Microbiology - Exam 2 + 3 + 4 Study Guide
Hemolytic disease of the newborn can result from an Rh+ mother with an Rh- fetus. Rh- mother with an Rh+ fetus. Rh- mother and an A fetus. AB mother with a B fetus. AB mother with an O fetus.
Rh- mother with an Rh+ fetus.
Humans are the definitive host for __________, which is a type of __________. Echinococcus granulosus; tapeworm Taenia solium; roundworm Plasmodium; cestode Taenia saginata; tapeworm
Taenia saginata; tapeworm
What part of the nervous system is most affected by fatal familial insomnia? Cerebellum The spinal cord Cerebrum Thalamus
Thalamus
Agar is used as a solidifying agent in microbiological media since few bacteria can degrade it. True False
True
Agglutination tests use particulate antigens while precipitation tests use soluble antigens. True False
True
An isolated colony on a streak plate contains millions or billions of identical cells. True False
True
Antiviral drugs target viral processes that occur during viral infection. True False
True
Arthropod vectors are blood-sucking animals such as ticks, lice, and fleas that transmit microbial pathogens. True False
True
Aspirin alleviates pain, inflammation, and fever by inhibiting prostaglandins. True False
True
Autoclaving is the most effective method of moist heat sterilization. True False
True
Bacterial growth refers to an increase in the numbers of cells in a bacterial culture. True False
True
Both the cellular slime molds and the plasmodial slime molds are members of the phylum Amoebozoa. True False
True
Cancer is similar to an infectious disease in that it is due to a failure of the bodys defenses. True False
True
Cercariae, metacercaria, redia, and sporocysts are all life cycle stages of trematodes. True False
True
Currently, no members of Archaea have been linked to human disease. True False
True
Histamine and kinins cause increased blood flow and capillary permeability. True False
True
Moist heat destroys organisms by denaturing proteins. True False
True
Mutations that are harmful to cells occur more frequently than those that benefit cells. True False
True
Recombination will always alter a cells genotype. True False
True
Some antimicrobial chemicals are considered to be disinfectants and antiseptics. True False
True
Some species of dinoflagellates produce neurotoxins that cause fish kills and red tides. True False
True
The basic mechanism of viral multiplication is similar for all viruses. True False
True
The home pregnancy test kit is an example of a direct ELISA. True False
True
The thermal death time is the time needed to kill all the bacteria in a particular culture at a certain temperature. True False
True
Turbidity is an indirect measurement of bacterial growth that can be measured using a spectrophotometer. True False
True
Vaccines are preparations of organisms or fractions of organisms that are used to induce protective immune responses. True False
True
Western blotting uses antibodies to detect specific proteins in a mixture of proteins. True False
True
The following events occur if human cells expressing HLA-I are mixed with anti-HLA-I, complement, and trypan blue. What step indicates the cells are HLA-I? Enzyme is released from neutrophils. Cells are damaged by complement. Anti-HLA antibodies bind to HLAs on lymphocytes. Trypan blue enters the cells. None of the answers are correct; the T cells are missing.
Trypan blue enters the cells.
Which of the following microorganisms actually grows inside the macrophage? Tuberculosis bacterium Streptococcus pneumoniae Shigella Leishmania Legionella
Tuberculosis bacterium
Starting with three cells, how many cells would result from three rounds of replication? Six Nine Twelve Twenty-four Forty-eight Cannot be determined
Twenty-four
How many answers are there to a question in a dichotomous key flowchart? Two Four Any number of answers are possible. Three
Two
Which of the following does NOT constitute an advantage of using two antibiotics together? It allows treatment to be provided prior to diagnosis. It can prevent drug resistance. It lessens the toxicity of individual drugs. Two are always twice as effective as one. All of these are advantages of using two antibiotics together.
Two are always twice as effective as one.
What are the products of semiconservative replication for a double-stranded DNA molecule? Two double-stranded DNA molecules, each consisting of one parental strand and one daughter strand. One double-stranded DNA molecule, consisting of two daughter strands. Two double-stranded DNA molecules, one consisting of two parental strands and the other consisting of two daughter strands. One double-stranded DNA molecule consisting of one parental strand and one daughter strand.
Two double-stranded DNA molecules, each consisting of one parental strand and one daughter strand.
What results when a single bacterium reproduces? Two genetically unique daughter cells One parent cell and a genetically identical daughter cell One parent cell and a genetically different cell Two genetically identical daughter cells
Two genetically identical daughter cells
Which of the following shows the moist heat methods in order of the temperature used (highest to lowest)? Ultrahigh>Autoclave>Boiling>Batch Pasteurization Autoclave>Ultrahigh>Batch Pasteurization>Boiling Ultrahigh> Boiling>Batch Pasteurization >Autoclave Ultrahigh>Boiling>Autoclave>Batch Pasteurization
Ultrahigh>Autoclave>Boiling>Batch Pasteurization
Which of the following statements about helminths is FALSE? Some have male and female reproductive organs in one animal. They are multicellular animals. All are parasites. They are heterotrophic. They have eukaryotic cells.
All are parasites.
During his research on West Nile virus, Bill learned that this virus is placed within a functional grouping known as arboviruses. What is meant by the term arbovirus? Select all that apply. An arbovirus is an arthropod-borne virus. An arbovirus is a virus isolated in Ann Arbor, Michigan. An arbovirus is maintained in nature through biological transmission. An arbovirus is a virus that originated from plants.
An arbovirus is an arthropod-borne virus. An arbovirus is maintained in nature through biological transmission.
What is the primary benefit of vaccination? Unvaccinated persons can never mount an immune response to a pathogen. Vaccinated persons get used to the symptoms of a disease. Vaccines provide antibodies against the pathogen that persist forever in the body. An immune response will occur quicker upon future exposure to the pathogen.
An immune response will occur quicker upon future exposure to the pathogen.
