CH17, CH18, Ch 19, Ch 20, Ch 21, Ch 22, Ch 23, Ch 24, Ch 25, Ch 26, Ch 27
4) Which of the following types of metabolisms is NOT found in Archaea? A) Photosynthesis B) Chemolithotrophy C) Chemoorganotrophy D) Aerobic respiration
A) Photosynthesis
61) The invariant amino acids in each peptide motif bound by MHC proteins are called A) anchor residues. B) MHC peptides. C) antigen-binding immunoglobulins. D) TCR peptides.
A) anchor residues.
34) Reductive dechlorination is important in the breakdown of chlorinated xenobiotics because A) anoxic conditions develop rapidly in polluted habitats. B) reductive dechlorination breaks down all halogen compounds. C) aerobic breakdown of xenobiotics is not possible under any circumstances. D) these compounds do not leach into groundwater or sediment.
A) anoxic conditions develop rapidly in polluted habitats.
15) Immunoglobulins are produced by B cells and are also known as A) antibodies. B) antigens. C) bacteria. D) pathogens.
A) antibodies.
21) Adaptive immune responses are directed at pathogen molecules called A) antigens. B) antibodies. C) T cell receptors. D) pathogen-associated molecular pattern (PAMP).
A) antigens.
29) A serum containing antigen-specific antibodies is called an A) antiserum. B) antitoxin. C) anti-antigen. D) anticoagulase.
A) antiserum.
34) The largest reservoir of methane is found A) as methane hydrates trapped under permafrost and marine sediments. B) in the rumen of cows and other ruminant animals. C) in the atmosphere in gaseous form. D) trapped in volcanic rocks in tropical environments around the world.
A) as methane hydrates trapped under permafrost and marine sediments.
36) The C domain of antigen-binding proteins functions to A) attach the antigen-binding domain to the cytoplasmic membrane. B) bind to the cytoplasmic membrane of foreign cells. C) complex multiple antigen-binding proteins together. D) bind to epitopes
A) attach the antigen-binding domain to the cytoplasmic membrane.
8) During secondary aerobic wastewater treatment, some of the activated sludge goes ________ while the rest goes ________. A) back to the aerator / to the anoxic sludge digester B) back to the primary system / to the aerator C) to the anoxic digester / back to the primary system D) back to the primary system / to the tertiary digester
A) back to the aerator / to the anoxic sludge digester
17) An organism living in the bottommost region of a body of water is described as being A) benthic. B) litoral. C) neritic. D) pelagic.
A) benthic.
5) The function of leghemoglobin in root nodules is to A) bind oxygen. B) chelate iron. C) produce iron. D) produce nitrogen.
A) bind oxygen.
14) The measurable strength of the binding of an antibody to antigen is called A) binding affinity. B) epitope. C) tolerance. D) virulence.
A) binding affinity.
5) Stem cells are produced and developed in the A) bone marrow. B) brain. C) liver. D) stems of plants.
A) bone marrow.
49) Human activities have disrupted the carbon cycle by A) burning carbon stored as fossil fuels or biomass, thus increasing the amount of carbon dioxide in the atmosphere. B) decreasing the primary productivity of the oceans, resulting in increased atmospheric carbon dioxide. C) burning methane hydrates to produce electricity. D) acidifying the ocean, resulting in the release of large amounts of dissolved carbon dioxide into the atmosphere.
A) burning carbon stored as fossil fuels or biomass, thus increasing the amount of carbon dioxide in the atmosphere.
17) An outer coat consisting of a dense, well-defined polymer layer surrounding a cell and used in attachment is called a A) capsule. B) cytoplasmic membrane. C) lipopolysaccharide layer. D) pilus.
A) capsule.
22) The calcium cycle is tightly coupled to the A) carbon cycle through calcium carbonate formation in ocean waters. B) phosphorus cycle through calcium phosphate formation in sediments and rocks. C) silica cycle through calcium silicate formation in coastal ocean sediments. D) nitrogen cycle because nitrogenase requires calcium ions.
A) carbon cycle through calcium carbonate formation in ocean waters.
12) Oomycetes (ʺwater moldsʺ) contain ________ in their cell walls, while most fungi have ________ in their cell walls. A) cellulose / chitin B) chitin / cellulose C) silica / chitin D) cellulose / silica
A) cellulose / chitin
26) Many archaeal hyperthermophiles are ________; however, Staphylothermus is a chemoorganotroph. A) chemolithotrophs B) mixotrophs C) parasites D) photoheterotrophs
A) chemolithotrophs
21) All Prochlorococcus strains contain the pigments A) chlorophylls a and b, but not phycobilins. B) chlorophyll a and phycobilins, but not chlorophyll b. C) chlorophyll b and phycobilins, but not chlorophyll a. D) chlorophylls a and b and phycobilins.
A) chlorophylls a and b, but not phycobilins.
28) One of the earliest diverging lineages of fungi is the A) chytridiomycetes. B) zygomycetes. C) glomeromycetes. D) ascomycetes.
A) chytridiomycetes.
28) One factor that seems to aid in maintaining lipid stability in hyperthermophilic Archaea is that biphytanyl tetraether lipids form a(n) A) covalently bonded monolayer cytoplasmic membrane. B) interlocking bilayer cytoplasmic membrane. C) interlocking lattice with the cell wall. D) pseudomembrane immediately inside the cytoplasmic membrane.
A) covalently bonded monolayer cytoplasmic membrane.
40) Extensive microbial growth in a thick bacterial layer on the teeth is called A) dental plaque. B) dental caries. C) dental biofilm. D) periodontitis.
A) dental plaque.
7) Tetanus toxin causes A) muscles to be unable to relax. B) muscles to be unable to contract. C) severe diarrhea. D) hemolytic uremic syndrome.
A) muscles to be unable to relax.
21) Which group of amoebozoans is most likely to cause illness in humans? A) Dictyostelium B) Entamoebas C) Gymnamoebas D) Slime molds
B) Entamoebas ----- parasite
21) Which archaeal phylum contains many extreme halophiles, methanogens, some marine hyperthermophiles, and Thermoplasma? A) Crenarchaeota B) Euryarchaeota C) Nanoarchaeota D) Thaumarchaeota
B) Euryarchaeota
48) ________ are toxic proteins released from the pathogen during normal growth. A) Endotoxins B) Exotoxins C) Macrotoxins D) Microtoxins
B) Exotoxins
46) ________ are cytotoxins produced by T cells that cause apoptosis. A) Perforins B) Granzymes C) Phagocytes D) Macrophages
B) Granzymes
16) Which algae are most closely related to plants? A) Red algae B) Green algae C) Brown algae D) Euglenoids
B) Green algae
36) The most common electron donor used among hyperthermophilic Archaea is A) Fe+3. B) H2. C) SO4. D) S0.
B) H2.
27) Which of the following is NOT an example of an AB toxin? A) Shiga-like toxin B) Hemolysins C) Botulinum toxin D) Tetanus toxin
B) Hemolysins
23) Which of the following is an important factor in the development of dental caries? A) High salt diet B) High sugar diet C) High acid diet D) Low salt diet
B) High sugar diet
34) Thermostable proteins tend to have additional features that improve thermostability. Which of the following is NOT one of these features? A) Increased ionic interactions on the protein surfaces B) Highly hydrophilic cores C) Decreased tendency of the protein to unfold D) Highly hydrophobic cores
B) Highly hydrophilic cores
12) Which of the following is NOT an immunoglobulin? A) IgA B) IgC C) IgD D) IgG
B) IgC
34) Which of the following is a way to prevent attenuation and maintain virulence in a bacterium? A) Laboratory subculture B) Inoculating an animal with the bacterium C) Polymerase chain reaction (PCR) D) Antibiotic therapy
B) Inoculating an animal with the bacterium
9) Which approach would help to identify biologically produced sulfur in a sediment sample? A) Enrichment B) Isotopic fractionation C) Microautoradiography D) Microelectrodes
B) Isotopic fractionation
58) Bioluminescent bacteria convert chemical energy to light energy. What enzyme catalyzes the luminescence reaction? A) luxCDABE B) Luciferase C) Luciferin D) LuxR
B) Luciferase
33) ________ in saliva cleaves glycosidic linkages in the peptidoglycan that is present in bacterial cell walls, weakening the wall and potentially causing cell lysis. A) Mucus B) Lysozyme C) Fibrin D) Lipid A
B) Lysozyme
11) Which method requires the addition of at least one radioactive chemical? A) CARD-FISH B) MAR C) GeoChips D) SIP
B) MAR
43) Why are some xenobiotics biodegraded slower than crude oil and petroleum products? A) Xenobiotics were designed to inhibit microbial growth. B) Microorganisms have not yet evolved to effectively degrade novel xenobiotic compounds. C) Only cometabolic microbial processes degrade xenobiotics. D) Chlorinated compounds are so toxic that biodegradation is not possible.
B) Microorganisms have not yet evolved to effectively degrade novel xenobiotic compounds.
27) Which study set out to generate genomic sequences from 200 strains of bacteria isolated from the human body? A) The Human Microbiome Project B) NIH JumpStart Program C) MetaGenoPolis D) The Integrative Human Microbiome Project
B) NIH JumpStart Program
2) Which of the following represents increasing microbial diversity? A) Guild-community-population B) Population-guild-community C) Cell-community-population D) Community-guild-population
B) Population-guild-community
29) What bacterial population does NOT dominate the gastric fluid? A) Firmicutes B) Proteobacteria C) Bacteroidetes D) Actinobacteria
B) Proteobacteria
33) What is the largest carbon reservoir on Earth? A) Terrestrial biosphere B) Rocks and sediments C) Aquatic biosphere D) Fossil fuels
B) Rocks and sediments
14) Microbes are involved in which step(s) of wastewater treatment? A) Primary only B) Secondary and tertiary C) Secondary only D) Primary and secondary
B) Secondary and tertiary
20) What phenomenon accounts for the appearance of chloroplasts in some unicellular phototrophic eukaryotes? A) Transformation of hydrogenosomes B) Secondary endosymbiosis of green or red algae C) Primary endosymbioses of green or red algae D) Horizontal gene transfer
B) Secondary endosymbiosis of green or red algae
25) Which genus produces hyaluronidase? A) Mycobacterium B) Streptococcus C) Shigella D) Procholorococcus
B) Streptococcus
53) Which one of the following statements is TRUE about the anaerobic oxidation of methane? A) Methanotrophic Archaea can oxidize the methane to CO2 alone. B) Sulfate-reducing bacteria in association with methanotrophic Archaea carry out the reaction. C) Methyl-coenzyme M deactivates the alkanes. D) Ethyl-coenzyme M activates the alkanes.
B) Sulfate-reducing bacteria in association with methanotrophic Archaea carry out the reaction.
20) Antigen-presenting cells present antigens to A) B lymphocytes. B) T lymphocytes. C) dendritic cells. D) neutrophils.
B) T lymphocytes.
66) In B cell selection and tolerance, if no signal is generated from ________ cells, the B cells remain unresponsive. A) Tc B) Th C) B7 D) CD28
B) Th
32) What are activity measurements? A) Activity measurements are any measurements taken in vitro. B) Activity measurements are any measurements taken in situ. C) Activity measurements are collective estimates of the physiological reactions in an entire microbial community. D) Activity measurements are an example of metagenomics, which can be used when genetic analysis is difficult.
C) Activity measurements are collective estimates of the physiological reactions in an entire microbial community.
38) Which of the following bacterial phyla is represented by the greatest diversity of phylotypes on the skin? A) Bacteroides B) Firmicutes C) Actinobacteria D) Proteobacteria
C) Actinobacteria
25) Proteins derived from infecting viruses are taken up and digested in the cytoplasm in a structure called the A) phagosome. B) liposome. C) proteasome. D) nucleosome.
C) proteasome.
18) Capsules are particularly important for A) making bacteria more vulnerable to host defense mechanisms. B) making bacteria less pathogenic. C) protecting bacteria from host defense mechanisms. D) allowing bacteria to become more phagocytic.
C) protecting bacteria from host defense mechanisms.
20) Opportunistic pathogens such as Legionella, Pseudomonas, and Mycobacterium species have the ability to grow within ________, which may enhance their ability to survive in water distribution systems. A) human saliva B) fish C) protists D) UV irradiated water
C) protists
4) Blood and lymph have the following in common EXCEPT A) nucleated cells. B) proteins. C) red blood cells. D) None of these.
C) red blood cells.
30) What is the minimum concentration of sodium chloride that an extreme halophile requires for growth? A) 1.5 M B) 4 M C) 6 M D) 10 M
A) 1.5 M
12) Only particles smaller than ________ μm in diameter reach the lungs. A) 10 B) 20 C) 30 D) 40
A) 10
55) ________ is a group of sequentially interacting proteins important in innate and adaptive immunity. A) A complement B) An opsonin C) An inflammation D) A regeneration
A) A complement
30) Which is an example of acquisition of natural passive immunity? A) A fetus protected from disease by its mother's antibodies B) A person who received his or her yearly influenza vaccine C) A person who acquired the chickenpox D) A person who received tetanus antiserum after stepping on a rusty nail
A) A fetus protected from disease by its mother's antibodies
26) Which of the following is TRUE about research on the human microbiome? A) Advanced nucleic acid sequencing techniques were needed before a good understanding of its microbial abundance and diversity could be developed. B) Culture-dependent techniques fully elucidated its microbial diversity. C) Cultivation was unimportant in studying its microbial diversity. D) None of the answers are correct.
A) Advanced nucleic acid sequencing techniques were needed before a good understanding of its microbial abundance and diversity could be developed.
15) Children with severe dental caries tend to have elevated levels of all of the following bacteria EXCEPT A) Aestuariimicrobium. B) Streptococcus. C) Granulicatella. D) Actinomyces.
A) Aestuariimicrobium.
6) Most haloarchaea use which of the following for electron donors? A) Amino acids and organic acids B) Carbohydrates C) Lipids D) Nucleic acids
A) Amino acids and organic acids
19) Which are the most dominant chemolithotrophs in pelagic waters? A) Ammonia-oxidizing Archaea B) Ammonia-oxidizing Bacteria C) Sulfate-reducing Bacteria D) Prochlorococcus
A) Ammonia-oxidizing Archaea
22) How can the amoebozoans and radiolarians be distinguished from each other with microscopy? A) Amoebozoans have lobe-shaped pseudopodia, radiolarians have threadlike pseudopodia, and radiolarians have radial symmetry. B) Amoebozoans have lobe-shaped pseudopodia, amoebozoans have radial symmetry, and radiolarians have unusually large, thick pseudopodia. C) Amebozoans have large but thin pseudopodia and radiolarians have thick, lobe-shaped pseudopodia. D) Amebozoans have radial symmetry and threadlike pseudopodia, whereas radiolarians have lobe-shaped pseudopodia.
A) Amoebozoans have lobe-shaped pseudopodia, radiolarians have threadlike pseudopodia, and radiolarians have radial symmetry.
8) The photosynthetic pigments bacteriorhodopsin and proteorhodopsin are present in ________ and ________, respectively. A) Archaea / Bacteria B) Bacteria / Archaea C) Bacteria / Bacteria D) Bacteria / Eukarya
A) Archaea / Bacteria
29) Which of the following interact with toll-like receptors (TLRs)? A) Bacterial LPS B) Immunoglobulins C) Major histocompatibility complex proteins D) None of these
A) Bacterial LPS
42) How is vaginosis diagnosed? A) Based on a microscopic scoring of a Gram-stained vaginal smear B) Based on clinical manifestations observed by a physician C) By checking vaginal pH using a pH test strip D) By performing a colposcopy
A) Based on a microscopic scoring of a Gram-stained vaginal smear
18) Which of the following is the most common probiotics? A) Bifidobacterium species B) Clostridium species C) Escherichia coli D) Corynebacterium species
A) Bifidobacterium species
11) Where are ectomycorrhizae most highly developed? A) Boreal and temperate forests B) Tundra C) Tropical dry forests D) Tropical rain forests
A) Boreal and temperate forests
28) Which of the following fluids contains secretory IgA? A) Breastmilk B) Blood serum C) Urine D) Lymph
A) Breastmilk
18) What would a fucoxanthin carotenoid stain be most useful in identifying? A) Brown or golden algae B) Flagellated algae C) Photosynthetic diatoms D) Slime molds from other molds
A) Brown or golden algae
22) How do treatment systems select for granular sludge formation? A) By removing suspended floc material that does not settle rapidly B) By using phosphorus-accumulating organisms to generate PHA C) By spraying wastewater over bed of rocks D) By a series of grates and screens
A) By removing suspended floc material that does not settle rapidly
45) Transcription of various genes under particular environmental conditions in natural populations can be studied using A) CARD-FISH. B) stable isotope analysis. C) T-RFLP. D) green fluorescent protein (GFP).
A) CARD-FISH.
8) Th cells express a ________ protein coreceptor. A) CD4 B) CD8 C) CD12 D) T cell receptor
A) CD4
26) Which is the most toxic form of mercury in animals? A) CH3Hg+ B) Hg0 C) Hg2+ D) Hg4+
A) CH3Hg+
54) Chemokines produced by activated macrophages include A) CXCL8. B) TNF-α. C) interleukin-4. D) interleukin-5.
