptococcosis
Which of the following is associated with mucosa-associated lymph tissue that
produces IgA?
A) breast milk
B) red blood cells
C) blood serum
D) small intestine
Which of the following human mutations correlates with resistance to plasmodial
infections in West Africa?
A) hemoglobin S
B) one particular MHC class I gene
C) one particular set of MHC class II genes
D) hemoglobin S and particular class I and class II genes
The causative agent of Hansen’s disease is
A) Mycobacterium marinum.
B) Mycobacterium ulcerans.
C) Mycobacterium hansen.
D) Mycobacterium leprae.
Severe cases of Staphylococcus aureus food poisoning may require treatment
A) with powerful antibiotics.
B) for dehydration.
C) with cleansing enemas.
D) for dehydration, along with powerful antibiotics and cleansing enemas.
ETEC strains produce one of two heat-________ diarrhea-producing ________.
A) stable / endotoxins
B) labile / endotoxins
C) stable / enterotoxins
D) labile / enterotoxins
In just over a decade of efforts, the World Health Organization (WHO) eradicated
smallpox by using worldwide
A) education campaigns.
B) destruction of infected domestic animals.
C) education campaigns and destruction of infected domestic animals.
D) vaccination programs.
Pickling is a type of food preservation utilizing
A) weak acids.
B) basic substances.
C) lyophilization.
D) irradiation.
Which group of organisms is difficult to control through immunization because of their
rapid and unpredictable genetic mutations?
A) vector-borne organisms
B) RNA viruses
C) Archaea
D) DNA viruses
Which of the following is NOT a staphylococcal disease?
A) acne
B) boils
C) strep throat
D) meningitis
The phage Mu
A) has a circular genome.
B) repairs mutations in the host genome.
C) replicates by transposition.
D) has a circular genome, repairs host genome mutations, and can replicate by
transposition.
In cases of suspected foodborne or waterborne infections, fecal samples should be
inoculated into a variety of selective media.
Microbial immobilization is the best strategy for uranium bioremediation, because
A) uranium is difficult to chemically oxidize.
B) uranium contamination is widespread and thus difficult to physically remove.
C) the by-products of chemical immobilization are toxic.
D) immobilization may only be temporary.
Obligate anaerobes can often use ________ electropositive redox couples than
facultative anaerobes, and ________ metabolism is most common in this group as well.
A) lower / assimilative
B) lower / dissimilative
C) higher / assimilative
D) higher / dissimilative
How is drug-resistant Neisseria gonorrhoeae treated?
A) with penicillinase-resistant β-lactams
B) with tetracycline
C) with synthetic analogs of tetracycline
D) with vancomycin
In comparison to bacteria that do have cell walls, ________ is a consequence of
mycoplasmas lacking a cell wall.
A) larger cytoplasmic volume
B) frequent existence as obligate symbionts
C) higher sensitivity to osmotic lysis
D) inability to survive protoplasts lysing conditions
Serious acute cases of diphtheria are treated with antibiotics and
A) diphtheria antitoxin.
B) diphtheria toxin.
C) diphtheria toxoid.
D) diphtheria antitoxin, diphtheria toxin, and diphtheria toxoid.
Which of the following is a cause of drug-specific resistance in disease-causing
organisms?
A) inappropriate hygiene
B) nosocomial infection
C) poor immunity
D) indiscriminate nonmedical use of antimicrobials
During DNA replication Okazaki fragments are linked together by________, an
enzyme that creates phosphodiester bonds between nicked fragments of DNA.
A) exopolymerase
B) DNA gyrase
C) topoisomerase
D) DNA ligase
In all cells, genes are composed of
A) nucleic acids.
B) mRNA.
C) proteins.
D) chaperones.
Which of the following statements is TRUE concerning mRNA?
A) mRNA has a very short half-life.
B) mRNA has complex secondary structure.
C) mRNA is catalytic.
D) mRNA is the product of translation.
When compared with Bacteria, species of Archaea seem to devote a higher percentage
of their genomes to genes encoding proteins involved in
A) transcription.
B) energy and coenzyme production.
C) cell membrane functions.
D) carbohydrate metabolism.
________ formed the semipermeable membrane-like surfaces for the earliest life forms.
A) Proteins
B) Hydrogen sulfide
C) Lipid bilayers
D) RNA
In the process of transcription, promoters are specific sequences of ________ that are
recognized by ________.
A) DNA / DNA polymerase
B) RNA / DNA polymerase
C) DNA / sigma factors
D) RNA / ribosomes
Organisms such as Streptococcus pyogenes and Staphylococcus aureus that produce
leukocidins are called ________ pathogens.
A) pyogenic
B) radical
C) enterotoxigenic
D) hemorrhagic
Which of the following traits do ammonia and nitrite oxidizers share?
A) chemoorganotrophic
B) autotrophic
C) aerobic
D) autotrophic and aerobic
TC cells express a(n) ________ protein co-receptor.
A) CD4
B) CD8
C) IgM
D) IgG
A notorious biofilm former implicated in cystic fibrosis is
A) Bacillus subtilis.
B) Escherichia coli.
C) Lactobacillus acidophilus.
D) Pseudomonas aeruginosa.
The following is the sequence of bases in the sense strand of a DNA segment and
contains the beginning of a gene.
DNA 3′ A T A T T A C C A G G C A T G G A C C C C C G G G 5′
Based on this sequence, write the sequence of the anti-sense DNA strand and the
mRNA. Label the 5′ and 3′ ends in your predicted sequences. The start codon in this
organism is AUG. Indicate where the start codon is in your sequence. Why is the start
codon important? Why does there have to be a specific start codon?
Bioluminescent microorganisms are found in which of the following groups?
A) Firmicutes
B) Thaumarchaeota
C) Gammaproteobacteria
D) Verrucomicrobia
How is the activity of a riboswitch controlled?
A) by other riboswitches
B) metabolite binding can change its structure
C) sigma factor binding alters its structure
D) small RNA complementary binding disrupts its function