Which statement regarding cancer immunotherapy is FALSE? Monoclonal antibodies are a promising tool for cancer treatment delivery. Cancer vaccines may be either therapeutic or prophylactic. Cancer immunotherapy is preferable to radiation therapy because it does not involve causing damage to healthy cells. An immunotoxin is an antigen combined with a toxic agent.
An immunotoxin is an antigen combined with a toxic agent.
Which of the following would be an example of an infection initiated via the parenteral route? An individual contracts a gastrointestinal infection by consuming contaminated water. An individual contracts a hookworm infection as a result of walking around outside barefoot. An individual contracts gonorrhea as a result of unprotected sex. An individual contracts hepatitis B from an accidental stick with a contaminated needle.
An individual contracts hepatitis B from an accidental stick with a contaminated needle.
Which of the following best describes vaccination? An individual is exposed to a killed pathogen, an inactivated pathogen, or a component of a pathogen. The individual is protected from subsequent exposures because the body produces macrophages that live a long time and can remember the pathogen. An individual is exposed to a killed pathogen, an inactivated pathogen, or a component of a pathogen. The individual is protected from subsequent exposures to the pathogen because the innate immune system is stimulated. An individual is exposed to a killed pathogen, an inactivated pathogen, or a component of a pathogen. The individual is protected from subsequent exposures to the pathogen because the adaptive immune system is stimulated to produce memory B cells and memory T cells, which protect from subsequent exposures. An individual is exposed to a killed pathogen, an inactivated pathogen, or a component of a pathogen. The individual is protected from subsequent exposures to the pathogen because the body has an inflammatory response, which protects the individual from subsequent exposures.
An individual is exposed to a killed pathogen, an inactivated pathogen, or a component of a pathogen. The individual is protected from subsequent exposures to the pathogen because the adaptive immune system is stimulated to produce memory B cells and memory T cells, which protect from subsequent exposures.
Which of the following would be considered a fomite? An infected toy A tick Contaminated water A fly
An infected toy
Why is DNA replication essential for a cell? An organism must copy its DNA to pass genetic information to its offspring. All organisms require two copies of DNA. Because DNA is double-stranded. It allows the organism to repair any mistakes.
An organism must copy its DNA to pass genetic information to its offspring.
Into which group would you place a multicellular organism that has a mouth and lives inside the human liver? Animalia Fungi Proteobacteria (gram-negative bacteria) Plantae Firmicutes (gram-positive bacteria)
Animalia
Although cholera can be treated with antibiotics, data suggest that antibiotic treatment alone is NOT the most effective therapy. Which of the following statements describes the most likely reason for supplementing antibiotic therapy? As with V. cholerae, the acidic environment of the stomach can have a negative impact on antibiotic activity. The production of cholera toxin helps V. cholerae resist antibiotic treatment. Antibiotic therapy addresses only the growth of V. cholerae; it doesn't address the extreme dehydration suffered by a person infected with V. cholerae. Because V. cholerae is a gram-negative organism, it is not very effectively treated with antibiotics.
Antibiotic therapy addresses only the growth of V. cholerae; it doesn't address the extreme dehydration suffered by a person infected with V. cholerae.
Why are archaea and bacteria—both collections of prokaryotic organisms—grouped into different domains while organisms like fungi and animals are in the same domain? The DNA sequences of bacteria and archaea are more different than animals and fungi. Bacteria and archaea differ significantly in their intracellular organization and structure, but fungi and animals have similar intracellular structure. Bacteria and archaea differ significantly in their rRNA sequences, but fungi and animals share some rRNA characteristics. Fungi and animals look much more similar than bacteria and archaea.
Bacteria and archaea differ significantly in their rRNA sequences, but fungi and animals share some rRNA characteristics.
Which of the following statements concerning phagocytosis is true? Phagocytes ingest microorganisms by using protein transporters that are specific for the bacteria. Bacteria are digested when the phagosome fuses with a lysosome. Phagocytes cannot ingest microorganisms unless they are coated with antibodies. Adherence always requires opsonization.
Bacteria are digested when the phagosome fuses with a lysosome.
In which stage does formation of mature viruses occur? Release Assembly Attachment Biosynthesis Penetration
Assembly
Which of the following statements is TRUE? Members of a symbiotic relationship cannot live without each other. At least one member must not benefit in a symbiotic relationship. At least one member must benefit in a symbiotic relationship. A parasite is not in symbiosis with its host. Symbiosis refers to different organisms living together and benefiting from each other.
At least one member must benefit in a symbiotic relationship.
The CDC is located in New York City, NY. Washington, DC. Atlanta, GA. Las Angeles, CA. Chicago, IL.
Atlanta, GA.
Which type of vaccine could possibly cause a person to develop the disease? Toxoid vaccine and inactivated killed vaccine Inactivated killed vaccine Toxoid vaccine Attenuated live vaccine
Attenuated live vaccine
A hybridoma results from the fusion of a(an) antigen with a B cell. myeloma cell with a virus. antigen with an antibody. B cell with a myeloma cell. B cell with a T cell.
B cell with a myeloma cell.
Which of the following is NOT a characteristic of cellular immunity? The cells originate in bone marrow. Cells are processed in the thymus gland. T cells react with antigens. It can inhibit the immune response. B cells make antibodies.
B cells make antibodies.
TH2 cells produce cytokines that activate B cells. cytotoxic T-cells. macrophages. natural killer cells.
B cells.
Which domain of the A-B toxin binds to cell surface receptors on the host cell? A-B toxins do not bind to cell surfaces. Both the A and B domains have the ability to bind to cell surface receptors. A domain B domain
B domain
How is bacterial translation different from eukaryotic translation? Bacteria can begin translation before transcription has terminated. Bacterial translation does not involve ribosomes. mRNA is read 3' to 5'.
Bacteria can begin translation before transcription has terminated.