A) CXCL8.
42) ________ use inorganic electron donors released from deep-sea hydrothermal vents. A) Chemolithotrophs B) Photoheterotrophs C) Chemoheterotrophs D) Photolithotrophs
A) Chemolithotrophs
7) Which of the following are found on the surfaces of all nucleated cells? A) Class I MHC proteins B) Class II MHC proteins C) G proteins D) M proteins
A) Class I MHC proteins
31) A species of insect that lives solely on pinesap was found to contain a bacterial symbiont. Genome sequencing of both the host and the symbiont revealed that the symbiont lacked many genes required for energy production, and the host lacked genes for biosynthesis of several essential amino acids. What is/are the most likely mechanism(s) that caused the loss of these genes? A) Coevolution B) Horizontal gene transfer C) Increased mutation rate D) Horizontal gene transfer and increased mutation rate
A) Coevolution
49) Which of the following is a category of exotoxin? A) Cytolytic toxin B) Lipophilic toxin C) α-toxin D) β-toxin
A) Cytolytic toxin
7) Which of the following cell types has NO nucleus? A) Erythrocytes B) Lymphocytes C) Phagocyte D) All of these cells lack a nucleus.
A) Erythrocytes
22) What makes the metabolism of Ferroglobus interesting in the context of evolution? A) Ferroglobus is an anaerobic iron-oxidizing chemolithotrophic autotroph that may represent a key metabolism that allowed for the oxidation of ferrous iron without molecular oxygen. B) Ferroglobus can use H2 or H2S as electron acceptors in its energy metabolism and is thermophilic, thus representing the earliest hypothesized forms of life. C) Ferroglobus lacks cell walls and becomes encrusted in oxidized iron, suggesting that it may be an ancestor of other archaeans that lack cell walls. D) Ferroglobus is both an iron- and nitrate-reducer and is probably the last common ancestor of all iron- and nitrate-reducing organisms.
A) Ferroglobus is an anaerobic iron-oxidizing chemolithotrophic autotroph that may represent a key metabolism that allowed for the oxidation of ferrous iron without molecular oxygen.
44) The most abundant prokaryotic organism in the ocean is of the genus A) Pelagibacter. B) Puniceispirillum. C) Roseobacter. D) Prochlorococcus.
A) Pelagibacter.
26) Which of the following is more likely to cause urinary tract infections? A) Fimbriated strains of Escherichia coli B) Nonfimbriated strains of Escherichia coli C) Both fimbriated and nonfimbriated strains of Escherichia coli D) None of the answers are correct.
A) Fimbriated strains of Escherichia coli
41) What happens when mice grown in the absence of microbes are inoculated with healthy fecal material from other mice? A) Genes associated with glucose uptake, lipid absorption, and lipid transport are activated and the mice gain body fat without increasing energy intake. B) Genes associated with glucose uptake, lipid absorption, and lipid transport are activated and the mice gain body fat as a result of taking in more food. C) Genes associated with protein uptake, lipid breakdown, and lipid transport are activated and the mice lose body fat without changing their food intake. D) Genes associated with protein uptake, lipid breakdown, and lipid transport are deactivated and the mice lose body fat as a result of taking in less food.
A) Genes associated with glucose uptake, lipid absorption, and lipid transport are activated and the mice gain body fat without increasing energy intake.
1) The microorganisms that are thought to resemble the first cellular forms of life on Earth are A) H2-oxidizing hyperthermophiles. B) acidophilic Archaea. C) the Nanoarchaeota. D) fermentative thermophiles.
A) H2-oxidizing hyperthermophiles.
47) Riftia tube worms contain unusual hemoglobins that bind A) H2S and O2 in order to transport these chemicals to their bacterial symbionts. B) high concentrations of O2 produced by their photosynthetic symbionts. C) sulfate to transport this ion away from their bacterial symbionts. D) ammonia that their bacterial symbionts produce.
A) H2S and O2 in order to transport these chemicals to their bacterial symbionts.
29) Which of the following are important adaptations specific to herbivores? A) Having a large, anoxic chamber where fermentation can occur and having an extended retention time for food B) Having a large, oxic chamber where fermentation can occur and having an extended retention time for food C) Having a large, anoxic chamber where fermentation can occur and having relatively rapid food passage through the digestive tract D) Having a large, oxic chamber where fermentation can occur and having relatively rapid food passage through the digestive tract
A) Having a large, anoxic chamber where fermentation can occur and having an extended retention time for food
50) ________ are microbial infections acquired by hospital patients with noninfectious diseases because they are compromised hosts. A) Healthcare-associated infections B) Immunocompromised infections C) Pathogenic infections D) Virulent infections
A) Healthcare-associated infections
7) Which of these microorganisms is most likely to be found in the human stomach? A) Helicobacter pylori B) Streptococcus sobrinus C) Streptococcus mutans D) Roseobacter denitrificans
A) Helicobacter pylori
1) ________ is a term used to describe dead organic matter. A) Humus B) Loam C) Pyrite D) Xenocompost
A) Humus
51) Which of the following cytokines is produced by Th1 cells for growth and activation of other T cells? A) IL-2 B) IL-4 C) IL-5 D) IL-2, IL-4, and IL-5
A) IL-2
14) Which statement is TRUE regarding the ecological role of plant degradation by fungi? A) In brown rot, the cellulose is attacked preferentially, and the lignin is left unmetabolized. B) In brown rot, the lignin is attacked preferentially, and the cellulose is left unmetabolized. C) In white rot, the cellulose is attacked preferentially, and the lignin is left unmetabolized. D) In white rot, the lignin is attacked preferentially, and the cellulose is left unmetabolized.
A) In brown rot, the cellulose is attacked preferentially, and the lignin is left unmetabolized.
48) 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.
A) Incubate the sample with 13C-methane.
41) Which of the following is a major growth-limiting micronutrient that influences microbial growth? A) Iron B) Water C) Vitamin K D) Sugar
A) Iron
39) The ribosomes of Halobacterium require high ________ levels for stability and activity. A) KCl B) NaCl C) NaSO4 D) acidic amino acid
A) KCl ----- halophiles = halobacterium
14) Which of the following hemolysins is a phospholipase? A) Lecithinase B) Streptolysin-O C) Staphylococcal α-toxin D) Leukocidin
A) Lecithinase
22) Which of the following is NOT important for the adherence of bacteria to host tissues? A) Lipopolysaccharides B) Capsule C) Adhesins D) Slime layer
A) Lipopolysaccharides
32) Halobacterium salinarum and certain other extreme halophiles carry out light-driven synthesis of ATP under what condition? A) Low oxygen concentrations B) Low light C) High oxygen concentrations D) High carbon dioxide concentrations
A) Low oxygen concentrations
21) Which disease CANNOT be prevented via the use of a vaccine generated from an attenuated pathogen? A) Malaria B) Measles C) Mumps D) Rubella
A) Malaria
20) From the aquatic systems below, where are heterotrophic Bacteria the most abundant? A) Marine coastal waters B) Deep sea C) Sargasso Sea D) Open ocean
A) Marine coastal waters
20) Which genus within Archaea is capable of growth at the hottest temperature recorded of 122°C? A) Methanopyrus B) Thermoproteus C) Thermosphaera D) Pyrococcus
A) Methanopyrus
31) What is the major reservoir of stable nitrogen? A) N2 B) NO C) NO3- D) NH4
A) N2
27) What chemical initiates the formation of acid mine drainage when pyrite is not disposed of properly? A) O2 B) Fe2+ C) HS- D) SO42-
A) O2
25) Which of the following is the first, or initiator, reaction in acid mine drainage and leaching? A) Oxidation of reduced sulfides to sulfate and the release of reduced iron (Fe2+) B) Rapid spontaneous reduction of oxidized iron (Fe3+) C) Rapid oxidation of sulfides to sulfate by oxidized iron (Fe3+) D) Microbial sulfate reduction
A) Oxidation of reduced sulfides to sulfate and the release of reduced iron (Fe2+)
35) ________ are the main primary producers in freshwater environments. A) Phototrophic microorganisms B) Heterotrophic microorganisms C) Chemolithotrophic microorganisms D) Viral microorganisms
A) Phototrophic microorganisms
16) According to bacterial abundance studies done so far on soils, the ________ represent the most abundant phylum. A) Proteobacteria B) Acidobacteria C) Actinobacteria D) Firmicutes
A) Proteobacteria
17) How does Pseudomonas aeruginosa transfer electrons extracellularly to reduce iron? A) Pyocyanin B) Humic substances C) Pili D) Flavin mononucleotide (FMN)
A) Pyocyanin
25) ________ is a strict anaerobe with irregularly disc-shaped cells and an optimum growth temperature of 105°C. It grows chemolithotrophically on H2 with S0 as an electron acceptor or chemoorganotrophically on complex mixtures of organic compounds. A) Pyrodictium B) Pyrolobus C) Pyrobaculum D) Desulfurococcus
A) Pyrodictium
8) Shiga toxin is an enterotoxin that is produced by A) Shigella dysenteriae. B) Clostridium tetani. C) Escherichia coli O157:H7. D) Vibrio cholerae.
A) Shigella dysenteriae.
1) Which metric describes the proportion of EACH species present in a community? A) Species abundance B) Species diversity C) Species evenness D) Species richness
A) Species abundance
25) 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
A) T cells
43) Which of the following is NOT true of human gut microbes? A) The population size is low, but the diversity is high. B) They produce and excrete amino acids. C) They help utilize polysaccharides. D) They are involved in the "maturing" of the digestive tract.
A) The population size is low, but the diversity is high.
15) What special adaptation(s) has/have Thermoplasma evolved to survive in hot, acidic environments? A) Thermoplasma stabilize their cytoplasmic membrane by incorporation of tetraether lipoglycans in the cytoplasmic membrane. B) Thermoplasma have a reinforced cell wall containing basic amino linkers in the peptidoglycan. C) Thermoplasma excrete hydrogen ions and import hydroxyl ions. D) Thermoplasma are highly motile to avoid destruction.
A) Thermoplasma stabilize their cytoplasmic membrane by incorporation of tetraether lipoglycans in the cytoplasmic membrane.
34) 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) They both use lipochitin oligosaccharide signaling factors to initiate root colonization.
17) What is the role of fecal transplants in medicine? A) They can provide a healthy microbiota to help treat Clostridium difficile infections. B) They act as prebiotics to encourage healthy microbial growth. C) They can be used to treat infections caused by Vibrio cholerae. D) They can be used to treat infections caused by the overgrowth of Lactobacilli.
A) They can provide a healthy microbiota to help treat Clostridium difficile infections.
22) Which of the following is TRUE of vaginal bacterial communities? A) Those dominated by Lactobacillus crispatus are more resilient than those dominated by Lactobacillus iners. B) Those dominated by Lactobacillus crispatus are less resilient than those dominated by Lactobacillus iners. C) Lactobacillus iners is always associated with vaginosis, but Lactobacillus crispatus is not. D) Lactobacillus crispatus is always associated with vaginosis, but Lactobacillus iners is not.
A) Those dominated by Lactobacillus crispatus are more resilient than those dominated by Lactobacillus iners.
44) African sleeping sickness is caused by A) Trypanosoma brucei. B) Giardia intestinalis. C) Trichomonas vaginalis. D) Plasmodium sp.
A) Trypanosoma brucei.
8) A thin, crescent-shaped organism with a single flagellum originating from a basal body and which folds back laterally across the cell would most likely be a member of the genus A) Trypanosoma. B) Glossina. C) Entamoeba. D) Gambiense.
A) Trypanosoma.
14) What is the difference between vaginitis and vaginosis? A) Vaginitis is more serious and vaginosis is subclinical. B) Vaginosis is more serious and vaginitis is subclinical. C) Vaginosis occurs first and then develops into vaginitis. D) Vaginosis is an acute infection and vaginitis is always a chronic infection.
A) Vaginitis is more serious and vaginosis is subclinical.
40) Which of the following pathogens does NOT use capsules or a slime layer for attachment? A) Vibrio cholera B) Streptococcus pneumonia C) Bacillus anthracis D) All of these pathogens use capsules or slime layers for attachment.
A) Vibrio cholera
6) A cross-reaction is an interaction between an antibody or TCR and A) a heterologous antigen. B) a homologous antigen. C) either a heterologous or homologous antigen. D) None of these are correct.
A) a heterologous antigen.
38) For a pure culture of Saccharomyces cerevisiae cells that were all derived from a single cell to mate, A) a mating-type switch in one or more cells in the culture must occur. B) both the α and the a gene must be fully expressed in the initial population. C) the α gene must be fully repressed in the population. D) some cells must exist as diploids.
A) a mating-type switch in one or more cells in the culture must occur.
50) The first cell type active in the innate response is usually A) a phagocyte. B) an erythrocyte. C) a fibroblast. D) an antibody.
A) a phagocyte.
45) Septicemia is an example of A) a systemic infection. B) a transient infection. C) a localized infection. D) an autoimmune infection.
A) a systemic infection.
40) Lysis of marine algae and cyanobacteria releases a major osmoregulatory solute, dimethylsulfoniopropionate (DMSP), which is degraded into the most abundant organic S compound in nature, A) dimethyl sulfide (CH3-S-CH3). B) hydrogen sulfide (H2S). C) gypsum (CaSO4). D) elemental sulfur (S0).
A) dimethyl sulfide (CH3-S-CH3).
17) Endolithic phototrophic communities are most commonly found in ________ environments. A) dry B) hot C) humid D) windy
A) dry
7) In a stratified lake, the warmer and less dense layer is called the A) epilimnion. B) hypolimnion. C) metalimnion. D) thermocline.
A) epilimnion.
5) The part of the antigen recognized by the antibody or TCR is called the A) epitope. B) antigen-binding site. C) antigenic complex. D) light chain.
A) epitope.
2) 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.
A) extracellular pathogens.
37) Infants born via C-section have A) fewer Bacteroides species than those born vaginally. B) approximately 72% of the species present matching those of their mothers. C) relatively less Staphylococcus aureus than those born vaginally. D) fewer Veillonella species than those born vaginally.
A) fewer Bacteroides species than those born vaginally.
20) Clostridium difficile infections most often occur A) following antibiotic treatment. B) following a fecal transplant. C) following a dietary change. D) following the use of a new probiotic.
A) following antibiotic treatment.
37) Water in the rocks and soils of Earth's subsurface is called A) groundwater. B) surface water. C) subsurface water. D) deep water.
A) groundwater.
31) A population of metabolically related microorganisms is called a(n) A) guild. B) niche. C) ecosystem. D) haplotype.
A) guild.
8) The cytoplasmic proteins of Halobacterium are A) highly acidic. B) highly basic. C) generally neutral. D) variable, depending on the species.
A) highly acidic.
23) The antigen that induces an antibody or TCR is called the A) homologous antigen. B) heterologous antigen. C) cross-reactive antigen. D) immunogenic antigen.
A) homologous antigen.
57) The major histocompatibility complex in humans is also called the A) human leukocyte antigen (HLA). B) T cell receptor. C) toll-like receptor complex. D) T cell receptor or toll-like receptor.
A) human leukocyte antigen (HLA).
41) Crenarchaeotes whose optimal growth temperature is over 80°C are called A) hyperthermophiles. B) thermophiles. C) extreme halophiles. D) halophiles.
A) hyperthermophiles.
11) 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.
A) immune memory.
21) Substances that induce an immune response are known as A) immunogens. B) antigens. C) immunoglobulins. D) antigen-presenting cells.
A) immunogens.
49) Epibionts of "Chlorochromatium aggregatum" can transfer nutrients to the central bacterium only A) in the presence of light and sulfide. B) in the presence of α-ketoglutarate. C) in the presence of light and α-ketoglutarate. D) in the presence of glutamate synthase.
A) in the presence of light and sulfide.
3) With increased levels of oxidizable materials, the biochemical oxygen demand (BOD) will A) increase. B) decrease. C) remain the same. D) increase or decrease depending on the nature of the materials involved.
A) increase.
50) The small ribosomal rRNA gene sequences of hyperthermophilic Archaea and Bacteria have relatively high GC content, which A) increases stability at high temperatures because GC pairs are joined by 3 hydrogen bonds. B) decreases stability at high temperatures because GC pairs are joined by 2 hydrogen bonds. C) increases mutation rates at high temperatures compared with other rRNA. D) due to considerable variation in their GC content, makes this unhelpful as a distinguishing feature between them and nonhyperthermophilic Archaea and Bacteria.
A) increases stability at high temperatures because GC pairs are joined by 3 hydrogen bonds.
38) Some of the cytokines produced by lymphocytes are called A) interleukins. B) pathogen recognition receptors. C) complement. D) epitopes.
A) interleukins.
24) Treatment of drinking water by UV irradiation is effective at ________, but is less effective at ________. A) killing bacteria and some cysts / killing viruses B) killing viruses / killing bacteria and eukaryotic pathogens C) removing odor- and taste-altering organic compounds / killing bacteria D) killing bacteria and viruses / killing eukaryotic pathogens
A) killing bacteria and some cysts / killing viruses
16) Individuals who have chronic periodontitis tend to have A) lower microbial diversity than those without. B) significantly greater microbial diversity than those without. C) slightly greater microbial diversity than those without. D) unpredictable levels of microbial diversity in comparison to those without chronic periodontitis.