__________________ stimulated with ___________ differentiate into __________, which secrete antibodies into the bloodstream. Phagocytes, antigen, B-cells Antigen, plasma cells, B-cells B-cells, antigen, plasma cells Plasma cells, antigen, B-cells
B-cells, antigen, plasma cells
Which pair of molecules do NOT directly interact with one another? BCR and TCR CD4 and MHC-II BCR and epitope CD8 and MHC-I
BCR and TCR
Which level of biosafety (BSL) is appropriate for handling organisms that present a moderate risk of infection? BSL-4 BSL-3 BSL-2 BSL-1
BSL-2
Which of the following do you expect to be MOST resistant to high temperatures? Eschericia coli Bacillus subtilis Staphylococcus aureus Neisseria gonorrhoeae Streptococcocus pyogenes
Bacillus subtilis
Based on the animation, which of the following is cleaved by C1? C2 and C4 C5 and C4 C5 C2 C4
C2 and C4
Based on the animation, which of the following is responsible for cleaving C3? C2aC4b C4aC2b C5bC6C7 C1
C2aC4b
Which of the following statements about the classical pathway of complement activation is FALSE? C3 is not involved in the classical pathway. The C1 protein complex is initiated by antigen-antibody complexes. C1 is the first protein activated in the classical pathway. Cleaved fragments of some of the proteins act to increase inflammation. C3b causes opsonization.
C3 is not involved in the classical pathway.
The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway beginning with the activation of C1. C2. C3. C5. C6.
C3.
In the classical pathway, which of the following directly activates cellular responses? C5bC6C7 C2aC4b C3a and C5a C3a, C5a, and C5bC6C7 C4aC2bC3b C3b
C3a, C5a, and C5bC6C7
Based on the animation, which of the complement proteins can directly bind to the surface of a bacterial cell? C5b C3b C2b C2a C4a
C3b
Which complement protein is used as an opsonin? C4a C7 C5b C2a C3b C3a
C3b
Which event happens first during cytotoxic T-cell activation? Production of IL-2 and gamma-interferon receptors Secretion of granzymes and perforin CD8 binds to MHC molecules of infected cells Clonal proliferation
CD8 binds to MHC molecules of infected cells
Which of the following destroys virus-infected cells? Treg dendritic cells B cells TH CTL
CTL
A healthy immune system destroys cancer cells with CD+ T cells. CTLs and activated macrophages. CTLs. tumor-specific antigens. activated macrophages.
CTLs and activated macrophages.
Which of the following is NOT an enteric? Escherichia Campylobacter Shigella Enterobacter Salmonella
Campylobacter
Based on the lab results, which organism is most likely causing Tori's new symptoms? Trichomonas vaginalis Candida albicans Gardnerella vaginalis Sporothrix schenckii
Candida albicans
Thrush and vaginitis are caused by Staphylococcus aureus. Candida albicans. herpesvirus. Streptococcus pyogenes. Chlamydia trachomatis.
Candida albicans
Yeast infections are caused by Histoplasma. Candida albicans. Aspergillus. Penicillium. Saccharomyces cerevisiae.
Candida albicans.
The following data were obtained from a broth dilution test. Concentration of Antibiotic X Growth Growth in Subculture 2 μg/ml + + 10 μg/ml - + 15 μg/ml - - 25 μg/ml - - In the table, the minimal bactericidal concentration of antibiotic X is 15 μg/ml. 10 μg/ml. 25 μg/ml. 2 μg/ml. The answer cannot be determined based on the information provided.
15 μg/ml.
In what year did Stanley Prusiner discover prions? 1997 1928 1979 1982
1982
1. 9+2 flagella 2. Nucleus 3. Plasma membrane 4. Peptidoglycan 5. Mitochondrion 6. Fimbriae In the table, which features are found in all Eukarya? 2, 3 1, 2, 5 2, 3, 5 1, 4, 6 3, 5
2, 3, 5
Donor Recipient 1. AB, Rh- AB, Rh+ 2. A, Rh+ A, Rh- 3. A, Rh+ O, Rh+ 4. B, Rh- B, Rh+ 5. B, Rh+ A, Rh+ Which blood transfusions in the table are incompatible? 2, 3, and 5 1 and 2 1, 2, and 3 3 and 4 2 and 5
2, 3, and 5
Place the following steps of phagocytosis in the order that they occur: Endosome fuses with lysozome Dendritic cell engulfs Rhinovirus Epitopes are attached to MHC-II Digestion of the Rhinovirus MHC-II plus the attached epitope move to the outside of the dendritic cell 2,1,4,3,5 2,1,3,4,5 2,4,1,3,5 1,2,4,3,5
2,1,4,3,5
Correctly order the steps involved cellular immunity: The Tc recognizes the infected host cell The Tc interacts with epitope presented by MHC-I on the dendritic cell The Tc secretes perforin and granzyme, causing apoptosis The helper T cell activates the Tc cell 4,2,1,3 2,4,1,3 1,2,4,3 2,1,3,4
2,4,1,3
According to the animation, surgical infections account for what percentage of nosocomial infections? 8% 15% 40% 11% 20%
20%
Which of the following places these items in the correct order for DNA-virus replication? 1. Maturation 2. DNA synthesis 3. Transcription 4. Translation 4; 3; 2; 1 2; 3; 4; 1 3; 4; 1; 2 4; 1; 2; 3 1; 2; 3; 4
2; 3; 4; 1
Which of the following antibiotics are used to treat fungal infections? 1. aminoglycosides 2. cephalosporins 3. griseofulvin 4. polyenes 5. bacitracin 1, 2, and 3 3 and 4 3, 4, and 5 4 and 5 All of these antibiotics are used to treat fungal infections.
3 and 4
A microbe reproduces by binary fission every 20 minutes under favorable conditions. How long would 10 generations take and how many bacteria would be present if all the conditions were just right? 18 hours and 40 minutes, producing 1 million bacteria 24 hours, producing 262,144 bacteria 2 hours and 10 minutes, producing 1,048,576 bacteria 3 hours 20 minutes, producing 1,024 bacteria
3 hours 20 minutes, producing 1,024 bacteria
Put the following steps of bacterial replication in the correct order, starting from a parent cell. 1. Cell elongation 2. Septum formation 3. Chromosome replication 4. Separation of daughter cells 1, 4, 3, 2 3, 2, 1, 4 3, 1, 2, 4 2, 4, 3, 1 4, 3, 1, 2
3, 1, 2, 4
1. 9+2 flagella 2. Nucleus 3. Plasma membrane 4. Peptidoglycan 5. Mitochondrion 6. Fimbriae In the table, which feature(s) is (are) found only in prokaryotes? 1 2 2, 4, 5 4, 6 1, 2, 3
4, 6
Most fungi grow best at pH 1. 5. 7. 9. 14.
5
According to the animation, ribosomes move along the mRNA in which direction? 5' to 3' Either 5' to 3' or 3' to 5' 3' to 5'
5' to 3'
In which direction does DNA polymerase synthesize the new DNA strand? Both 5' to 3' and 3' to 5' 5' to 3' 3' to 5'
5' to 3'
In an agglutination test, eight serial dilutions to determine antibody titer were set up. Tube #1 contained a 1:2 dilution; tube #2, a 1:4, etc. If tube #6 is the last tube showing agglutination, what is the antibody titer? 1:6 6 64 32 1:32
64
Most bacteria grow best at pH 1. 5. 7. 9. 14.
7
Which concentration of ethanol is the most effective bactericide? 100% 70% 50% 40% 30%
70%
What is the temperature used for the extension step? 94 °C 72 °C 60 °C
72 °C
What is the sequence of the temperatures of a typical PCR reaction? 94 °C, 60 °C, 72 °C 60 °C, 72 °C, 94 °C 72 °C, 60 °C, 94 °C 72 °C, 94 °C, 60 °C 94 °C, 72 °C, 60 °C
94 °C, 60 °C, 72 °C
Based on the animation, what is transferred during bacterial conjugation? A bacterial chromosome A bacterial plasmid RNA A conjugation pilus
A bacterial plasmid
The structures illustrated in the figure are composed of RNA. Capsids. DNA. Capsomeres. DNA or RNA.
Capsomeres.
How can capsules enable bacteria to evade the immune system? Capsules can bind up IgA, rendering it inactive. A capsule is a superantigen that distracts the immune system. Capsules block the complement biding sites on the surface of the pathogen.
Capsules block the complement biding sites on the surface of the pathogen.
Why is cell growth typically graphed logarithmically? Cells can change their phase whenever convenient, a phenomenon clearly shown on a log graph. Cells need time to switch metabolic machinery when placed in new media. Cell growth is rapid, and plotting the log of the number of cells versus the generation on a logarithmic graph produces a linear graph. It allows one to also graph cell death.
Cell growth is rapid, and plotting the log of the number of cells versus the generation on a logarithmic graph produces a linear graph.
Which of the following can release histamines? Wood from a splinter Cells from damaged tissues and the complement pathway Cells from damaged tissues The complement system Invading bacterial cells
Cells from damaged tissues and the complement pathway
Which of the following statements concerning cellular immunity is FALSE? T cells respond to antigens when the antigens bind to receptors on their surface. The thymus is necessary for development of cells involved in cellular immunity. The lymphocytes involved with cellular immunity are found primarily in lymphoid organs and blood. Cellular immunity involves cells that recognize antigens and make specific antibodies against them.
Cellular immunity involves cells that recognize antigens and make specific antibodies against them.
What complement result involves the use of phagocytes? Chemotaxis and opsonization Chemotaxis Opsonization Cytolysis
Chemotaxis and opsonization
What is meant by selective toxicity? Chemotherapeutic agents should work on many different targets on a pathogen. Chemotherapeutic agents should work on certain types of pathogens. Chemotherapeutic agents should have only one mode of action. Chemotherapeutic agents should act against the pathogen and not the host.
Chemotherapeutic agents should act against the pathogen and not the host.
Which of the following prion diseases is found in deer and elk? Bovine spongiform encephalopathy Scrapie Variant Creutzfeldt-Jakob disease Chronic wasting disease
Chronic wasting disease
What type of nosocomial infection is likely to arise from intravenous catheterizations? Urinary tract Cutaneous Lower respiratory Bacteremia Surgical
Bacteremia
Early indication of immune system failure is provided by: high levels of HIV virus in the blood Seroconversion of HIV Falling levels of CD4+ cells
Falling levels of CD4+ cells
A highly specific diagnostic test will have very few false negative reactions. True False
False
All hypersensitivities involve antibody-antigen reactions. True False
False
All stem cells are derived from embryonic stem cells. True False
False
An injection of naked DNA into muscle cells to induce an immune response against the proteins encoded by the DNA is an example of a subunit vaccine. True False
False
Any process that destroys the non-spore forming contaminants on inanimate objects is sterilization. True False
False
Bacteria typically contain multiple chromosomes. True False
False
Desiccation is a reliable form of sterilization. True False
False
In a vaccine preparation, the term attenuated means that the agent does NOT replicate. True False
False
Microorganisms placed in high concentrations of salts and sugars undergo lysis. True False
False
Most cases of hookworm infection are acquired by ingestion of eggs in contaminated food or water. True False
False
Photosynthetic organisms always produce oxygen gas as a metabolic byproduct. True False
False
Skin tests are reliable indicators for the diagnosis of food-related allergies. True False
False
The Platyhelminthes group includes roundworms, tapeworms, and flukes. True False
False
The highest level in the taxonomic hierarchy is "Kingdom." True False
False
The human body is typically free of archaeal species. True False
False
The term biotechnology refers exclusively to the use of genetically engineered organisms for the production of desired products. True False
False
Vaccines against HIV have proven to be very effective in halting the spread of disease. True False
False
Xenotransplantation is an effective alternative to using isografts. True False
False
I have a new test for determining whether a patient is infected with the influenza virus. It is very specific but not very sensitive. What does this mean? Both false-positives and false-negatives will be rare. False-positives will happen frequently, but false-negatives will be rare. False-positives will be rare, but false-negatives may happen frequently. False-positives and false-negatives will happen with high frequency.