A) lower microbial diversity than those without.
12) Secondary disinfection of drinking water is necessary to A) maintain sufficient residual in the water distribution system to inhibit microbial growth. B) completely prevent the formation of biofilms on pipes in the water distribution system. C) neutralize taste- and odor-producing organic compounds. D) kill Cryptosporidium and other resistant pathogens.
A) maintain sufficient residual in the water distribution system to inhibit microbial growth.
44) Aliivibrio fischeri symbionts benefit the Hawaiian bobtail squid by A) mimicking the light of the moon, which helps the squid avoid nocturnal predators. B) providing essential amino acids missing from the squid's diet. C) degrading the cellulosic cell walls of the phytoplankton the squid eats. D) providing essential amino acids missing from the squid's diet and degrading the cellulosic cell walls of the phytoplankton the squid eats.
A) mimicking the light of the moon, which helps the squid avoid nocturnal predators.
33) The transfer of antibodies through the placenta from mother to fetus is an example of A) natural passive immunity. B) innate immunity. C) natural active immunity. D) artificial active immunity
A) natural passive immunity.
20) It is thought that attenuation occurs especially in a laboratory setting because A) nonvirulent or weakly virulent mutants grow faster in laboratory media when there is no selective advantage to virulence. B) pathogens lose virulence with age and survive longer in laboratory cultures. C) patients can be treated with drugs that induce attenuation. D) there is selection for more virulent strains in the laboratory.
A) nonvirulent or weakly virulent mutants grow faster in laboratory media when there is no selective advantage to virulence.
44) Studying the redox cycling of Fe in the environment has led to the discovery A) of bacteria that transfer electrons as a form of electricity. B) of bacteria that destroy toxic metal ions. C) of archaea that have Fe in their cell walls. D) that Fe limits primary production in terrestrial ecosystems.
A) of bacteria that transfer electrons as a form of electricity.
41) 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
A) oxalic acid / fungi
43) The best term to describe the general process by which microorganisms cause diseases is known as A) pathogenesis. B) virulence. C) invasion. D) infection.
A) pathogenesis.
37) Pathogenicity and virulence differ in that A) pathogenicity refers to the overall ability of a microbe to cause disease, whereas virulence refers to the ability of one microbe to cause disease relative to another. B) virulence refers to the overall ability of a microbe to cause disease, whereas pathogenicity refers to the ability of one microbe to cause disease relative to another. C) pathogenicity only refers to pathogens, whereas virulence refers to any microbe that can cause an infection. D) virulence only refers to pathogens, whereas pathogenicity refers to any microbe that can cause an infection.
A) pathogenicity refers to the overall ability of a microbe to cause disease, whereas virulence refers to the ability of one microbe to cause disease relative to another.
26) T cell-target cell interactions induce specialized Tc cells to produce ________ that kill virus-infected target cells. A) perforins B) granulozymes C) leukocidins D) pyogens
A) perforins
23) Phosphorus reservoirs include A) phosphate minerals in rocks, dissolved phosphates in aquatic environments, and the nucleic acids and phospholipids of living organisms. B) mineral phosphonates and the nucleic acids and phospholipids of living organisms. C) elemental phosphorus minerals and phosphonates. D) elemental phosphorus, polyphosphate, and phosphonates.
A) phosphate minerals in rocks, dissolved phosphates in aquatic environments, and the nucleic acids and phospholipids of living organisms.
34) Thirty organisms containing the same phylogenetic marker, with identical or similar orthologous genes, are all considered to be within the same A) phylotype. B) species. C) functional group. D) phylogenetic tree.
A) phylotype.
67) Some activated B cells differentiate into ________ cells that secrete antibodies, and others into ________ cells. A) plasma / memory B B) lymphocytes / memory B C) immunoglobulin / plasma D) immunoglobulin / Th
A) plasma / memory B
39) Two major environmental extremes of the deep sea are high ________ and low ________. A) pressure / nutrient levels B) nutrient levels / pressure C) temperature / pressure D) oxygen / pressure
A) pressure / nutrient levels
10) Methanogens A) produce methane as a part of their energy metabolism. B) utilize methane as an energy source. C) process and store methane to detoxify it. D) produce, utilize, and detoxify methane.
A) produce methane as a part of their energy metabolism.
48) The bioenergetics of anaerobic respiring Archaea, such as those of the Crenarchaeota, involve ________ from which ________ is synthesized. A) proton-translocating ATPases / ATP B) substrate level phosphorylation / ATP C) sodium translocation / ATP D) substrate level phosphorylation / GTP
A) proton-translocating ATPases / ATP
54) Organisms such as Streptococcus pyogenes and Staphylococcus aureus that produce leukocidins and are associated with pus are called ________ pathogens. A) pyogenic B) radical C) enterotoxigenic D) hemorrhagic
A) pyogenic
24) The Fe and Mn cycles include A) reduced and oxidized forms that are very chemically reactive. B) large reservoirs of solid mineral forms that are chemically inert. C) incorporation of Fe and Mn into the exoskeletons of diatoms and other alga. D) toxic forms that can poison aquatic ecosystems if the cycles are imbalanced.
A) reduced and oxidized forms that are very chemically reactive.
16) Influenza virus targets A) respiratory epithelium. B) gastrointestinal cells. C) oral cavity cells. D) throat epithelium.
A) respiratory epithelium.
14) Phylogenetic stains, such as those used in phylogenetic FISH, hybridize with A) ribosomal RNA. B) mitochondrial DNA. C) nuclear DNA. D) RNA polymerase.
A) ribosomal RNA.
8) Normal microbiota in the duodenum is A) similar to the microbiota in the stomach. B) dominated by aerobic organisms. C) tolerant to highly alkaline environments. D) tolerant to high salinity.
A) similar to the microbiota in the stomach.
29) The greenhouse effect is caused by gases A) such as CO2, CH4, and N2O that trap infrared radiation, heating the Earth. B) such as CO2 that increase plant and animal growth, resulting in more heat production on Earth. C) such as CO2 and O3 (ozone) that interact with UV light and heat the Earth. D) such as CO2, CH4, and N2O that destroy O3 (ozone) and allow more UV light to enter the atmosphere, thus increasing the temperature of the Earth's surface.
A) such as CO2, CH4, and N2O that trap infrared radiation, heating the Earth.
42) Lichens are a mutualistic association of a fungus and either an alga or a cyanobacterium in which A) the fungus protects the photosynthetic partner from erosion. B) the fungus slowly engulfs the photosynthetic partner. C) the fungus helps collect sunlight for the photosynthetic partner. D) the phototroph provides phosphorus to the fungus.
A) the fungus protects the photosynthetic partner from erosion.
32) The collective term for the functional collection of microbes living on or in the human body, as opposed to a general term for organisms in an environmental habitat, is A) the human microbiome. B) the microbiota. C) transient microbial flora. D) pathogens.
A) the human microbiome.
32) The collective term for the organisms living on or in the human body, as opposed to a general term for organisms in an environmental habitat, is A) the human microbiome. B) the microbiota. C) transient microbial flora. D) pathogens.
A) the human microbiome.
20) When dealing with stable isotopes of carbon and sulfur, enzymes tend to favor A) the lighter isotope. B) the heavier isotope. C) the isotopes in about equal proportions. D) either the lighter or the heavier isotope, depending on environmental conditions.
A) the lighter isotope.
38) In mycorrhizal mutualisms between plants roots and fungi, A) the plant supplies carbohydrates to the fungus and the fungus supplies phosphorus and nitrogen to the plant. B) the plant supplies water to the fungus and the fungus supplies essential amino acids to the plant. C) the plant protects the fungus from predation and the fungus supplies carbohydrates to the plant. D) the fungus infects the plant roots, stimulating plant growth through Myc factors that act as growth hormones in the plant.
A) the plant supplies carbohydrates to the fungus and the fungus supplies phosphorus and nitrogen to the plant.
36) The signaling factors of arbuscular mycorrhizae most likely gave rise to the signaling factors used in rhizobial nodule formation, yet less is known about arbuscular mycorrhizae because A) they cannot be maintained in pure culture. B) they are not as important for plant health. C) no genetic systems have been developed for fungi. D) they are not as important for plant health and no genetic systems have been developed for fungi.
A) they cannot be maintained in pure culture.
15) Salmonella species use ________ to facilitate attachment to gastrointestinal tissue. A) type I fimbriae B) antiphagocytic proteins C) siderophores D) pili
A) type I fimbriae
39) Diversity is often ________ when T-RFLP is used. A) underestimated B) overestimated C) randomly overestimated or underestimated D) impossible to estimate
A) underestimated
22) Symbionts such as Rickettsia in whiteflies and Buchnera in aphids 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
A) vertically to offspring
42) An epitope is ________ amino acid(s) long. A) 1 B) 10-15 C) 50-60 D) 700
B) 10-15
35) What is thought to be the maximum temperature for life to exist? A) 125°C B) 150°C C) 250°C D) 500°C
B) 150°C
28) Why is it necessary to have a standard for the interpretation of stable isotope ratios? A) A standard is necessary to calculate how rapidly the stable isotopes undergo radioactive decay. B) A standard is necessary to determine the stable isotope ratio in the absence of biological activity. C) A standard is necessary because samples are only presented in comparison with other samples of the same age. D) A standard is necessary to determine the age of the sample.
B) A standard is necessary to determine the stable isotope ratio in the absence of biological activity.
14) Which compounds serve as major sources of energy for ruminant animals? A) Acetic acid and glucose B) Acetic, butyric, and propionic acids C) Dimethylsulfoniopropionate, gluconate, and protocatechuate D) Glucose and sucrose
B) Acetic, butyric, and propionic acids
18) Under which condition is ferrous iron (Fe2+) not spontaneously oxidized? A) Neutral pH B) Acidic pH C) Iron rich D) Manganese rich
B) Acidic pH
33) ________ dominate the infant gut microbiota. A) Candida B) Actinobacteria C) Firmicutes D) Corynebacteria
B) Actinobacteria
9) Which bacterium contains a large Ti plasmid and causes crown gall disease in plants? A) Agrobacterium rhizogenes B) Agrobacterium tumefaciens C) Aliivibrio fischeri D) Butyrivibrio fibrisolvens
B) Agrobacterium tumefaciens
64) ________ ensures that each B cell produces only one immunoglobulin. A) Self-activation B) Allelic exclusion C) MHC interaction D) Clonal deletion
B) Allelic exclusion
50) What is the difference between animal viruses and bacteriophages? A) An animal virus has two lifestyles, while a bacteriophage has only one. B) An animal virus has four lifestyles, while a bacteriophage has two. C) An animal virus can follow either lytic or lysogenic lifestyle, while a bacteriophage follows only lytic. D) Both an animal virus and a bacteriophage can use lytic or lysogenic lifestyles.
B) An animal virus has four lifestyles, while a bacteriophage has two.
47) Which of the following hypotheses could be tested using microautoradiography fluorescence in situ hybridization (MAR-FISH)? A) Bacteriorhodopsin uses light energy to translocate protons. B) Archaea are the main autotrophs in marine water samples taken 300 m below the surface of the ocean. C) The microbial community of agricultural soils is more phylogenetically diverse than the microbial community of native prairie soils. D) The ammonia monooxygenase gene is present in members of the phylum Verrucomicrobium.
B) Archaea are the main autotrophs in marine water samples taken 300 m below the surface of the ocean.
19) Which of the treatments listed below would be most effective for a patient with a genetic defect that causes severe combined immunodeficiency (SCID), a condition in which there is a severe deficiency in B and T lymphocytes? A) Intravenous antibiotics B) Bone marrow transplant C) Multiple immunizations D) Repeated doses of antisera
B) Bone marrow transplant
6) The following bacterial genera are all implicated in dental caries EXCEPT A) Fusobacterium. B) Borrelia. C) Streptococcus. D) Corynebacterium.
B) Borrelia.
27) Tc cells express a(n) ________ protein co-receptor. A) CD4 B) CD8 C) IgM D) IgG
B) CD8
30) What are the most abundant biomolecules in a typical fungal cell wall? A) Amino acids B) Carbohydrates C) Lipids D) Porins and channels
B) Carbohydrates ---- chitin
41) What are the two main groups of green algae? A) Chlorophytes and chrysophytes B) Chlorophytes and charophyceans C) Chrysophytes and charophyceans D) Chlorarachniophytes and chlorophytes
B) Chlorophytes and charophyceans
14) Which is the correct order of increasing size in soil particles? A) Clay - sand - silt B) Clay - silt - sand C) Sand - clay- silt D) Silt - clay - sand
B) Clay - silt - sand
23) Which of the following do dinoflagellates most commonly associate with in a mutualistic relationship? A) Clams B) Corals C) Flatworms D) Snails
B) Corals
15) Which of the following is the name of the heavy chain constant domain of an IgD antibody? A) Beta B) Delta C) Zeta D) Rho
B) Delta
32) Which of the following is an example of a biofilm? A) Transient skin microbes B) Dental plaque C) Marine diatoms D) A planktonic microcolony
B) Dental plaque
15) What is the primary product when dimethylsulfoniopropionate (DMSP) is aerobically degraded in a marine environment? A) Acrylate B) Dimethyl disulfide C) Dimethyl sulfoxide D) Methanethiol
B) Dimethyl disulfide
14) In most salt lakes, which microbial group is the major oxygenic phototroph? A) Cyanobacteria B) Dunaliella, a eukaryotic alga C) Halophilic Archaea D) Purple nonsulfur bacteria
B) Dunaliella, a eukaryotic alga
12) How do arbuscular mycorrhizae (AM) help plants obtain more nutrients from the soil? A) By-products of AM metabolism serve as primary nutrient sources for the plants. B) The AM increase the total surface area to absorb more nutrients. C) The hyphae develop as specialized nodules that directly produce nutrients for the plant. D) Signaling molecules in the plant are passed to the AM to initiate electron flow, which is in turn used to create ATP.
B) The AM increase the total surface area to absorb more nutrients.
34) Which of the following is TRUE about the comparison between the mouse gut and the human gut? A) The stomach is relatively larger in mice. B) The colon and cecum are relatively larger in mice. C) The small intestine is relatively larger in mice. D) The esophagus and stomach are relatively larger in mice.
B) The colon and cecum are relatively larger in mice.
27) Which statement is TRUE about the fluid from the hydrothermal vents? A) The fluid contains large amounts of oxidized inorganic materials. B) The fluid contains large amounts of reduced inorganic materials. C) The fluid contains large amounts of organic material. D) The fluid usually contains about equal amounts of organic and inorganic material.
B) The fluid contains large amounts of reduced inorganic materials.
2) Which statement is TRUE of methanogenic and extremely halophilic Archaea? A) The methanogens are obligate aerobes; the extreme halophiles are obligate anaerobes. B) The methanogens are obligate anaerobes; the extreme halophiles are mostly obligate aerobes. C) Both the methanogens and the extreme halophiles are obligate aerobes. D) Both the methanogens and the extreme halophiles are obligate anaerobes.
B) The methanogens are obligate anaerobes; the extreme halophiles are mostly obligate aerobes.
31) Which of the following is a reason that specific pathogens tend to infect specific tissues? A) Some tissues have receptors for microbes, but others do not. B) There are chemical and physical differences between tissues. C) Tissues with neutral pH are colonized but those with acidic or alkaline pH are not. D) Microbes preferentially target external tissues, such as skin, as the environment is more favorable for their growth than inside the body.
B) There are chemical and physical differences between tissues.
23) How does the concentration of prokaryotic cells at the surface of pelagic water compare with the concentrations at depths below 1000 m? A) There is a decrease in concentration from 1 m to 1000 m in depth, then a dramatic increase below 1000 m. B) There is a decrease in concentration with increasing depth. C) There is a steady increase in concentration with increasing depth. D) There is an increase in concentration at depths below 1000 m.
B) There is a decrease in concentration with increasing depth.
23) Which of the following is TRUE regarding the interaction between hormones and vaginal microbial diversity? A) There is a direct relationship between estradiol levels and microbial diversity. B) There is an inverse relationship between estradiol levels and microbial diversity. C) There is a direct relationship between luteinizing hormone levels and microbial diversity. D) There is an inverse relationship between luteinizing hormone levels and microbial diversity.
B) There is an inverse relationship between estradiol levels and microbial diversity.
6) Which of the following is NOT true about breastfed infants compared with those given formula milk? A) They have greater numbers of Bifidobacterium longum. B) They have greater numbers of Clostridioides difficile. C) They have greater numbers of Lactobacillus spp. D) They have greater numbers of Staphylococcus epidermidis.
B) They have greater numbers of Clostridioides difficile.
10) An endogenous pyrogen is A) a chemical from the bacterial cell wall that causes fever. B) a chemical produced by a host's own immune system that causes fever. C) a chemical released by a bacterial cell that causes fever. D) a chemical produced within a bacterial cell that is released during cell division or at death of the bacterium, at which point it causes fever.
B) a chemical produced by a host's own immune system that causes fever.
37) When laser tweezers are used, the laser beam can trap A) an isolated single-copy genome in a capillary tube. B) a single microbial cell in a capillary tube. C) a single microbial colony on a plate. D) multiple cells of the same type on a plate.
B) a single microbial cell in a capillary tube.
6) The primary energy source for termites comes from A) acetogenic Archaea. B) acetogenic Bacteria. C) methanogenic Archaea. D) methanogenic Bacteria.
B) acetogenic Bacteria.
10) A population consists of A) all of the individuals of all species in the same area. B) all of the individuals of one species in the same area. C) all of the individuals that interact in different areas. D) all of the individuals that interact in the same area.
B) all of the individuals of one species in the same area.
43) Aphids that feed on carbohydrate-rich but nutrient-poor foods obtain ________ from their endosymbiotic bacterial partners. A) ATP B) amino acids C) ammonium D) volatile fatty acids
B) amino acids
19) The decrease or loss of virulence of a pathogen is referred to as A) aging. B) attenuation. C) disinfectivity. D) lethal dose.
B) attenuation.
47) The condition that results when some bacteria are shed in the bloodstream and distributed to distant parts of the body but do not reproduce in the blood is called A) septicemia. B) bacteremia. C) uremia. D) erythemia.
B) bacteremia.
43) Proteins known as ________ function to refold partially denatured proteins. A) histones B) chaperones C) HU proteins D) histones and chaperones
B) chaperones
16) The use of ________ to treat drinking water, which began in 1913, reduces the incidence of waterborne diseases. A) coagulation B) chlorination C) filtration D) UV irradiation
B) chlorination
10) To further reduce the possibility of biological contamination, most treatment plants treat the effluent with A) fluorine. B) chlorine. C) ozone. D) extreme heat.
B) chlorine.
36) Microsporidia were previously thought to be an early-branching taxon of Eukarya due to their parasitic lifestyle. However, new evidence suggests that they are more closely related to the A) ascomycetes. B) chytridiomycetes. C) glomeromycetes. D) zygomycetes.
B) chytridiomycetes.
47) The two-stage thymic selection process for selecting self-tolerant, antigen-reactive T cells results in A) allelic exclusion. B) clonal deletion. C) complementarity-determining regions. D) somatic hypermutation.
B) clonal deletion.
11) Staphylococcus aureus produces ________, leading to fibrin clots that protect them from attack by host cells. A) collagenase B) coagulase C) lipase D) amylase
B) coagulase
62) Amino acid variability is especially apparent in several ________ in the variable domains of different immunoglobulins. A) heavy chains B) complementarity-determining regions (CDR) C) peptide motifs D) epitopes
B) complementarity-determining regions (CDR)
36) Sudden nutrient perturbations in an environment generally ________ the overall prokaryotic diversity. A) increase B) decrease C) maintain D) replicate
B) decrease
65) The mechanism that selects for antigen-reactive T cells that respond to foreign antigens while ignoring self-antigens is called clonal A) development. B) deletion. C) anergy. D) expansion
B) deletion.
37) During the Jurassic Period, several different mammalian lineages independently evolved an herbivorous lifestyle for obtaining energy. This has resulted in A) different digestive patterns in herbivorous animals, some that depend on gut microbiota to digest plant material and some that do not. B) different digestive patterns in herbivorous animals that all depend on gut microbiota to digest plant material. C) the evolution of foregut fermentation, as seen in ruminants, as the only digestive pattern that depends on fermentative gut microbiota. D) horizontal gene transfer of genes for glycoside hydrolases and polysaccharide lyases from bacteria to mammals.
B) different digestive patterns in herbivorous animals that all depend on gut microbiota to digest plant material.
12) During periods of stratification, transfer between surface and bottom waters is controlled by A) mixing. B) diffusion. C) niche partitioning. D) current.
B) diffusion.
13) 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.
B) discharged from the wastewater treatment facility.
10) Nitrate reduced into ammonia to produce energy for the cell is called A) ammonification. B) dissimilative reduction of nitrate to ammonia (DRNA). C) denitrification. D) the anammox reaction.
B) dissimilative reduction of nitrate to ammonia (DRNA).
44) The human oral microbiota consists of A) a small group of phylogenetically related aerobic microorganisms. B) diverse aerobic and anaerobic microorganisms. C) monoculture biofilms on tooth surfaces. D) the same phyla that are found in the human gut.
B) diverse aerobic and anaerobic microorganisms.
63) The antigen-binding site of an antibody accommodates a small portion of the antigen called a(n) A) lipopolysaccharide. B) epitope. C) peptide motif. D) pathogen associated molecular pattern (PAMP).
B) epitope.
27) The factor that most affects the thermostability of a protein is its A) highly hydrophobic core regions. B) folding pattern. C) ionic surface interactions. D) number of hydrogen bonds.
B) folding pattern.
19) A geologist going through a sediment core is likely to find remnants of ancient calcium carbonate containing ________ and silica containing ________. A) diatoms / chlorarachniophytes B) foraminiferans / diatoms C) chlorarachniophytes / foraminiferans D) foraminiferans / chlorarachniophytes
B) foraminiferans / diatoms
15) For microbial biodiversity studies, it is common to identify the ________ rather than the ________ as a measure of biodiversity. A) organisms themselves / genes B) genes / organisms themselves C) cell types / genes D) cell types / organisms themselves
B) genes / organisms themselves
25) The function of the parabasal body is to A) allow for photosynthesis to occur. B) give structural support to the Golgi complex. C) allow for the formation of energy from aerobic respiration. D) give structural support to the endoflagellum.
B) give structural support to the Golgi complex.
35) Reductive dechlorination is a process in which A) oxygenase enzymes add oxygen to chlorinated compounds. B) halogenase enzymes remove chlorine from chlorinated compounds. C) carbon dioxide is the primary end product. D) only dichloro compounds can be degraded.
B) halogenase enzymes remove chlorine from chlorinated compounds.
32) When squids that contain luminescent bacterial symbionts hatch, they do NOT contain a bacterial symbiont. Symbiont transmission in this symbiosis is A) vertical from parent to offspring. B) horizontal and involves specific selection of the symbiont from the environment. C) random and results in various different species being selected as the symbiont. D) mixed and results in multiple symbiont species colonizing the squid at once.
B) horizontal and involves specific selection of the symbiont from the environment.
1) The ability of humans to resist a disease is called A) dormancy. B) immunity. C) resistance. D) susceptibility.
B) immunity.
20) The body's noninducible, preexisting ability to recognize and destroy a variety of pathogens or their products is called A) adaptive immunity. B) innate immunity. C) phagocytosis. D) cytotoxic response.
B) innate immunity.
37) The main bonds present in the C domain of antigen-binding proteins are A) hydrogen bonds. B) intrachain disulfide bonds. C) ionic bonds. D) van der Waals forces
B) intrachain disulfide bonds.
7) Many parabasalids lack ________, which makes them different than most other eukaryotes. A) endoplasmic reticula B) introns in their genomes C) mitochondria and hydrogenosomes D) Golgi complexes
B) introns in their genomes
8) Laser tweezers are most directly used for A) enriching a culture. B) isolating individual cells. C) increasing magnification. D) enhancing the growth of fastidious organisms.
B) isolating individual cells.
29) One unusual feature of Pyrococcus is that A) it incorporates carbon dioxide via the acetyl-CoA pathway. B) it is very motile due to a tuft of polar archaella. C) it incorporates carbon dioxide via the reverse citric acid cycle. D) it is a thermophilic aerobic chemoorganotroph that uses elemental sulfur.
B) it is very motile due to a tuft of polar archaella
37) Signal transduction pathways initiate activation of transcription after specific A) TH cell death. B) ligand-receptor binding on the cell surface. C) cytokines diffuse across the cytoplasmic membrane. D) antigen-antibody binding.
B) ligand-receptor binding on the cell surface.
33) 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
B) light / heavy
15) Myc factors are A) a type of strigolactone hormone. B) lipochitin oligosaccharide signaling proteins produced by arbuscular mycorrhizae. C) examples of chemicals that mycorrhizae obtain from the soil. D) Carbohydrate structures that form connections between mycorrhizae and plants.
B) lipochitin oligosaccharide signaling proteins produced by arbuscular mycorrhizae.
51) When dendritic cells ingest antigen, they migrate to the ________, where they present the antigen to T lymphocytes. A) kidneys B) lymph nodes C) thymus D) spleen
B) lymph nodes
23) The first defense cells that interact with a pathogen in the body are A) T cells. B) macrophages. C) B cells. D) mast cells.
B) macrophages.
12) Most known methanogens are nonhalophilic A) psychrophiles. B) mesophiles. C) thermophiles. D) extremophiles.
B) mesophiles.
37) The two major forms of carbon that remain following microbial degradation are A) methane, organic matter, and fossil fuels. B) methane and carbon dioxide. C) lignin and fossil fuels. D) organic matter and hydrocarbons.
B) methane and carbon dioxide.
30) Ecological theory states that for every organism there is AT LEAST one ________, and the microenvironment where the organism is most successful is called the ________. A) population / community B) niche / realized niche C) prime niche / niche D) community / population
B) niche / realized niche
21) Bacterial symbionts of termite hindguts play a critical role in the termite's A) reproduction. B) nitrogen metabolism. C) resistance to fungal infection. D) reproduction and nitrogen metabolism.
B) nitrogen metabolism.
45) The enhancement of phagocytosis due to deposition of antibody on the surface of a pathogen or antigen is called A) complementation. B) opsonization. C) inflammation. D) antibody class switching.
B) opsonization.
41) Phosphonate comprises 25% of the ________ phosphorous pool in nature. A) inorganic B) organic C) insoluble D) biologically unavailable
B) organic
47) Nitrification and anammox both A) create nitrogen gas, but nitrification is aerobic while anammox is anaerobic. B) oxidize ammonia, but nitrification uses O2 as an electron acceptor and anammox uses NO2-. C) are aerobic processes, but nitrification produces NO3- and anammox produces N2 gas. D) occur in soils at neutral pH.
B) oxidize ammonia, but nitrification uses O2 as an electron acceptor and anammox uses NO2-.
24) Epsilonproteobacteria are most dominant in hydrothermal vents because they A) reduce nitrogen. B) oxidize sulfide and sulfur as electron donors. C) use oxygen as electron acceptors. D) bind divalent cations.
B) oxidize sulfide and sulfur as electron donors.
1) Microbial leaching of minerals is dependent on how easily the mineral can be A) precipitated. B) oxidized. C) reduced. D) corroded.
B) oxidized.
60) The peptides bound by a single MHC protein share a common A) C domain. B) peptide motif. C) V domain. D) nucleotide sequence.
B) peptide motif.
2) Cells that can engulf foreign particles, and can ingest, kill, and digest most bacterial pathogens are called A) red blood cells. B) phagocytes. C) reticulocytes. D) resistant cells.
B) phagocytes.
36) Microbial plastics are composed of A) polysaccharides. B) polyhydroxyalkanoates (PHAs). C) polyaromatic hydrocarbons. D) xenobiotics.
B) polyhydroxyalkanoates (PHAs).
31) Normal microbiota helps to ________ colonization of pathogenic organisms. A) promote B) prevent C) maintain D) accelerate
B) prevent
45) Potassium cyclic 2,3-diphosphoglycerate is present at concentrations of 1M or more in the cytoplasm of many hyperthermophilic methanogens. The function of this compound is to A) prevent rRNA misfolding. B) prevent chemical damage to DNA at high temperatures. C) introduce supercoils into DNA. D) activate hydrogen gas.
B) prevent chemical damage to DNA at high temperatures.
32) After the first exposure to an antigen, a ________ stimulates growth and multiplication of antigen-reactive cells. A) secondary innate immune response B) primary adaptive immune response C) phagocytic immune response D) hyperactive cytotoxic response
B) primary adaptive immune response
49) Weight gain and obesity may be partly caused by certain gut microbial communities that A) absorb more vitamins and essential amino acids. B) produce more volatile fatty acids by fermentation. C) stimulate the gut endothelium to absorb more sugars. D) produce more hydrogen gas by fermentation.
B) produce more volatile fatty acids by fermentation.
9) The metabolic process of ammonification ________ ammonia. A) oxidizes B) produces C) reduces D) transforms
B) produces
12) Staining methods are suitable for obtaining A) information about physiology from natural samples. B) quantitative information from natural samples. C) phylogenetic information from natural samples. D) neither qualitative nor quantitative information from natural samples.
B) quantitative information from natural samples.
2) 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.
B) remove organic matter.
19) A vaginal microbial community that does not change when exposed to stressors is called A) resilient. B) resistant. C) robust. D) regimented.
B) resistant.
3) A moist microenvironment of the skin produces an oily substance called A) mucus. B) sebum. C) fimbria D) lipid A.
B) sebum.
40) Biomass generation due to heterotrophic organisms is called ________ production. A) primary B) secondary C) auxotrophic D) regulatory
B) secondary
37) Synthetic plastics are A) oxidized completely to carbon dioxide after a few years under aerobic conditions. B) slower to degrade than microbial plastics. C) constructed from PHAs. D) more expensive than microbial plastics.
B) slower to degrade than microbial plastics.
42) Crown corrosion of concrete wastewater distribution systems is the result of A) acidic fermentation products reacting with the gypsum in the concrete. B) sulfate reduction in the sewage and sulfide oxidation in the oxic headspace above. C) fungal growth in the concrete. D) rapid iron reduction coupled to pyrite dissolution.
B) sulfate reduction in the sewage and sulfide oxidation in the oxic headspace above.
3) Staphylococcus aureus and Streptococcus pyogenes strains can produce ________ that cause(s) the severe and sometimes life-threatening symptoms of toxic shock syndrome. A) endotoxin B) superantigen toxins C) AB toxins D) cytolytic
B) superantigen toxins
7) One important difference between the C, N, and S cycles and the P, Ca, and Si cycles is that A) P, Ca, and Si are NOT cycled in terrestrial environments. B) the P, Ca, and Si cycles do NOT involve redox changes or gaseous forms that can alter Earth's atmospheric chemistry. C) the P, Ca, and Si cycles do NOT involve microbial activity. D) the P, Ca, and Si cycles are NOT affected by global warming or other human activity.
B) the P, Ca, and Si cycles do NOT involve redox changes or gaseous forms that can alter Earth's atmospheric chemistry.
28) The propagation cycle that occurs in acid mine drainage is caused by A) reduction of Fe3+ by sulfuric acid. B) the oxidation of FeS2. C) microbial sulfate reduction. D) low pH and high oxygen concentrations.
B) the oxidation of FeS2.
30) Interaction of a pathogen-associated molecular pattern (PAMP) with a pattern recognition receptor (PRR) results in A) formation of transmembrane pores that cause cell lysis. B) transmembrane signal transduction that initiates transcription of genes involved in phagocytosis, inflammation, and pathogen killing. C) molecular activation of the adaptive immune system. D) a superantigen reaction that can cause septic shock
B) transmembrane signal transduction that initiates transcription of genes involved in phagocytosis, inflammation, and pathogen killing.
40) Immunoglobulin G consists of four polypeptides, ________ heavy chains, and ________ light chains. A) one / three B) two / two C) three / one D) four / four
B) two / two
30) Microbial immobilization is the best strategy for uranium bioremediation, because A) uranium is difficult to chemically oxidize. B) uranium contamination is often widespread and thus difficult to physically remove. C) the by-products of chemical immobilization are toxic. D) immobilization may only be temporary.
B) uranium contamination is often widespread and thus difficult to physically remove.
16) Amplification of chromosomal DNA from a single-cell is accomplished by A) using PhyloChips. B) using multiple displacement amplification. C) creating complementary DNA from transcripts of a single-cell. D) cloning fragments of the chromosome from the single-cell into a multi-copy plasmid.
B) using multiple displacement amplification.
10) The following compounds are all produced by intestinal microbiota EXCEPT A) lysine. B) vitamin C. C) vitamin B12. D) vitamin K.
B) vitamin C.
25) Ruminants digest bacterial cells as a primary source of A) carbohydrates. B) vitamins and proteins. C) proteins. D) vitamins.
B) vitamins and proteins.
17) Some members of the Thermoplasmatales can grow at pH levels below A) 4. B) 7. C) 0. D) 10.
C) 0.