False-positives will be rare, but false-negatives may happen frequently.
In the figure, when is the prevalence the highest? March The answer cannot be determined based on the information provided. January February July
February
Which of the following would be the first sign of an infection that resulted in the release of endotoxin? Pain Nausea Weakness Fever
Fever
Gram-positive organisms with low G + C content are commonly called __________. Firmicutes mycobacteria proteobacteria Spirochaetes
Firmicutes
In the last segment of the animation, how many regions of the world experience the pandemic during April of year four? Four Two Six Five
Five
Which of the following features of Salmonella prevent it from being phagocytosed? Fimbriae Flagella Invasins
Flagella
Which of the following is mismatched? Ehrlich - magic bullet theory Florey and Chain - identification of Penicillium as the producer of penicillin Fleming - identification of penicillin Kirby and Bauer - disc-diffusion method None of these is mismatched.
Florey and Chain - identification of Penicillium as the producer of penicillin
Assuming Rh compatibility is present, which of the following individuals would be able to receive donor blood from any of the four blood types (A, B, AB, and O)? A O AB B
AB
TLRs attach to all of the following EXCEPT AMPs. peptidoglycan. PAMPs. LPS. flagellin.
AMPs.
Which of the following is NOT a step that ultimately leads to antibody production? Activation of helper T cells by dendritic cells Activation of cytotoxic T cells by helper T cells Differentiation of plasma cells Immature B cells conducting surveillance for foreign epitopes
Activation of cytotoxic T cells by helper T cells
Which of the following statements is true? Adaptive defenses include both humoral and cellular immunity. Memory B cells are typically established when the B cell binds to an antigen. Adaptive defenses include humoral immunity only. Innate defenses are enough to keep a person healthly.
Adaptive defenses include both humoral and cellular immunity.
The Pap test for cervical cancer involves microscopic examination of cervical cells for cancerous cells. A new, rapid diagnostic test to detect human papilloma virus (HPV) DNA before cancer develops is done without microscopic exam. The steps involved in this FastHPV test are listed below. What is the second step? Add an RNA probe for HPV DNA. Add enzyme-linked antibodies against DNA-RNA. add enzyme substrate. Lyse human cells. The order is unimportant.
Add an RNA probe for HPV DNA.
When do helper T-cells develop into TH1 or TH2 cells? Before autostimulation Immediately after the binding of the CD4 receptor After proliferation into a clonal population After B cell activation
After proliferation into a clonal population
__________ reactions are used to detect antibodies for relatively large pathogens, such as bacteria. For these tests, the antigen is mixed with the test sample at various dilutions. Reaction mixes are then monitored for the formation of visible aggregates. Agglutination Western blotting Precipitation ELISA
Agglutination
Which statement regarding agricultural biotechnology is FALSE? Scientists have created plants that produce an insect toxin originally found in bacteria. Scientists have created plants that are resistant to herbicides by using a mutant enzyme gene from Salmonella. Scientists have used gene silencing to create tomatoes with a longer shelf life. Agricultural biotechnology is extremely limited because foreign genes cannot be inserted into plant cells.
Agricultural biotechnology is extremely limited because foreign genes cannot be inserted into plant cells.
Which microorganism requires the low pH inside a phagolysosome in order to reproduce? Streptococcus pyogenes Haemophilus influenzae Streptococcus pneumoniae Coxiella burnetii
Coxiella burnetii
The following results were obtained from a disk-diffusion test for microbial susceptibility to antibiotics. Staphylococcus aureus was the test organism. Antibiotic Zone of Inhibition A 3 mm B 7 mm C 0 mm D 10 mm In the table, the most effective antibiotic tested was A. B. C. D. The answer cannot be determined based on the information provided.
D.
Where do Salmonella pathogens grow and replicate in the infected host? Inside Shigella cells Inside phagocytes Inside M cells Inside intestinal epithelial cells
Inside phagocytes
Which of the following are likely to be found on an MHC-I protein? Membranes from a neighboring dead host cell Bacterial DNA Damaged mitochondrial fragment Bacterial flagella Bacterial cell wall fragment
Damaged mitochondrial fragment
According to the animation, on which day does the production of IgG occur in the secondary response? Day fifteen Day five Day ten Day two
Day five
Which proteins on the antigen-presenting cell are recognized by the helper T-cell? IL-2 receptors CD8 receptors IL-1 receptors MHC proteins
MHC proteins
Most phagocytes are types of white blood cells, but not all white blood cells participate in this process. Select the cell types that are actively phagocytic. Macrophage Basophil T lymphocyte Neutrophil B lymphocyte Dendritic cell Eosinophil Erythrocyte
Macrophage Neutrophil Dendritic cell Eosinophil
Which of the cells listed below can present antigens on Class II MHC proteins? Virus infected epithelial cells Healthy epithelial cells Tumor cells Macrophages
Macrophages
Which of the following lacks a cell wall? Mycobacterium Nocardia Borrelia Mycoplasma Clostridium
Mycoplasma
According to your Concept Map, which of the following organisms exhibits antigenic variation? S. pneumoniae H. influenzae N. gonorrheae Mycobacterium tuberculosis
N. gonorrheae
Use the dichotomous key in the table to identify a gram-negative coccus. Micrococcus Streptococcus Pseudomonas Neisseria Staphylococcus
Neisseria
Infants may acquire a serious form of conjunctivitis during birth if they are born to a mother infected with __________. Acanthamoeba species Chlamydia trachomatis Haemophilus influenzae Neisseria gonorrhoeae
Neisseria gonorrhoeae
Meningitis and gonorrhea are caused by Neisseria species. Pseudomonas species. measles virus.
Neisseria species.