46) Viruses in the marine environment typically outnumber prokaryotic cells by a factor of about A) 100 B) 1000 C) 10 D) 10,000
C) 10
26) Genes encoding ________ are widely used as target genes in molecular biodiversity studies. A) ATPases B) DNA polymerase III C) 16S rRNA D) RNA polymerase
C) 16S rRNA
16) Approximately ________ of the Methanocaldococcus jannaschii genes have no counterparts in known genes from other sequenced organisms. A) 10% B) 25% C) 40% D) 70%
C) 40%
17) Which process produces a gaseous product that can be used as fuel to provide heat or power for a wastewater treatment plant? A) Trickling filter secondary wastewater treatment B) Aerobic sludge treatment C) Anaerobic sludge treatment D) Primary wastewater treatment
C) Anaerobic sludge treatment
57) Bacteria such as Aliivibrio produce visible light. What is this process called? A) Luminescence B) Photoluminescence C) Bioluminescence D) Chemiluminescence
C) Bioluminescence
56) 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
C) C domain
6) Which product of anoxic sewage treatment can be used to heat and power an entire water treatment facility? A) CO2 B) H2 C) CH4 D) O2
C) CH4
49) Nitrifying Archaea such as Nitrosopumilus maritimus use ________ as a sole carbon source and are capable of obtaining sufficient energy by aerobically oxidizing ________. A) CO2 / NO B) sugars / ammonia C) CO2 / ammonia D) organic acids / NO
C) CO2 / ammonia
42) Coccolithophores and foraminiferans both use ________ to form their exoskeletons. A) Si4+ B) Fe3+ C) Ca2+ D) HPO42-
C) Ca2+
11) Vaginitis commonly results from overgrowth of A) Candida. B) Trichomonas vaginalis. C) Candida and Trichomonas vaginalis. D) Neither Candida nor Trichomonas vaginalis.
C) Candida and Trichomonas vaginalis.
23) Which microbial group is responsible for massive amphibian die-offs worldwide? A) Cercozoans B) Ciliates C) Chytrids D) Zygomycetes
C) Chytrids
51) Which one of the following viruses can be found in pigs and has the smallest DNA genome? A) Anellovirus B) Adenovirus C) Circovirus D) Polyomavirus
C) Circovirus
49) Which of the following is involved in B cell selection and tolerance? A) Clonal anergy only B) Clonal deletion only C) Clonal anergy and deletion D) Allelic exclusion
C) Clonal anergy and deletion
45) ________ are a main component of chalk deposits found in many regions of the world such as the White Cliffs of Dover, in England. A) Foraminiferans B) Apicomplexans C) Coccolithophores D) Slime molds
C) Coccolithophores
31) Which spores are NOT involved in sexual reproduction of fungi? A) Ascospores B) Basidiospores C) Conidia D) Zygospores
C) Conidia
1) What statement is TRUE about stomach microbiota? A) Few microbes can survive because it is so acidic. B) The alkaline environment supports a wide variety of species. C) Despite the high acidity of the stomach, diverse phylotypes of resident microbes thrive there. D) There is a rich diversity of transient microbes, but few resident microbes.
C) Despite the high acidity of the stomach, diverse phylotypes of resident microbes thrive there.
36) ________ is a damage or injury to a host organism that impairs its function. A) Trauma B) Infection C) Disease D) Transmission
C) Disease
48) The oxidation of ________ occurs both biotically and abiotically, but biotic oxidation is more common at ________ pH values. A) Si / low B) ammonia / high C) Fe2+ / low D) Hg0 / low
C) Fe2+ / low
35) Which of the following is a likely target for a toll-like receptor (TLR)? A) Tumor necrosis factor B) Interleukin IV C) Flagellin D) Insulin
C) Flagellin
56) What are some factors impacting the abundance of bee population? A) Fragmentation of habitats and the use of pesticides B) Climate change and pollution C) Fragmentation of habitats, pesticides, climate change, pollution D) The use of pesticides only
C) Fragmentation of habitats, pesticides, climate change, pollution
6)Which fluorescent molecule enables visualization of living microorganisms? A) Acridine orange B) DAPI C) GFP D) SYBR® Green
C) GFP
16) The fungal division containing arbuscular mycorrhizae is the A) Betaproteobacteria. B) Basidiomycota. C) Glomeromycota. D) Rhizobia.
C) Glomeromycota.
13) Which of the following are NOT substrates for methanogens? A) Acetate and pyruvate B) Carbon dioxide, carbon monoxide, and formate C) Glucose and sucrose D) Methanol and methylamine
C) Glucose and sucrose
35) What are the primary chemical mediators released from mast cells during an immediate-type hypersensitivity reaction? A) Antibodies B) Interleukin I and tumor necrosis factor C) Histamine and serotonin D) Cytokines
C) Histamine and serotonin
53) Which of the following cytokines is produced by macrophages and endothelial cells and acts on natural killer cells and naïve T cells? A) IL-1β B) IL-6 C) IL-12 D) TNF-α
C) IL-12
39) Fever is induced at the systemic level by ________, which is an endogenous pyrogen. A) CXCL8 B) IL-12 C) IL-6 D) CCL2
C) IL-6
24) Which class of antibody activates complement? A) IgA B) IgB C) IgM D) IgC
C) IgM
18) In class switching during the secondary antibody response, the most common antibody switch in serum is from A) IgA to IgD. B) IgD to IgE. C) IgM to IgG. D) None of the answers are correct.
C) IgM to IgG.
33) Laboratory isolation of Nanoarchaeum equitans requires the presence of A) fatty acids. B) oxygen. C) Ignicoccus. D) sunlight.
C) Ignicoccus.
47) Which of the following is NOT a function of the human gut microbiome? A) Production of essential amino acids and vitamins B) Production of volatile fatty acids from polysaccharides C) Iron and trace metal absorption D) Maturation of the gastrointestinal tract
C) Iron and trace metal absorption
42) The dose of an antigen that kills 50% of animals in a test group and is used to estimate the virulence of a pathogen is known as A) antigen dose 50. B) virulence-50. C) LD50 (lethal dose 50). D) death rate-50.
C) LD50 (lethal dose 50).
46) The process by which white blood cells ingest and kill bacteria is called A) exocytosis. B) transcription. C) phagocytosis. D) translation.
C) phagocytosis.
19) What characteristic do bacterial mycoplasmas and the archaeal Thermoplasma and Ferroplasma have in common? A) Contain plasmids B) Hyperthermophilic C) Lack cell walls D) Relatively large genomes from duplicated genes
C) Lack cell walls
15) Which of the following bacterial pathogens is found in water distribution systems? A) Enterobacter aerogenes B) Klebsiella pneumoniae C) Legionella pneumophila D) Vibrio cholerae
C) Legionella pneumophila
48) Streptococcus pyogenes produces proteins called ________, which alter(s) the surface of the pathogen and inhibits phagocytosis. A) glycolipids B) leukocidins C) M proteins D) pus
C) M proteins
11) Which statement BEST describes the habitats of the fungi? A) Most fungi are aquatic, microscopic, and primarily freshwater. B) Most fungi are aquatic and primarily marine. C) Most fungi are terrestrial, microscopic, and inhabit soil or dead plant matter. D) Most fungi are terrestrial and macroscopic.
C) Most fungi are terrestrial, microscopic, and inhabit soil or dead plant matter.
22) Which technique would be used to estimate the concentration of naturally occurring Escherichia coli in a wastewater sample? A) Agar dilution tube method B) Laser tweezers method C) Most probable number (MPN) method D) Cell tagging using GFP method
C) Most probable number (MPN) method
53) Which of the following uses its cell wall glycolipids to absorb hydroxyl radicals and superoxide anions? A) Staphylococcus aureus B) Streptococcus pyogenes C) Mycobacterium tuberculosis D) Escherichia coli
C) Mycobacterium tuberculosis
11) Which compound in fertilizer do farmers use to inhibit the production of easily leached nitrogen compounds? A) Anhydrous ammonia B) Carbonate C) Nitrapyrin D) Nitrate
C) Nitrapyrin
26) What is the key reaction that Acidithiobacillus ferrooxidans catalyzes 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
C) Oxidation of reduced iron (Fe2+) to oxidized iron (Fe3+)
2) Which of the following is/are NOT a degradation product of organic material? A) Carbon dioxide B) Methane C) Oxygen D) All of these answer choices are degradation products of organic material.
C) Oxygen
23) What is necessary in a side stream brine in order to use the anammox process for nitrogen removal? A) Enhanced biological phosphorus removal B) Trickling filter C) Partial nitration D) Chlorination
C) Partial nitration
29) What unit is isotopic fractionation reported as? A) Parts per billion B) Parts per hundred C) Parts per thousand D) Parts per trillion
C) Parts per thousand
23) Which of the following bioenergetic processes CANNOT occur in hyperthermophiles? A) Chemoorganotrophy B) Chemolithotrophy C) Photosynthesis D) Chemoorganotrophy and chemolithotrophy
C) Photosynthesis
5) Which treatment method(s) are used in primary wastewater treatment? A) Biological only B) Chemical only C) Physical separation only D) Biological, chemical, and physical separation
C) Physical separation only
33) Which of the following hydrocarbon compounds are most recalcitrant to degradation during bioremediation, meaning that they stay in the environment longer than the others? A) Straight-chain hydrocarbons B) Methane C) Polycyclic hydrocarbons D) Natural gases such as ethane and propane
C) Polycyclic hydrocarbons
26) Phylogenetic analyses of marine prokaryotic diversity in both shallow and deep-sea marine sediments have found that both types of sediments are dominated by A) Firmicutes. B) Planctomycetes. C) Proteobacteria. D) Chloroflexi.
C) Proteobacteria.
37) Ascospores are produced in all of the following taxa EXCEPT A) Aspergillus. B) Candida. C) Rhizopus. D) Saccharomyces.
C) Rhizopus.
22) Which of the following is NOT an oxygenic phototrophic microorganism present in marine waters? A) Ostreococcus B) Prochlorococcus C) Roseobacter D) Trichodesmium
C) Roseobacter
52) Volatile fatty acids, such as acetate, propionate, butyrate, are produced during the fermentation process in which part of the ruminant's stomach? A) Psalterium B) Abomasum C) Rumen D) Omasum
C) Rumen
11) What is the advantage of enhanced biological phosphorus removal (EBPR) over chemical precipitation? A) Chemical precipitation produces sludge containing arsenic. B) EBPR removes significantly more phosphorus than chemical precipitation. C) Significantly, less sludge is produced by EBPR compared to chemical precipitation. D) EBPR is a more stable process.
C) Significantly, less sludge is produced by EBPR compared to chemical precipitation.
36) Which of the following is known to be TRUE about dog owners and their dogs? A) Dog owners have fewer skin microbes than those who don't own dogs. B) Dog owners have more skin microbes than those who don't own dogs. C) Skin microbes are more common between dog owners and their own dogs than between dog owners and other dogs. D) Skin microbes are similar between dog owners and dogs in general, with no difference in similarity when dogs and their owners are compared with other human-dog pairs.
C) Skin microbes are more common between dog owners and their own dogs than between dog owners and other dogs.
14) What would the result be when a soil is supplemented with S0? A) Dimethyl sulfide production due to mixotrophs B) Organic carbon production due to anaerobes C) Soil acidification due to chemolithotrophs D) Syntrophic utilization of sulfite
C) Soil acidification due to chemolithotrophs
24) Which of the following is NOT a member of the Eukarya? A) Protists B) Fungi C) Spirochetes D) Red algae
C) Spirochetes
46) You would like to test the hypothesis that ammonia-oxidizing Archaea are more active and abundant than ammonia-oxidizing Bacteria in coastal marine water. What technique(s) or experiment(s) could you use to test this hypothesis? A) Environmental proteomics B) Fluorescent in situ hybridization (FISH) C) Stable isotope probing using 15N labeled ammonia D) Stable isotope ratios of ammonia and nitrite
C) Stable isotope probing using 15N labeled ammonia
40) Which group of organisms is thought to be responsible for the corrosion of submerged metal structures and pipelines? A) Fermentative microorganisms B) Acidophilic copper-oxidizers C) Sulfate reducers D) Hydrocarbon-degrading anaerobes
C) Sulfate reducers
24) Which of the following is TRUE about the genera Sulfolobus? A) Sulfolobus grows in sulfur-rich hot alkaline springs. B) Sulfolobus is an anaerobic chemolithotroph. C) Sulfolobus can grow chemoorganotrophically. D) Sulfolobus is a gram-positive rod.
C) Sulfolobus can grow chemoorganotrophically.
10) The unique antigen-reactive proteins of T cells are A) antibodies. B) immunoglobulins. C) T cell receptors. D) None of these are correct.
C) T cell receptors.
69) IL-6 stimulates undifferentiated Th cells to mature and differentiate into which T cell subset? A) Th1 B) Th2 C) Th17 D) Treg
C) Th17
24) What is the primary benefit to phototrophic microorganisms associated with corals? A) Calcium and carbonate ions are released, which help buffer the pH and prevent dramatic pH shifts. B) The coral skeleton is used as a source of bicarbonate for the autotrophic growth of the phototrophs. C) The coral skeleton is an extremely efficient light-gathering structure that greatly enhances light harvesting for photosynthesis. D) The water temperature in and around the coral skeleton is much warmer than elsewhere.
C) The coral skeleton is an extremely efficient light-gathering structure that greatly enhances light harvesting for photosynthesis.
27) How do viability stains usually distinguish between living cells and dead cells? A) The chemical fluoresces only when bound to ribosomes that are actively synthesizing proteins. B) The chemical stain is taken up by living cells and once metabolized becomes fluorescent. C) The dye specifically targets intact cytoplasmic membranes. D) The dye's fluorescence is quenched by dead cells.
C) The dye specifically targets intact cytoplasmic membranes.
6) What is the primary difference between a bacteroid and bacterial cell? A) There are genetic differences that can be detected using 16S rRNA gene sequencing. B) They are biochemically very different from bacterial cells. C) Their cell morphology is different from bacterial morphology. D) They have genetic differences that can be detected using DNA sequencing.
C) Their cell morphology is different from bacterial morphology.
11) What best describes the methanogens? A) They are a monophyletic group. B) They are phylogenetically similar. C) They are a diverse group that is spread across at least eight orders. D) They are a functionally but not phylogenetically diverse group.
C) They are a diverse group that is spread across at least eight orders.
48) Which of the following is TRUE of Riftia tube worm symbionts? A) They have never been maintained in laboratory culture. B) They are obligate symbionts. C) They have a free-living stage. D) They have an unusually small genome, even for a symbiont.
C) They have a free-living stage.
9) Why are bioactive pollutants like prescription medications a challenge for wastewater treatment? A) They are present at high concentrations toxic to microorganisms. B) They are only occasionally found in treated sewage. C) They may not support microbial growth. D) Degradation produces chemicals that are more harmful to the environment.
C) They may not support microbial growth.
3) ________ is the acquired inability to mount an adaptive immune response against self. A) Memory B) Specificity C) Tolerance D) Immunogenicity
C) Tolerance
9) A drug that specifically inhibits the replication of the large DNA mass present in large mitochondria would be most effective at killing A) euglenids. B) ciliates. C) Trypanosoma spp. D) Toxoplasma spp.
C) Trypanosoma spp.
31) Which of these is often used as a prophylactic measure to protect a person against future attack by a pathogen? A) Antiserum injection B) Artificial passive immunity C) Vaccination D) None of these are correct
C) Vaccination
3) Archaea are A) primarily ancient organisms that have not evolved very much in the last billion years. B) phylogenetically diverse, but functionally restricted to extremophiles and chemolithotrophs. C) a group of diverse microorganisms that inhabit almost every environment on Earth, including the colon of humans and other mammals. D) functionally diverse, but restricted to thermophilic or hyperthermophilic environments.
C) a group of diverse microorganisms that inhabit almost every environment on Earth, including the colon of humans and other mammals.
13) The α-toxin of Clostridium perfringens is A) an endotoxin. B) an enterotoxin. C) a lecithinase. D) a superantigen toxin.
C) a lecithinase.
4)Winogradsky columns are used primarily for enrichment of A) aerobic cultures, although occasionally anaerobes do appear. B) anaerobic cultures, although occasionally aerobes do appear. C) aerobes, anaerobes, and phototrophs. D) phototrophs, although occasionally heterotrophs do appear.
C) aerobes, anaerobes, and phototrophs.
29) Organic matter that comes from outside the ecosystem is referred to as ________ organic matter. A) synthropic B) lithotrophic C) allochthonous D) pleomorphic
C) allochthonous
4) Diphtheria toxin is A) a type of endotoxin. B) a cytolytic toxin. C) an AB toxin. D) a superantigen toxin.
C) an AB toxin.
21) Analyses of sulfur isotopes have been used as evidence against life on the Moon, because the sulfides in lunar rocks have A) an isotope composition most similar to marine sulfate, which is enriched in 34S. B) an isotope composition most similar to marine mud, which is enriched in 34S. C) an isotope composition most similar to igneous rocks. D) exactly equal amounts of 34S and 32S.
C) an isotope composition most similar to igneous rocks.
3) The abundance of cyanobacterial mats has greatly declined due to the evolution of A) antimicrobial-producing fungi. B) bacteriophages. C) animal grazers. D) Proteobacteria.
C) animal grazers.
47) Another name for "programmed cell death" is A) necrosis. B) perforation. C) apoptosis. D) cellular degradation.
C) apoptosis.
59) The occurrence of multiple alleles at a specific locus is called A) signal transduction. B) the variable domain. C) polymorphism. D) allelic exclusion
C) polymorphism.
47) Nitrifying Thaumarchaeota can outcompete nitrifying bacteria in acidic environments because Thaumarchaeota A) are well-adapted to high salinity and extreme UV irradiation. B) are well-adapted to temperature extremes. C) are well-adapted to very low NH3 concentrations. D) have very resistant specialized cells that survive long periods of dehydration and nutrient starvation.
C) are well-adapted to very low NH3 concentrations.