Consider a gram-negative human pathogen isolated from marine mammals. This pathogen is subjected to a series of tests and found to have the following characteristics: oxidase-positive; does not hydrolyze urea; produces indole; does not produce acetoin. Which of the following could it be? Yersinia enterocolitica Mannheimia haemolytica Klebsiella pneumoniae Pasteurella multocida
Pasteurella multocida
_______________ is a process used to destroy pathogens in food and drinks. It must be done at a lower temperature than other methods so that _______________. Pasteurization; beneficial microorganisms are not killed Pasteurization; the taste of the food or drink will not be altered autoclaving; the taste of the food or drink will not be altered autoclaving; beneficial microorganisms are not killed
Pasteurization; the taste of the food or drink will not be altered
Which of the following organisms requires an additional nonhuman host to complete its life cycle? Plasmodium species Necator americanus Ascaris lumbricoides Enterobius vermicularis
Plasmodium species
An enzyme that copies DNA to make a molecule of RNA is DNA helicase. DNA ligase. DNA polymerase. transposase. RNA polymerase.
RNA polymerase.
Most RNA viruses carry which of the following enzymes? DNA-dependent DNA polymerase reverse transcriptase RNA-dependent RNA polymerase ATP synthase lysozyme
RNA-dependent RNA polymerase
Pus is comprised of collected cells from damaged tissue. unused histamines and leukotrienes. dead phagocytes. excess fluid from leaky blood vessels.
dead phagocytes.
In macrophages and dendritic cells (so-called antigen-presenting cells) some small parts of the phagocytosed particle are presented to other cells of the immune system. If you were to draw an arrow leading to "antigen presentation" as described above, from which word would it extend? digestion ingestion exocytosis adherence
digestion
You note that the body temperature of one of your patients is starting to increase. As a result, you can infer that all of the following may be occurring in this patient EXCEPT __________. constriction of blood vessels dilation of blood vessels increased metabolic rate shivering
dilation of blood vessels
In mid-December, a woman with insulin-dependent diabetes who had been on prednisone fell and received an abrasion on the dorsal side of her right hand. She was placed on penicillin. By the end of January, the ulcer had not healed, and she was referred to a plastic surgeon. On January 30, a swab of the wound was cultured at 35°C on blood agar. On the same day, a smear was made for Gram staining. The Gram stain showed large (10 µm) cells. Brownish, waxy colonies grew on the blood agar. Slide cultures set up on February 1 and incubated at 25°C showed septate hyphae and single conidia. The most likely cause of the infection is a gram-negative bacterium. dimorphic fungus. parasitic alga. protozoan. yeast.
dimorphic fungus.
Which of the following is a test to determine a patient's blood type by mixing the patient's red blood cells with antisera? direct agglutination reaction passive agglutination reaction immunofluorescence neutralization reaction precipitation reaction
direct agglutination reaction
A test used to identify Streptococcus pyogenes in a patient's throat swab is the hemagglutination-inhibition test. hemagglutination test. indirect ELISA test. indirect fluorescent-antibody test. direct fluorescent-antibody test.
direct fluorescent-antibody test.
An agent used to reduce the number of bacteria on a toilet would most accurately be called a(n) disinfectant. virucide. antiseptic. fungicide. aseptic.
disinfectant.
Antimicrobial peptides work by hydrolyzing peptidoglycan. disrupting the plasma membrane. inhibiting cell-wall synthesis. inhibiting protein synthesis. complementary base pairing with DNA.
disrupting the plasma membrane.
Assume a patient had chickenpox (human herpesvirus 3) as a child. Which line on the graph in the figure would show the number of viruses present in this person as a 60-year-old with shingles (human herpesvirus 3)? a b c d e
e
In the figure, what can attach to a host cell? b and c a and c b a and d e
e
In the figure, which letter on the graph indicates the highest antibody titer during the patients response to a second antigen? a b c d e
e
Sulfanilamides interfere with __________. protein synthesis in fungi anaerobic metabolism in protozoa folic acid synthesis in bacteria protein synthesis in helminths
folic acid synthesis in bacteria
A needlestick is an example of vector. vehicle transmission. droplet transmission. fomite. direct contact.
fomite.
Scabies is transmitted by respiratory secretions. water. food. soil. fomites.
fomites.
Each of the following provides protection from phagocytic digestion EXCEPT leukocidins. biofilms. M protein. capsules. formation of phagolysosomes.
formation of phagolysosomes.
The chemical mediators of anaphylaxis are the proteins of the complement system. antigen-antibody complexes. found in basophils and mast cells. antigens. antibodies.
found in basophils and mast cells.
A new chemotherapeutic agent is developed that alters the structure of all thymines in DNA. These thymines are then misread during the production of mRNA. Which of the following could NOT result from this type of mutation? missense mutation silent mutation nonsense mutation frameshift mutation
frameshift mutation
A base insertion or deletion in the translated region of the gene may lead to frameshift mutation. silent mutation. nonsense mutation. missense mutation.
frameshift mutation.
Which method below is used to preserve food by slowing the metabolic processes of foodborne microbes? ionizing radiation nonionizing radiation pasteurization lyophilization freezing
freezing
Which of the following infections are also caused by C. albicans? Select all that apply. syphilis fulminating disease genital warts oral thrush
fulminating disease oral thrush
A drug that inhibits mitosis, such as griseofulvin, would be more effective against fungi. gram-positive bacteria. mycobacteria. wall-less bacteria. gram-negative bacteria.
fungi
Ringworm is caused by a(n) fungus. trematode. protozoan. cestode. nematode.
fungus
The ability of Vibrio cholerae to cause disease depends on a number of factors. Which of the following are requirements for causing disease within a host? Select all that apply. depleting the host of nutrients at the site of infection production of exotoxins gaining access to the host via a portal of entry direct damage of host tissues adherence to host tissues evasion of host defenses
gaining access to the host via a portal of entry adherence to host tissues evasion of host defenses
Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper? sunlight autoclave microwaves gamma radiation ultraviolet radiation
gamma radiation
Helminthic diseases are usually transmitted to humans by respiratory route. gastrointestinal route. genitourinary route. vectors. aerosols.
gastrointestinal route.