68) Th17 cells produce IL-17, a cytokine responsible for A) neutralizing macrophages . B) developing macrophages . C) attracting neutrophils. D) neutralizing pathogens.
C) attracting neutrophils.
26) Two main symbionts of termites are ________ and ________. A) archaea / bacteria B) bacteria / fungi C) bacteria / protists D) fungi / protists
C) bacteria / protists
34) The pathogen-associated molecular pattern (PAMP) recognized by mannose-binding lectin (MBL) is the sugar mannose, found as a repeating subunit in A) human mucus. B) lymphocyte receptors. C) bacterial polysaccharides. D) bacterial proteins.
C) bacterial polysaccharides.
38) The microbial oxygen-consuming capacity of a water sample is called its A) chemical oxygen demand. B) biochemical capacity. C) biochemical oxygen demand. D) chemical capacity.
C) biochemical oxygen demand.
17) Well-designed microbial activity measurements can reveal ________ of major metabolic reactions in a habitat. A) types B) rates C) both types and rates D) either types or rates (but not both)
C) both types and rates
18) Pattern recognition receptors are most directly used A) by granulocytes to trigger degranulation. B) by neutrophils to detect self-tissues. C) by phagocytes to detect pathogens. D) by B cells to produce antibodies.
C) by phagocytes to detect pathogens.
24) The inflammatory cytokines IL-1, IL-6, and TNF-α are also A) opsonizing agents that coat foreign cells. B) responsible for decreasing vascular permeability. C) capable of producing systemic fever by stimulating the release of prostaglandins in the brain. D) part of the classical pathway of complement activation.
C) capable of producing systemic fever by stimulating the release of prostaglandins in the brain.
1) Primary endosymbioses gave rise to ________ and secondary endosymbioses gave rise to ________. A) chloroplasts in algae / chloroplasts in plants B) mitochondria in eukaryotes / chloroplasts in eukaryotes C) chloroplasts and mitochondria in plants and red and green algae / chloroplasts in other eukaryotes D) chloroplasts and mitochondria in green and red algae / chloroplasts and mitochondria in diatoms
C) chloroplasts and mitochondria in plants and red and green algae / chloroplasts in other eukaryotes
40) The cytoplasmic membrane of Thermoplasma contains a lipopolysaccharide-like material called lipoglycan that A) never contains sugars such as glucose. B) forms an unusual and flexible cell wall. C) contributes to membrane stability. D) may be present or absent dependent upon the temperature.
C) contributes to membrane stability.
32) Communication between cells of the immune system is accomplished in many cases through A) allelic exclusion. B) clonal deletion. C) cytokines. D) allelic exclusion, clonal deletion, and cytokines.
C) cytokines.
38) Compatible solutes counteract the tendency of a cell to become A) buoyant in high ionic strength environments. B) hyperosmotic in low ionic strength environments. C) dehydrated in high ionic strength environments. D) viscous in low ionic strength environments.
C) dehydrated in high ionic strength environments.
45) The structural and trophic foundation of coral reefs is a mutualistic relationship between A) cyanobacteria and sponges (Porifera). B) chemolithotrophic bacteria and stony corals (Cnidaria). C) dinoflagellates and stony corals (Cnidaria). D) cyanobacteria and stony corals (Cnidaria).
C) dinoflagellates and stony corals (Cnidaria).
5)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.
C) embedded in the agar, rather than growing on the surface.
27) The amoebozoa that are parasitic for humans are the A) gymnamoebas. B) radiolarians. C) entamoebas. D) oomycetes.
C) entamoebas.
5) Some of the largest, naturally occurring plasmids occur in the A) methanogens. B) Archaea lacking cell walls. C) extreme halophiles. D) genus Thermococcus.
C) extreme halophiles.
31) Metatranscriptomics and metaproteomics are favored over metagenomics when ________ is of more interest than ________. A) gene presence / phylogeny B) phylogeny / gene presence C) function or gene expression / gene presence D) gene presence / function or gene expression
C) function or gene expression / gene presence
13) The biggest limitation of traditional light microscopy and electron microscopy is that they are unable to reveal A) absolute cell concentration. B) cellular components of small microbes because of the limits of magnification. C) functional diversity of microorganisms in the habitat under study. D) physical microbial interactions as found in nature.
C) functional diversity of microorganisms in the habitat under study.
37) Extremely halophilic Archaea often form ________, probably in order to access ________. A) stalks / nutrients B) intracellular inclusions / elemental sulfur C) gas vesicles / oxygen D) intracellular membranes / sunlight
C) gas vesicles / oxygen
50) Culture-independent approaches avoid issues associated with A) detecting very rare phylotypes. B) conflating phylogenetic and functional diversity. C) growing organisms in the lab. D) next generation sequencing.
C) growing organisms in the lab.
39) The majority of basidiomycetes living in soil occur as A) diploid mycelia. B) diploid basidiocarps. C) haploid mycelia. D) haploid basidiocarps.
C) haploid mycelia.
4) Following antibiotic therapy, patients are often administered ________ to facilitate recolonization of normal microbiota in the intestines. A) fluoride B) iron C) probiotics D) antivirals
C) probiotics
44) The 13C/12C isotopic ratio of geological rocks of different ages has been used to examine whether previous biological activity occurred because compounds of biological origin A) do NOT contain 13C. B) have a higher proportion of 13C that compounds of geological origin. C) have a lower proportion of 13C that compounds of geological origin. D) are not well preserved in geological samples.
C) have a lower proportion of 13C that compounds of geological origin.
32) In contrast to bacterial endospores, fungal spores have substantially less resistance to A) chemicals. B) desiccation. C) heat. D) freezing.
C) heat.
40) In microbial ecology studies, the FISH technique identifies organisms based on A) the presence of green fluorescent protein. B) fluorescence of unique cofactors or pigments under certain wavelengths of UV light. C) hybridization of a fluorescent probe to specific ribosomal RNA sequences. D) the presence of luciferase.
C) hybridization of a fluorescent probe to specific ribosomal RNA sequences.
29) 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
C) hyphae / conidia
34) The purposeful artificial stimulation of active immunity to a particular infectious disease is known as A) immunodeficiency. B) hypersensitivity. C) immunization. D) opsonization.
C) immunization.
3)The term used when an organism is studied in its natural environment is A) au naturale. B) in vitro. C) in situ. D) in toto.
C) in situ.
28) Agricultural application of nitrogen fertilizer A) reduces global warming by increasing the storage of carbon dioxide in plant biomass. B) increases global warming by increasing microbial respiration in agricultural soils. C) increases global warming by increasing the production of nitrous oxide (N2O) by denitrification in agricultural soils. D) has little to no effect on the carbon cycle.
C) increases global warming by increasing the production of nitrous oxide (N2O) by denitrification in agricultural soils.
46) The most heavily colonized human organ by bacteria is the ________, containing 1011-1012 bacterial cells per gram. A) mouth B) small intestine C) large intestine D) skin
C) large intestine
49) Some intracellular pathogens produce phagocyte-killing proteins called ________ that kill the phagocyte after ingestion of the pathogen. A) antibodies B) antigens C) leukocidins D) pus
C) leukocidins
9) Retinal, in prokaryotes, is part of A) photosynthesis. B) phototaxis. C) light-driven ATP synthesis. D) chemotaxis.
C) light-driven ATP synthesis.
12) An example of a pathogen-associated molecular pattern (PAMP) is A) cell-surface proteins. B) flagellin proteins. C) lipopolysaccharide (LPS). D) pilus.
C) lipopolysaccharide (LPS).
15) A soil that lacks a dominant particle size is referred to as a(n) A) aggregation. B) bisequum. C) loam. D) mottled soil.
C) loam.
43) The green alga Botryococcus braunii is a candidate for production of biofuel due to its ability to produce A) and withstand large amounts of alcohols. B) hydrogen gas. C) long-chain (C30-C36) hydrocarbons. D) short-chain (C8-C14) hydrocarbons.
C) long-chain (C30-C36) hydrocarbons.
29) Bioremediation of uranium depends on A) fermentation and oxidation. B) methanogens. C) metal-reducing bacteria. D) sulfur-oxidizing bacteria.
C) metal-reducing bacteria.
38) Epithelial cells lining the respiratory tract form a A) dry and rigid barrier with tight junctions between cells. B) impenetrable barrier to infection. C) mucous membrane. D) connective tissue layer.
C) mucous membrane.
1) Two organisms that both benefit from each other are in a symbiotic relationship called A) ammensalism. B) commensalism. C) mutualism. D) parasitism.
C) mutualism.
1) 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.
C) of the pathogen to inflict damage on the host.
17) Enhanced phagocytosis of antibody-sensitized cells is known as A) complementation. B) immunization. C) opsonization. D) tolerance.
C) opsonization.
33) Sedimentation in bogs and marshes develops ________ soils. A) inorganic B) mineral C) organic D) loamy
C) organic
29) Siderophores are A) molecules that aid directly in attachment to host cells. B) inorganic molecules that help in active transport. C) organic molecules that help pathogens take up iron. D) toxins that affect the gastrointestinal tract.
C) organic molecules that help pathogens take up iron.
48) The human microbiome contains all A) organisms present on the skin. B) organisms within the digestive system. C) organisms present in and on the body. D) organisms present on the skin or in the digestive system only.
C) organisms present in and on the body.
20) Diatoms require silica due to their A) Ca2+/Si4+ symporters. B) DNA replication mechanism. C) ornate frustules. D) unique phototrophic physiology.
C) ornate frustules.
19) Bacterial oxidation of Fe2+ is commonly studied in chemolithotrophs that thrive under which specific environmental condition? A) Cold temperature B) High sunlight C) pH D) Nutrient replete
C) pH
43) Phagocytes have a pathogen-recognition system known as ________ that leads to the recognition, containment, and destruction of a pathogen. A) collagen B) fibrin C) pattern recognition receptors (PRR) D) pathogen-associated molecular pattern (PAMP)
C) pattern recognition receptors (PRR)
50) An endosymbiont of the rove beetle produces a chemical called ________ which deters predators. A) acetate B) pectin C) pederin D) paederus
C) pederin
9) Natural killer cells like Tc cells use ________ and granzymes to kill their targets without prior exposure or contact with the foreign cells. A) coagulants B) M protein C) perforin D) interferon gamma
C) perforin
18) The goal of wastewater treatment is to A) produce potable water. B) remove pathogens from wastewater before it is released. C) reduce organic and inorganic materials in wastewater to a level that no longer supports microbial growth. D) remove pathogens from wastewater to produce potable water.
C) reduce organic and inorganic materials in wastewater to a level that no longer supports microbial growth.
18) In insects, primary symbionts are ________, while secondary symbionts are ________. A) heritable / not heritable B) able to replicate outside of the host / obligate symbionts C) required for host reproduction / not required for host reproduction D) obligate symbionts / sometimes free-living
C) required for host reproduction / not required for host reproduction
7) Aerobic secondary treatment is usually best for ________ wastewater. A) industrial B) agricultural C) residential D) chemical
C) residential
52) The increased rate of O2 uptake by activated phagocytes is called the A) hypoxemia. B) pyogenesis. C) respiratory burst. D) peroxidase.
C) respiratory burst.
3) Most nitrogen-fixing bacteria symbiotically associated with plants are called A) bacteroids. B) mycorrhizae. C) rhizobia. D) symbiosome
C) rhizobia.
7) The specificity of certain rhizobia to infect only particular plants is in part due to the A) abundance of nutrients present in the soil. B) nifH genes they possess. C) rhizobial lipochitin oligosaccharides that act as signaling molecules. D) season (time of year).
C) rhizobial lipochitin oligosaccharides that act as signaling molecules.
40) The accessory pigment phycoerythrin is dominant in the ________ group of algae, which mostly lack flagella, have multicellular lifestyles, and occur in marine waters. Those in particular which deposit calcium carbonate in coral reef systems are classified as ________ algae. A) chlorophyte / coralline B) chlorophyte / rhodolithic C) rhodophyte / coralline D) rhodophyte / rhodolithic
C) rhodophyte / coralline
8) The mutualism of Azolla-Anabaena is useful for A) aquaculturists. B) corn farmers. C) rice farmers. D) tropical forest community succession.
C) rice farmers.
4) Plant root nodules are A) formed from gall-rotting bacteria that decompose plant roots. B) harmful to plants, because the bacteria outcompete the plants for nutrients. C) sites where nitrogen fixation occurs. D) structures created by fungi and are found in all agricultural crops.
C) sites where nitrogen fixation occurs.
42) Hot, sulfur-rich environments associated with terrestrial sulfur-rich springs are called A) acid-mine drainage. B) hydrothermal vents. C) solfataras. D) terrestrial volcanoes.
C) solfataras.
34) The proportion of Roseobacter species in the ocean describes A) species diversity. B) species richness. C) species abundance. D) species prevalence.
C) species abundance.
22) 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.
C) stem cells.
38) In the oceans, sulfur exists primarily as A) hydrogen sulfide (H2S). B) elemental sulfur (S0). C) sulfate (SO42-). D) gypsum (CaSO4).
C) sulfate (SO4)2-.
5) Some nitrifying prokaryotes carry out metabolic cooperation by a process known as A) competition. B) niche partitioning. C) syntrophy. D) antagonism.
C) syntrophy.
41) There is/are ________ different complementarity-determining regions in each V domain of an immunoglobulin (meaning ________ total in the V region). A) one / two B) two / four C) three / six D) four / eight
C) three / six
43) Clonal anergy is a state of A) antibody production. B) high energy. C) unresponsiveness. D) high energy and antibody production.
C) unresponsiveness.
42) Stable isotope probing (SIP) is a method that A) causes cells that hybridize with a fluorescent probe to fluoresce under UV light. B) compares the isotopic ratios of different compounds in the environment to determine whether they are of biological or geological origin. C) uses substrates containing heavy isotopes to label the DNA of organisms that use those substrates. D) compares the transcription of specific isotope labeled genes under different conditions.
C) uses substrates containing heavy isotopes to label the DNA of organisms that use those substrates.
15) Diatoms are A) found only in freshwater. B) more closely related to slime molds than to algae. C) usually morphologically symmetric. D) multicellular phototrophs.
C) usually morphologically symmetric.
40) The termite hindgut is A) entirely oxic. B) entirely anoxic. C) variable in oxygen concentration, with distinct microbial niches maintained by patterns of microbial oxygen consumption. D) entirely oxic or entirely anoxic depending upon the diet of the termite.
C) variable in oxygen concentration, with distinct microbial niches maintained by patterns of microbial oxygen consumption.
41) In the oceans, prokaryotes are greatly outnumbered by A) zooplankton. B) diatoms. C) viruses. D) phytoplankton.
C) viruses.
13) The vagina of an adult female is A) highly acidic. B) highly alkaline. C) weakly acidic. D) weakly alkaline.
C) weakly acidic.
33) The unusual ability of ________ being flagellated and motile enables ________. A) ascospores / their dispersal in aquatic systems B) ascospores / spreading of those pathogens in blood C) zoospores / dispersal in aquatic systems D) zoospores / spreading of those pathogens in blood
C) zoospores / dispersal in aquatic systems
4) Water leaving an efficient wastewater treatment facility ideally has a biochemical oxygen demand (BOD) between ________ units. A) 50 and 100 B) 25 and 50 C) 5 and 25 D) 0 and 5
D) 0 and 5
45) Assuming that each heavy and light chain has an equal chance to be expressed in each cell, approximately how many possible antibodies can be expressed? A) 192 B) 1,920 C) 19,200 D) 3,360,000
D) 3,360,000
13) Assuming exposure to the same climate, which of the following aquatic systems would be most stratified? A) 20 m deep freshwater river B) 50 m deep marine water fjord C) 200 m deep saltwater lake D) 300 m deep freshwater lake
D) 300 m deep freshwater lake
19) Which of the following is a probable life span of memory B cells? A) 5 minutes B) 5 hours C) 5 days D) 5 years
D) 5 years
27) What percentage of terrestrial plants are colonized by arbuscular mycorrhizae? A) 10-15% B) 25-30% C) 50-60% D) 70-90%
D) 70-90%
48) Approximately, ________% of all T cell precursors that enter the thymus do NOT survive the selection process. A) 15 B) 25 C) 45 D) 95
D) 95
20) Which of the following is a common feature of primary insect symbionts? A) Accelerated mutation rates only B) Extreme genome reduction only C) High A+T content only D) Accelerated mutation rates, extreme genome reduction, and high A+T content
D) Accelerated mutation rates, extreme genome reduction, and high A+T content
28) What is one reason that acetogenesis is favored over methanogenesis in the termite gut? A) The environment is anoxic. B) Methanogens can use a wide range of substrates, but acetogens specialize in those produced in the termite gut. C) Methanogens are not found in the termite gut. D) Acetogens are better at colonizing the center of the gut, which is rich in H2.
D) Acetogens are better at colonizing the center of the gut, which is rich in H2.
36) Which of the following processes does denitrification contribute to? A) Acid rain B) Ozone depletion C) Global warming D) Acid rain, ozone depletion, and global warming
D) Acid rain, ozone depletion, and global warming
39) Which of the following environmental and host factors influence the composition of the resident microbiota on the skin? A) Age B) Personal hygiene C) Weather D) Age, personal hygiene, and weather
D) Age, personal hygiene, and weather
31) Which of the following are proteins that interact directly with antigens during the adaptive immune response? A) Immunoglobulins B) Major histocompatibility complex C) T cell receptors (receptors on T cells) D) All of these
D) All of these
28) Which of the following does NOT affect pathogen growth? A) Availability of microbial nutrients B) pH C) Temperature D) All of these answer choices affect growth.
D) All of these answer choices affect growth.
25) Which of the following is a benefit of studying the human microbiome? A) It may allow for the development of personalized medical treatments. B) It may allow for more finely targeted probiotics. C) It may allow for increased recognition of disease biomarkers. D) All of these answer choices are possible benefits.
D) All of these answer choices are possible benefits.
50) The complete second signal for B cell activation requires which of the following interactions? A) Interleukin-4 release only B) Cytokine-cytokine receptor interaction only C) Th-B cell interaction only D) All of these are necessary
D) All of these are necessary
22) Which of the following does NOT influence immunogenicity? A) The routes of administration B) Foreign nature of the immunogen to the host C) Solubility D) All of these influence immunogenicity.
D) All of these influence immunogenicity.
13) Which statement is TRUE regarding fungal spores? A) Conidia and ascospores are sexual spores. B) Ascospores and basidiospores are asexual spores. C) Basidiospores and conidia are sexual spores. D) Ascospores and basidiospores are sexual spores.
D) Ascospores and basidiospores are sexual spores.
5) Which of the following is NOT a unifying characteristic of diplomonads and parabasalids? A) Having flagella B) Lacking chloroplasts C) Lacking mitochondria D) Being multicellular
D) Being multicellular
71) Dendritic cells (either activated or unactivated) act as antigen presenting cells for which of the following T cell subsets? A) Treg only B) Th17 only C) Neither Treg nor Th17 D) Both Treg and Th17
D) Both Treg and Th17
14) Which of the following are molecular mediators of inflammation? A) Immunoglobulins B) Lipopolysaccharide C) Erythrocytes D) Both chemokines and cytokines
D) Both chemokines and cytokines
42) Which of the following is a function of dendritic cells? A) Antigen presentation B) Plaque formation C) Phagocytosis D) Both phagocytosis and plaque formation
D) Both phagocytosis and plaque formation
26) Intracellular pathogens sometimes produce ________ that can kill phagocytes. A) lipopolysaccharides B) pathogen-associated molecular patterns (PAMPs) C) pattern recognition receptors (PRRs) D) leukocidins
D) leukocidins
39) What is the difference between adherence and colonization? A) Colonization occurs when transient microbes are on a tissue, whereas adherence is a more permanent attachment to cells. B) Colonization occurs when microbes begin to spread in host tissues, whereas adherence occurs when microbes initially attach. C) Colonization occurs when microbes begin to spread in host tissues, whereas adherence occurs when microbes first begin to reproduce in the host tissues. D) Colonization occurs when a microbe begins to grow in host tissues, whereas adherence occurs when the microbe initially attaches.
D) Colonization occurs when a microbe begins to grow in host tissues, whereas adherence occurs when the microbe initially attaches.
41) ________ in insects are intracellular bacteria that are usually localized to specialized organs within their host. A) Symbiodinium B) Arbuscules C) Epibionts D) Endosymbionts
D) Endosymbionts
51) Which of the following statements is FALSE concerning enrichment bias? A) Dilution of the inoculum may help to avoid enrichment bias in some cases. B) Enrichment bias is impossible to overcome in some oligotrophic environments. C) Enrichment bias resulted in the underestimation of prokaryotic diversity. D) Enrichment bias favors organisms that grow quickly.
D) Enrichment bias favors organisms that grow quickly.
38) Which of the following techniques can link prokaryotic phylogeny and metabolic function? A) DAPI staining B) Stable isotope probing only C) Environmental genomics only D) Environmental genomics and stable isotope probing
D) Environmental genomics and stable isotope probing
41) Which of the following are NOT phagocytes? A) Dendritic cells B) Monocytes C) Neutrophils D) Erythrocytes
D) Erythrocytes
10) Which of the following enzymes are NOT secreted by Th1 cells to activate macrophages? A) Granulocyte-monocyte colony stimulating factor B) Interferon gamma C) TNF-α D) Fibrin
D) Fibrin
19) What technique(s) can be used to characterize the phylogenetic composition of a microbial community without culturing any of the members? A) Green fluorescent protein tagging B) Stable isotope techniques C) Radioisotope experiments D) Fluorescent in situ hybridization (FISH)
D) Fluorescent in situ hybridization (FISH)
23) Which molecular method allows for the detection of a specific organism within a diverse microbial community? A) Fluorescent DNA staining using DAPI B) Viability staining C) Enrichment techniques D) Fluorescent in situ hybridization (FISH)
D) Fluorescent in situ hybridization (FISH)
52) Which of the following is secreted by Th1 cells to stimulate macrophage differentiation and activation? A) Granulocyte-monocyte colony stimulating factor only B) Interferon gamma only C) Tumor necrosis factor-alpha only D) Granulocyte-monocyte colony stimulating factor, interferon gamma, and tumor necrosis factor-alpha
D) Granulocyte-monocyte colony stimulating factor, interferon gamma, and tumor necrosis factor-alpha
13) Which of the following is a sulfide? A) H2S B) HS- C) S2- D) H2S, HS-, and S2- are all sulfides.
D) H2S, HS-, and S2- are all sulfides.
38) Which of the following is/are MHC class I genes? A) HLA-A B) HLA-B C) HLA-C D) HLA-A, HLA-B, and HLA-C
D) HLA-A, HLA-B, and HLA-C
27) What reaction is catalyzed by mercuric reductase? A) Hg(CH3)2 to Hg2+ B) CH3Hg+ to Hg2+ C) Hg4+ to Hg2+ D) Hg2+ to Hg0
D) Hg2+ to Hg0
45) Which of the following is NOT a major question in the Human Microbiome Project? A) Are differences in the relative abundance of different bacteria important? B) Do differences in the human microbiome correlate with differences in human health? C) Is there a correlation between microbial population structure and host genotype? D) How can we reduce the number of microbes on the human body?
D) How can we reduce the number of microbes on the human body?
44) Which of the following contribute to the limitless diversity generated from a relatively fixed number of immunoglobulin genes? A) Hypermutation only B) Random heavy and light chain reassortment only C) Somatic recombination only D) Hypermutation, random heavy and light chain reassortment, and somatic recombination
D) Hypermutation, random heavy and light chain reassortment, and somatic recombination
13) The most common circulating antibody, comprising about 80% of the serum immunoglobulin, is A) IgA. B) IgC. C) IgD. D) IgG.
D) IgG.
33) Which of the following is a common benefit of a microbe-plant symbiosis? A) Increased nutrient availability only B) Decreased pathogen colonization only C) Increased affinity for carbon dioxide D) Increased nutrient availability and decreased pathogen colonization
D) Increased nutrient availability and decreased pathogen colonization
28) What adaptation allows organisms to tolerate high pressures? A) Decreased cell size B) Decreased lipid content C) Increased ribosome size D) Increased unsaturated fatty acids
D) Increased unsaturated fatty acids
32) Based on your knowledge of hydrocarbon degradation, what is one factor that most likely limited the rate of petroleum degradation after the Exxon Valdez oil spill off the coast of Alaska? A) Salt concentration B) Chemical dispersants C) O2 concentration D) Inorganic nutrient concentrations
D) Inorganic nutrient concentrations
16) Which iron species is produced primarily from iron smelting and rarely is produced by microbial-mediated processes? A) Ferric iron (Fe3+) B) Ferrous iron (Fe2+) C) Ferulic iron (Fe1+) D) Iron (Fe0)
D) Iron (Fe0)
26) The amoebozoa use what structures for movement and feeding? A) Threadlike pseudopodia B) Cilia C) Flagella D) Lobe-shaped pseudopodia
D) Lobe-shaped pseudopodia
8) The secondary lymphoid organs consist of which of the following? A) Lymph nodes only B) Mucosal-associated lymphoid tissue (MALT) only C) The spleen only D) Lymph nodes, MALT, and the spleen
D) Lymph nodes, MALT, and the spleen
2) Which of the following is NOT a subunit of lipopolysaccharide (LPS)? A) O-specific polysaccharide B) Lipid A C) Core polysaccharide D) M protein
D) M protein
28) Pattern recognition receptors (PRRs) are found on which of the following cells? A) Macrophages B) Bacteria C) Neutrophils D) Macrophages and neutrophils
D) Macrophages and neutrophils
59) Why do gut fungi, Neocallimastix, possess a hydrogenosome instead of mitochondria? A) Neocallimastix needs hydrogenosome for the degradation of lactic acid and VFAs. B) Neocallimastix contains hydrogenosome because it is a flagellated fungus. C) Neocallimastix requires hydrogenosome for motility. D) Neocallimastix contains hydrogenosome as an adaptation to anaerobic environment.
D) Neocallimastix contains hydrogenosome as an adaptation to anaerobic environment.
3) Which statement best describes our current understanding of the eukaryotic phylogenetic tree? A) Ribosomal RNA data allowed the development of the current phylogeny with six supergroups. B) Whole genome data was used to distinguish the three domains. C) The most recent analyses have conclusively shown the relationships of the six supergroups. D) New discoveries will probably lead to changes in the eukaryotic phylogenetic tree.
D) New discoveries will probably lead to changes in the eukaryotic phylogenetic tree.
12) Compared with an endotoxin, would a bacterial exotoxin generally be more likely to function after it had been significantly heated? A) Yes, because exotoxins are very heat stable compared to endotoxins. B) Yes, because exotoxins are proteins and nonliving but endotoxins are part of the bacterial cell wall. C) No, because exotoxins are carbohydrates and endotoxins are proteins. D) No, because exotoxins are heat-labile and less resistant to heating than endotoxins.
D) No, because exotoxins are heat-labile and less resistant to heating than endotoxins.
35) A mutant of Rhizobium leguminosarum is able to survive and reproduce in the laboratory outside of plant roots, but can no longer initiate root nodule formation. What type of genes are most likely mutated in this mutant? A) Rhz genes B) Myc genes C) Nif genes D) Nod genes
D) Nod genes
70) Which of the following T cell subsets is a CD8 T cell? A) Treg B) Th17 C) Th2 D) None of these
D) None of these
10) Which group of eukaryotes LACKS alveoli? A) Apicomplexans B) Ciliates C) Dinoflagellates D) Oomycetes
D) Oomycetes
18) Which aquatic habitat contains a pelagic zone? A) Estuary B) Lake C) Salt marsh D) Open ocean
D) Open ocean
31) Which of the following can be completely degraded to carbon dioxide by microorganisms? A) Inorganic pollutants B) Uranium C) Xenobiotics D) Petroleum
D) Petroleum
3) Which organisms form the foundation of the carbon cycle? A) Anaerobic chemolithotrophs B) Chemoheterotrophs C) Chemoorganotrophs D) Phototrophs
D) Phototrophs
9) Which of the following can cause allergy symptoms and inflammation by degranulation? A) Dendritic cells B) Erythrocytes C) Macrophages D) Polymorphonuclear leukocytes
D) Polymorphonuclear leukocytes
32) Which statement exemplifies the biological pump concept? A) Autotrophs bring in light photons to synthesize ATP. B) Bacteria oxidize Fe2+ into Fe3+, and Archaea reduce Fe3+ back into Fe2+. C) Calcium ions are brought into cells while toxic physiological by-products are released. D) Primary producers sink to the deep ocean, which provides deep ocean organisms with nutrients when the primary producers die.
D) Primary producers sink to the deep ocean, which provides deep ocean organisms with nutrients when the primary producers die.
28) Based upon microbiome projects, the most dominant microbial species in sebaceous gland system is A) Corynebacterium species. B) Streptococcus species. C) Staphylococcus species. D) Propionibacterium species.
D) Propionibacterium species.
45) ________ is the phylogenetic group most abundant in terrestrial soils. A) Bacteroidetes B) Acidobacteria C) Firmicutes D) Proteobacteria
D) Proteobacteria
9) Which of the following are NOT found in the gastrointestinal tract of healthy humans? A) Bacteroides B) Clostridium C) Escherichia coli D) Protists
D) Protists
4) A notorious biofilm former implicated in cystic fibrosis is A) Bacillus subtilis. B) Escherichia coli. C) Lactobacillus acidophilus. D) Pseudomonas aeruginosa.
D) Pseudomonas aeruginosa.
34) Spoilage of bread, which appears dark green-blue to black in color, is most likely caused by the fungus A) Aspergillus niger. B) Batrachochytrium dendrobatidis. C) Glomus spp. D) Rhizopus nigricans.
D) Rhizopus nigricans.
21) What is a characteristic of a deep sea marine cold seep/vent? A) Acidic B) Luminous C) Low pressure D) Rich in methane
D) Rich in methane
Which is not a protist? A) Amoeba B) Euglena C) Giardia D) Saccharomyces
D) Saccharomyces
11) Which metabolic strategy is most common in chemolithotrophic mats? A) Ammonia oxidation B) Iron oxidation C) Nitrate reduction D) Sulfur oxidation
D) Sulfur oxidation
1) T cells recognize antigens with their A) antibodies. B) leukocidins. C) M proteins. D) T cell receptors.
D) T cell receptors.
10) Which of the following methods do NOT involve nucleic acid hybridization of a probe to a specimen? A) RACE-FISH B) FISH-MAR C) PhyloChips D) T-RFLP
D) T-RFLP
25) In deep pelagic waters, the archaeal species present are almost all members of A) Crenarchaeota. B) Euryarchaeota. C) Nanoarchaeota. D) Thaumarchaeota.
D) Thaumarchaeota.
38) How does the diversity of bacteria and fungi differ between outdoor and indoor environments? A) While the species differ, the diversity is similar. B) There is a greater diversity outdoors than indoors. C) It depends on the local geography. D) There is a greater diversity indoors than outdoors.
D) There is a greater diversity indoors than outdoors.
18) A chemoorganotroph growing optimally at 55°C and pH2 in complex media would most likely be a member of the genus A) Methanocaldococcus. B) Halobacterium. C) Methanococcus. D) Thermoplasma
D) Thermoplasma
6) Which of the following is TRUE about cytokines? A) They are carbohydrates. B) They play an important role in immunity, but do not affect stem cell growth. C) They play a role in the growth of stem cells, but are not important in immunity. D) They are proteins that play an important role in immunity and the growth of stem cells.
D) They are proteins that play an important role in immunity and the growth of stem cells.
35) Which of the following is TRUE about flagella? A) They are the most important structure in adherence. B) They are not involved in adherence and colonization at all. C) They are as important in adherence as pili and fimbriae. D) They may be involved in adherence to a lesser extent than pili and fimbriae.
D) They may be involved in adherence to a lesser extent than pili and fimbriae.
10) What is the role of the vir genes on a Ti plasmid? A) To cause crown gall disease (virulence) B) To confer resistance to viral infection C) To initiate replication of the plasmid D) To allow T-DNA transfer
D) To allow T-DNA transfer
24) For what purpose would a microbial ecologist use a microsensor? A) To determine the concentration of cells in small increments in a sediment or water column B) To determine the expression of a particular gene in a microbial community C) To quantify the uptake of a radioactive material D) To determine the concentration of O2, N2O, or other chemical species in small increments in a sediment or water column
D) To determine the concentration of O2, N2O, or other chemical species in small increments in a sediment or water column
30) Why do obligate symbionts often contain lower G+C content when compared to free-living organisms? A) Ancestral symbionts had low G+C content genomes by chance, and these low G+C content genomes are passed onto their progeny. B) Organisms with a low G+C content organisms are at a selective disadvantage to those with a high G+C content when free-living. C) It is more difficult to replicate high G+C content genomes than to replicate low G+C content genomes. D) Two common spontaneous mutations change GC pairs into AT pairs and symbionts usually have fewer DNA repair mechanisms to fix these compared with free-living organisms.
D) Two common spontaneous mutations change GC pairs into AT pairs and symbionts usually have fewer DNA repair mechanisms to fix these compared with free-living organisms.
46) Somatic hypermutation occurs only in the ________ regions of rearranged heavy and light chains. A) D B) HV C) J D) V
D) V
2) The insect symbiont Wolbachia can be used to suppress disease transmission by mosquitoes because A) Wolbachia supplies essential nutrients to the mosquito Culex quinquefasciatus. B) only Wolbachia-infected mosquitoes can transmit viral diseases such as dengue fever. C) Wolbachia infections can spread rapidly through a mosquito population, killing all the mosquitoes. D) Wolbachia-infected male mosquitoes sterilize uninfected female mosquitoes.
D) Wolbachia-infected male mosquitoes sterilize uninfected female mosquitoes.
24) The host-microbiome supraorganism refers to A) the human body and all of the microbes found within it, but not those on the external surfaces. B) a nonhuman animal and all of the microbes found within it, but not those on the external surfaces. C) a human body and all of its commensal microbes. D) a body and all of its associated microbes.