Which of the following pairings of recombinant DNA techniques and applications does NOT match? gene therapy: replacing a defective gene gene silencing: production of subunit vaccines PCR: making many copies of a segment of DNA genetic modification of yeast: production of purified insulin
gene silencing: production of subunit vaccines
A clone is a mound of cells on an agar medium. genetically identical cells derived from a single cell. a genetically engineered cell. a taxon composed of species. None of the answers is correct.
genetically identical cells derived from a single cell.
In the scientific name Enterobacter aerogenes, Enterobacter is the kingdom. specific epithet. family. genus. order.
genus
Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages carry plasmids. kill the bacteria, causing release of endotoxins. kill human cells. produce toxins. give new gene sequences to the host bacteria.
give new gene sequences to the host bacteria.
Which of the following is an example of a metabolic activity that could be used to measure microbial growth? turbidity glucose consumption MPN standard plate count direct microscopic count
glucose consumption
The swelling associated with inflammation decreases when the fluid returns to the blood. is lost as perspiration. is excreted in urine. goes into lymph capillaries. is transported into macrophages.
goes into lymph capillaries.
Attachment of HIV to the target cell depends on gp120 binding to the CD4+ plasma membrane. gp120 combining with the chemokine receptor CCR5. gp120 combining with the CD4+ receptor. gp41 binding to the CD4+ receptor. CXCR4 binding to the CD4+ receptor.
gp120 combining with the CD4+ receptor.
Antibiotics can lead to septic shock if used to treat protozoan infections. gram-negative bacterial infections. gram-positive bacterial infections. viral infections. helminth infestations.
gram-negative bacterial infections.
Which one of the following does NOT contribute to the incidence of nosocomial infections? lapse in aseptic techniques lack of handwashing gram-negative cell walls lack of insect control antibiotic resistance
gram-negative cell walls
Salmonella, Shigella, Yersinia, and Serratia are all gram-positive aerobic cocci. fermentative. pathogens. endospore-forming bacteria. gram-negative facultatively anaerobic rods.
gram-negative facultatively anaerobic rods.
If penicillin G is chosen as the best treatment for a given infection, what microorganisms are most likely the cause? fungi gram-positive bacteria viruses gram-negative bacteria
gram-positive bacteria
Which of the following correctly lists, in increasing order, the resistance of microorganisms to chemical biocides? gram-positive bacteria, fungi, endospores, prions gram-negative bacteria, fungi, protozoan cysts, mycobacteria protozoan cysts, fungi, gram-negative bacteria, prions prions, gram-negative bacteria, vegetative protozoa, gram-positive bacteria
gram-positive bacteria, fungi, endospores, prions
All of the following are characteristic of Pseudomonas aeruginosa EXCEPT resistance to many types of disinfectants and antibiotics. rod-shaped. growth in moist environments. gram-positive cell wall. production of pyocyanin.
gram-positive cell wall.
Staphylococcus and Streptococcus can be easily differentiated in a laboratory by which one of the following? growth in high salt concentrations Gram stain reaction glucose fermentation cell shape ability to cause disease
growth in high salt concentrations
All of the following are examples of entry via the parenteral route EXCEPT surgery. bite. skin cut. hair follicle. injection.
hair follicle.
Surface-active agents act by decreasing surface tension so that microbes can be more easily removed. All of the following agents use this mechanism of action EXCEPT __________. soaps and detergents quaternary ammonium compounds (quats) acid-anionic sanitizers halogens
halogens
A viral species is a group of viruses that has the same genetic information and ecological niche. has the same morphology and nucleic acid. infects the same cells and cause the same disease. cannot be defined.
has the same genetic information and ecological niche.
Which of the following would NOT be an example of a common allergen? dust mites peanuts pollen hay fever
hay fever
Which of the following results in lethal damage to nucleic acids? heat radiation certain chemicals heat and radiation heat, radiation, and some chemicals
heat, radiation, and some chemicals
Niclosamide prevents ATP generation in mitochondria. You would expect this drug to be effective against viruses. gram-negative bacteria. helminths. gram-positive bacteria. Mycobacterium tuberculosis.
helminths.
According to the animation, B cells interact directly with helper T cells. the complement system. inflammation. phagocytes.
helper T cells.
Patient's serum, influenza virus, and red blood cells are mixed in a tube. What happens if the patient has antibodies against influenza virus? complement fixation agglutination hemagglutination-inhibition hemolysis hemagglutination
hemagglutination-inhibition
Worldwide, the primary method of transmission of HIV is blood transfusions. heterosexual intercourse. nosocomial. intravenous drug use. homosexual intercourse.
heterosexual intercourse.
Which of the following arthropods does NOT transmit diseases by sucking blood from a human host? mosquitoes kissing bugs fleas lice houseflies
houseflies
Three weeks after a river rafting trip, three family members experienced symptoms of coughing, fever, and chest pain. During the rafting trip, the family had consumed crayfish that they caught along the river banks. An examination of the patients sputum revealed helminth eggs, and serum samples were positive for antibodies to Paragonimus. All of the family members recovered following treatment with praziquantel. In the Paragonimus life cycle, the crayfish are the definitive host and humans are the intermediate host. both humans and crayfish are definitive hosts. the source of the infection was the river water. both humans and crayfish are intermediate hosts. humans are the definitive host and crayfish are the intermediate host.
humans are the definitive host and crayfish are the intermediate host.
In the malaria parasite life cycle humans are the intermediate host. mosquitoes are the definitive host. mosquitoes are the vector. humans are the intermediate host and mosquitos are the definitive host. humans are the intermediate host and mosquitoes are both the definitive host and the vector.
humans are the intermediate host and mosquitoes are both the definitive host and the vector.
If a prodromal period exists for a certain disease, it should occur prior to illness. incubation. decline. convalescence.
illness
In rheumatoid arthritis, IgM, IgG, and complement deposit in joints. This is an example of cell-mediated autoimmunity. acquired immunodeficiency. immune complex autoimmunity. cytotoxic autoimmunity. immunosuppression.
immune complex autoimmunity.