D) a body and all of its associated microbes.
21) Use of antibiotics in newborns can cause all of the following EXCEPT A) an autoimmune disorder IBD B) an obesity C) a disruption of normal gut microbiota D) a decreased abundance of Clostridium difficile
D) a decreased abundance of Clostridium difficile
36) Robotic systems used to quickly test the response of microbes in microtiter plates to thousands of combinations of nutrients is an example of ________ technology. A) a next generation sequencing B) a stable isotope C) a genomic D) a high-throughput
D) a high-throughput
7)The term axenic is used to describe A) an anaerobic culture. B) an anoxygenic culture. C) a nutritionally deficient culture. D) a pure culture.
D) a pure culture.
30) The ocean has mitigated the impact of anthropogenic carbon dioxide production by A) absorbing 500 billion tons of atmospheric carbon dioxide. B) absorbing over 80% of the trapped heat energy. C) storing 600 billion tons of organic carbon. D) absorbing 500 billion tons of atmospheric carbon dioxide and over 80% of the trapped heat energy.
D) absorbing 500 billion tons of atmospheric carbon dioxide and over 80% of the trapped heat energy.
43) Increasing atmospheric carbon dioxide is A) increasing sedimentation of C, Ca, and Si. B) increasing the effect of the biological pump. C) fueling increased primary production in ocean waters. D) acidifying the ocean and decreasing the rate of formation of calcareous shells.
D) acidifying the ocean and decreasing the rate of formation of calcareous shells.
17) Frankia are A) a type of arbuscular mycorrhizae. B) glomeromycetes that live in root nodules. C) a species of tree that has root nodules. D) actinomycetes that fix nitrogen.
D) actinomycetes that fix nitrogen.
45) Nitrogen fixation results in the A) loss of biologically available N from an ecosystem. B) formation of nitrogen gas. C) direct formation of nitrate. D) addition of biologically available N to an ecosystem.
D) addition of biologically available N to an ecosystem.
13) The rumen is an ________ habitat that depends on ________ to digest cellulose for ruminant animals. A) aerobic / cellulolytic fungi B) aerobic / cellulolytic and fermentative bacteria C) anaerobic / methanogens D) anaerobic / cellulolytic and fermentative bacteria
D) anaerobic / cellulolytic and fermentative bacteria
4) Intrinsic properties of immunogens include A) appropriate physical form only. B) molecular size only. C) sufficient molecular complexity only. D) appropriate physical form, molecular size, and molecular complexity.
D) appropriate physical form, molecular size, and molecular complexity.
30) Cytolytic toxins A) are extracellular proteins. B) cause cell lysis and death. C) damage host cytoplasmic membrane. D) are extracellular proteins that cause cell lysis and death by damaging the host cytoplasmic membrane.
D) are extracellular proteins that cause cell lysis and death by damaging the host cytoplasmic membrane.
35) Lignin is a complex polymer of methoxylated ________ compounds and is present in ________. A) silica / aquatic environments B) mineral / rocks C) oil / fossil fuels D) aromatic / vascular plant material
D) aromatic / vascular plant material
30) The child gut microbiota resembles the adult microbiota A) by 12 months of age. B) by 1 month of age. C) around age 15. D) around age 3.
D) around age 3.
33) Chemokines are a group of small proteins that A) attract T cells to sites of injury. B) function as chemoattractants for phagocytes and lymphocytes. C) potentiate specific immune responses. D) attract T cells, phagocytes, and lymphocytes, as well as potentiate specific immune responses.
D) attract T cells, phagocytes, and lymphocytes, as well as potentiate specific immune responses.
19) Water distribution systems contain A) very few bacteria or other microorganisms. B) no microbial growth substrates. C) sediment and flocs. D) biofilms that may harbor opportunistic pathogens.
D) biofilms that may harbor opportunistic pathogens.
40) The primary function of a phagocyte is to A) destroy pathogens. B) engulf pathogens. C) evade pathogens. D) both engulf and destroy pathogens.
D) both engulf and destroy pathogens.
16) Dimers of IgA are present in A) breastmilk colostrum. B) saliva. C) tears. D) breastmilk colostrum, saliva, and tears.
D) breastmilk colostrum, saliva, and tears.
43) The element(s) that have proven most useful for stable isotope studies are A) carbon only. B) nitrogen only. C) sulfur only. D) carbon, sulfur, and sometimes nitrogen.
D) carbon, sulfur, and sometimes nitrogen.
2) The pouch at the beginning of the large intestine is called the A) cardia. B) ileum. C) colon. D) cecum.
D) cecum.
42) In a freshwater pond, a green alga is likely to be A) only colonial. B) only filamentous. C) only unicellular. D) colonial, filamentous, multicellular, or unicellular.
D) colonial, filamentous, multicellular, or unicellular.
39) Sulfide is toxic to respiring organisms because it can combine with metals present in ________ that serve a critical function in respiration. A) glycolysis enzymes B) oxidases C) NADH D) cytochromes
D) cytochromes
5) The damaged areas of teeth caused by organic acids produced by dental plaque are called A) degenerative plaque. B) calcified plaque. C) periodontal disease. D) dental caries.
D) dental caries.
35) Obligate symbiotic fungi that form associations with plants by entering their cortical cells without invading the plant cell's membrane are called ________ and include the genus ________. A) ectomycorrhizae / Agaricus B) ectomycorrhizae / Glomus C) endomycorrhizae / Agaricus D) endomycorrhizae / Glomus
D) endomycorrhizae / Glomus
2)The methodology of microbial ecology includes A) enrichment and isolation of specific microbes. B) cell-staining methods. C) gene, transcript, and protein characterization. D) enrichment and isolation of specific microbes, cell-staining, and characterization of genes, transcripts, and proteins.
D) enrichment and isolation of specific microbes, cell-staining, and characterization of genes, transcripts, and proteins.
35) The human gastrointestinal tract includes all of the following EXCEPT the A) small intestine. B) stomach. C) large intestine. D) epiglottis.
D) epiglottis.
46) Bacterial symbionts most often provide marine invertebrates in hydrothermal vents with A) fixed nitrogen in the form of ammonia. B) sulfate and other sulfur compounds. C) cellulolytic enzymes to help digest plant material. D) fixed carbon dioxide in the form of organic compounds.
D) fixed carbon dioxide in the form of organic compounds.
25) Microarrays are useful for assessing A) gene expression only. B) enzyme activity. C) the presence of specific rRNA sequences only. D) gene expression and the presence of specific rRNA sequences.
D) gene expression and the presence of specific rRNA sequences.
44) The macromolecules responsible for bacterial adherence that are NOT covalently attached to bacteria are collectively called A) lipid A. B) biofilms. C) capsules. D) glycocalyx.
D) glycocalyx.
19) Horizontal gene transfer between insects and their symbionts A) happens frequently because of coevolution. B) causes genome reduction in the symbiont and genome expansion in the host. C) causes genome reduction in both the host and the symbiont. D) has been observed, but is considered a rare event.
D) has been observed, but is considered a rare event.
35) Genomic analysis of Prochlorococcus has revealed A) the presence of bacteriorhodopsin. B) that no regions are shared between cultured representatives and environmental populations. C) complete congruence of genes and genome structure within the same phylotype. D) high levels of gene conservation between cultured representatives and environmental populations.
D) high levels of gene conservation between cultured representatives and environmental populations.
1)The science of microbial ecology deals with A) how microbial communities interact with each other and their environment. B) microbial activity and biodiversity C) microbial gene regulation mechanisms in response to environmental change. D) how the activity and biodiversity of microbial communities affect microbial interactions with each other and the environment
D) how the activity and biodiversity of microbial communities affect microbial interactions with each other and the environment
44) Oxygen compounds toxic to pathogens include A) hydrogen peroxide. B) hypochlorous acid. C) nitric oxide. D) hydrogen peroxide, hypochlorous acid, and nitric oxide.
D) hydrogen peroxide, hypochlorous acid, and nitric oxide.
21) The goal of tertiary wastewater treatment is to sharply reduce the levels of ________ from the final effluent. A) organic compounds B) heavy metals C) methane D) inorganic nutrients
D) inorganic nutrients
39) Secondary symbionts in insects often live A) inside cells only. B) in hemolymph only. C) inside bacteriocytes only. D) inside cells, in hemolymph, or inside bacteriocytes
D) inside cells, in hemolymph, or inside bacteriocytes
55) Bacterial defensive symbionts of insects can be located A) only inside the cells. B) only within the gut. C) both within the gut and inside the cells. D) inside the cells, within the gut and on the exoskeleton.
D) inside the cells, within the gut and on the exoskeleton.
5) Decalcification of the tooth enamel is caused by A) lipopolysaccharide. B) dextrans. C) formic acid. D) lactic acid.
D) lactic acid.
7) Some strains of haloarchaea exhibit A) anoxic growth at the expense of sugar fermentation. B) anaerobic respiration. C) anoxygenic photosynthesis. D) light-driven ATP synthesis under oxygen-limiting conditions.
D) light-driven ATP synthesis under oxygen-limiting conditions.
55) The chemokine CCL2 is produced by A) Th2 cells. B) dendritic cells. C) basophils. D) macrophages.
D) macrophages.
4) Frozen methane molecules are called A) anhydrous methane. B) anoxic methane. C) methane anhydrates. D) methane hydrates.
D) methane hydrates.
11) Antibodies are found in A) milk. B) mucosal secretions. C) serum. D) milk, mucosal secretions, and serum.
D) milk, mucosal secretions, and serum.
13) 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.
D) neutralization.
39) To prevent the souring of crude oil, ________ is added to oil well injection water to encourage ________ instead of ________. A) oxygen / aerobic respiration / sulfate reduction B) sulfate / sulfate reduction / fermentation C) sulfate / sulfate reduction / nitrate reduction D) nitrate / nitrate reduction / sulfate reduction
D) nitrate / nitrate reduction / sulfate reduction
6) Giardia are diplomonads which have nuclei that A) appear as two separate chromosomes but are weakly joined. B) contain one small and one large nucleus per cell. C) have one nucleus enclosed in a mitosome and another nucleus in their cytoplasm. D) occur as two similar sizes per cell.
D) occur as two similar sizes per cell.
16) MHC I proteins are found A) on B cells only. B) on macrophages only. C) on dendritic cells only. D) on all nucleated cells.
D) on all nucleated cells.
27) C-reactive protein is a A) pathogen-associated molecular pattern (PAMP). B) homotrimeric adaptor protein. C) lipoprotein. D) pattern recognition receptor (PRR).
D) pattern recognition receptor (PRR).
36) Interaction of a pathogen-associated molecular pattern (PAMP) with a toll-like receptor (TLR) triggers transmembrane signal transduction and subsequent A) clonal expansion. B) antibody production. C) complement protein activation. D) phagocytosis and inflammation.
D) phagocytosis and inflammation.
43) Cells within a biofilm excrete an adhesive matrix primarily composed of ________ but can also contain nucleic acids as well as proteins. A) lipids B) fatty acids C) monomers D) polysaccharides
D) polysaccharides
46) Nitrous oxide (N2O) is a A) direct product of ammonification. B) direct product of nitrogen fixation. C) potent greenhouse gas that is a product of nitrification. D) potent greenhouse gas that is a product of denitrification.
D) potent greenhouse gas that is a product of denitrification.
51) Insect symbionts can benefit the host by A) protecting it from microbial pathogens and obtaining nutrients such as arabinose. B) protecting it from predation, microbial pathogens and obtaining uncommon hydroquinone. C) protecting it from parasitism, microbial pathogens, predation and obtaining raffinose. D) protecting it from predation, microbial pathogens and parasitism.
D) protecting it from predation, microbial pathogens and parasitism.
9) Exotoxins are ________, but endotoxins are ________. A) lipopolysaccharide-lipoprotein complexes / proteins B) carbohydrates / proteins C) lipids / proteins D) proteins / lipopolysaccharide-lipoprotein complexes
D) proteins / lipopolysaccharide-lipoprotein complexes
8) The metabolic process of denitrification A) oxidizes N2. B) oxidizes NO3-. C) reduces N2. D) reduces NO3-.
D) reduces NO3-.
44) The topoisomerase called ________ introduces positive supercoils in DNA, which stabilizes DNA and prevents the DNA helix from denaturing at high temperatures. A) reverse ligase B) ligase C) DNA gyrase D) reverse DNA gyrase
D) reverse DNA gyrase
2) Evidence of ________ supports the hypothesis that eukaryotes are derived from bacteria. A) antibiotic resistance B) DNA content in the nucleus only C) ribosome characteristics only D) ribosome characteristics and DNA content in the nucleus
D) ribosome characteristics and DNA content in the nucleus
41) The overall purpose of DGGE is to A) separate genes that differ in length. B) measure the activity of cells that use DGGE as an energy source. C) detect cells that utilize a specific radiolabeled substrate. D) separate genes of the same length that have different sequences, resulting in different denaturation profiles.
D) separate genes of the same length that have different sequences, resulting in different denaturation profiles.
24) The spread of pathogens through the blood and lymph systems that results in a bloodborne systemic infection is called A) bacteremia. B) cancer. C) pathogenesis. D) septicemia.
D) septicemia.
46) It is difficult to estimate when cyanobacteria appeared on Earth using the evidence from the oxidation state of the Earth's crust because A) several ancient anaerobic metabolisms require O2. B) there are multiple forms of anoxygenic photosynthesis. C) there are multiple groups of oxygenic photosynthetic bacteria. D) several ancient anaerobic metabolisms form Fe3+ without requiring O2.
D) several ancient anaerobic metabolisms form Fe3+ without requiring O2.
39) An individual usually expresses ________ structurally distinct allele(s) that encode class I MHC proteins. A) one B) two C) four D) six
D) six
6) The generation time of Escherichia coli in the human intestine is ________ in laboratory culture. A) at about the same rate as B) faster than C) more optimal than D) slower than
D) slower than
31) Cellular integrity and cell wall stabilization of the Halobacterium are aided by A) potassium ions. B) chloride ions. C) magnesium ions. D) sodium ions.
D) sodium ions.
25) Mercury is commonly found in A) some electronics, but not in pesticides. B) some compounds that are neurotoxins, but not in electronics. C) some pesticides, but not in any neurotoxins. D) some electronics, some pesticides, and some neurotoxic compounds.
D) some electronics, some pesticides, and some neurotoxic compounds.
17) Antigen exposure is necessary to A) induce genetic hypermutation in B cells with productive antibody genes. B) stimulate B cells to differentiate into plasma cells. C) stimulate B cells to produce soluble antibodies. D) stimulate B cell differentiation, antibody production, and genetic hypermutation of antibody genes.
D) stimulate B cell differentiation, antibody production, and genetic hypermutation of antibody genes.
30) Pure cultures can be obtained from an enrichment culture using A) streak plates only. B) the agar dilution method only. C) liquid dilution methods only. D) streak plates, the agar dilution method, or liquid dilution methods.
D) streak plates, the agar dilution method, or liquid dilution methods.
54) Methane oxidation is a bacterial metabolic process during which the methane is oxidized with terminal electron acceptors such as A) sulfate, nitrate, and oxygen. B) tetrachloroethylene and dichloroethene. C) sulfate and oxygen. D) sulfate, nitrate, and ferric iron.
D) sulfate, nitrate, and ferric iron.
12) The burning of fossil fuels produces significant amounts of A) sulfate. B) sulfite. C) sulfonate. D) sulfur dioxide.
D) sulfur dioxide.
5) A process where different microbial taxa work in cooperation to degrade a compound that neither can degrade entirely on their own is called A) allotropy. B) amensalism. C) commensalism. D) syntrophy.
D) syntrophy.
3) Adaptive immunity occurs when A) death results from pathogen infection. B) the innate immune response is overly effective. C) a broad, rapid response is needed to a wide range of pathogens from the body regardless of the specific type of pathogen. D) the innate immune response fails to eliminate pathogens in the body and virulent infections persist after the initial innate defense response.
D) the innate immune response fails to eliminate pathogens in the body and virulent infections persist after the initial innate defense response.
9) In the soil, oxygen concentrations are highly variable even within a soil particle. The center of the particle may be anoxic even if the outer portions are oxygen rich. In this context, facultative anaerobes could be found A) at the surface of the particle. B) in the center of the particle. C) in the middle regions of the particle. D) throughout the particle.
D) throughout the particle.
49) Single-cell genomics may help us A) predict which microbes will be abundant based on the environmental conditions. B) understand the physiology of uncultured microbes. C) develop better enrichment culture methods. D) understand the physiology of uncultured microbes and develop better enrichment culture methods.
D) understand the physiology of uncultured microbes and develop better enrichment culture methods.
18) Radioisotopes are useful when A) very high sensitivity is required. B) turnover rates need to be determined. C) the fate of portions of particular molecules need to be followed. D) very high sensitivity is required, turnover rates need to be determined, and the fate of portions of particular molecules need to be followed.
D) very high sensitivity is required, turnover rates need to be determined, and the fate of portions of particular molecules need to be followed.
58) The ________ and ________ domains of the class II MHC protein interact to form a peptide-binding site. A) B / T B) light / heavy C) C / V D) α1 / β1
D) α1 / β1