Lysogeny can result in all of the following EXCEPT specialized transduction. immunity to reinfection by any phage. phage conversion. immunity to reinfection by the same phage. acquisition of new characteristics by the host cell.
immunity to reinfection by any phage.
Treatment with certain drugs to reduce transplant rejection can cause immunologic enhancement. immunologic surveillance. immunotherapy. autoimmunity. immunosuppression.
immunosuppression.
Which of the following utilizes a combination of monoclonal antitumor antibody and immunotoxin? immunotherapy immune complex immunologic enhancement immunosuppression immunologic surveillance
immunotherapy
The influenza vaccine is an example of a(n) inactivated killed vaccine. toxoid vaccine. DNA vaccine. conjugated vaccine.
inactivated killed vaccine.
Dead Bordetella pertussis can be used in a(n) inactivated whole-agent vaccine. attenuated whole-agent vaccine. conjugated vaccine. subunit vaccine. toxoid vaccine.
inactivated whole-agent vaccine.
Bacterial growth is defined as increase in cellular proteins. increase in cell length. increase in cell metabolic processes. increase in bacterial cell population.
increase in bacterial cell population
Mutagens decrease the likelihood of mutations in DNA. come in two basic forms: ionizing and nonionizing radiation. are the sole cause of mutations in DNA. increase the likelihood of mutations in DNA.
increase the likelihood of mutations in DNA.
Which of the following is an effect of opsonization? increased adherence of phagocytes to microorganisms inflammation increased margination of phagocytes increased diapedesis of phagocytes cytolysis
increased adherence of phagocytes to microorganisms
One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in no bacterial growth because washing removes their food source. body odor. fewer diseases. normal microbiota returning immediately. increased susceptibility to disease.
increased susceptibility to disease.
In which of the following patterns of disease does the patient experience no signs or symptoms? prodromal decline convalescence incubation incubation and convalescence
incubation and convalescence
Which of the following tests is MOST useful in determining the presence of AIDS antibodies? complement fixation direct fluorescent-antibody agglutination neutralization indirect ELISA
indirect ELISA
Which of the following is a pregnancy test used to find the fetal hormone HCG in a woman's urine using anti-HCG and latex spheres? direct agglutination reaction indirect agglutination reaction immunofluorescence neutralization reaction precipitation reaction
indirect agglutination reaction
A cold transmitted by a facial tissue is an example of which form of disease transmission? vehicle transmission indirect contact transmission vector droplet transmission
indirect contact transmission
A patient acquires an infection by touching a contaminated door handle. Which mode of transmission best describes this scenario? vehicle transmission droplet transmission direct contact transmission indirect contact transmission
indirect contact transmission
A test used to detect anti-Rickettsia antibodies in a patient's serum is the indirect fluorescent-antibody test. direct fluorescent-antibody test.
indirect fluorescent-antibody test.
A test used to identify antibodies against Treponema pallidum in a patient's serum is the direct fluorescent-antibody test. direct agglutination test. indirect fluorescent-antibody test. hemagglutination-inhibition test. direct ELISA test.
indirect fluorescent-antibody test.
An enzyme produced in response to the presence of a substrate is called a(n) repressible enzyme. restriction enzyme. inducible enzyme. operator. promoter.
inducible enzyme.
Which of the following mechanisms is used by gram-negative bacteria to cross the blood-brain barrier? producing toxins inducing TNF producing fimbriae inducing endocytosis antigenic variation
inducing TNF
A viroid is a(n) infectious protein. capsid without nucleic acid. infectious piece of RNA without a capsid. provirus. complete, infectious virus particle.
infectious piece of RNA without a capsid.
Siderophores are bacterial proteins that compete with the host's red blood cells. receptors. white blood cells. antibodies. iron-transport proteins.
iron-transport proteins.
Which of the following can be translated into protein? mRNA tRNA mRNA, tRNA, and rRNA are all translated into protein. rRNA
mRNA
Repair of damaged DNA might be viewed as a race between an endonuclease and primase. DNA polymerase. helicase. DNA ligase. methylase.
methylase
Which of the following is an antiprotozoan drug that interferes with anaerobic metabolism? erythromycin metronidazole acyclovir chloroquine
metronidazole
Which of the following is used to treat candidiasis of the skin or mucous membranes? trifluridine sulfonamide penicillin acyclovir miconazole
miconazole
The major significance of Robert Koch's work is that microorganisms cause disease. microorganisms are present in a diseased animal. microorganisms can be cultured. microorganisms are the result of disease. diseases can be transmitted from one animal to another.
microorganisms cause disease.
Which process is best for the short-term storage of bacterial cultures? deep-freezing refrigeration freeze-drying lyophilization
refrigeration
An envelope is acquired during which of the following steps? biosynthesis adsorption uncoating penetration release
release
Enveloped viruses have a layer of lipids surrounding their capsid. This envelope is made mostly of host cell membrane. In which step does the virus acquire this envelope? synthesis release assembly attachment
release
Which of the following cytopathic effects is cytocidal? transformation giant cells inclusion bodies release of enzymes from lysosomes antigenic changes
release of enzymes from lysosomes
Which of the following tends to be more complex in a parasitic helminth than in free-living helminths? digestive system nervous system reproductive system digestive and nervous systems digestive, reproductive, and nervous systems
reproductive system
Rickettsias differ from chlamydias in that rickettsias are gram-negative. are enterics. form elementary bodies. require an arthropod for transmission. are intracellular parasites.
require an arthropod for transmission.
Which of the following is NOT a characteristic of Neisseria? gram-negative cocci oxidase-positive requires X and V factors Some species are human pathogens.
requires X and V factors
Hepatitis B virus surface antigen can be used in a(n) inactivated whole-agent vaccine. attenuated whole-agent vaccine. conjugated vaccine. subunit vaccine. toxoid vaccine.
subunit vaccine.
Purified protein from Bordetella pertussis is used in a(n) subunit vaccine. toxoid vaccine. conjugated vaccine. nucleic acid vaccine. attenuated whole-agent vaccine.
subunit vaccine.
A person who attended a picnic early in the day develops a very high fever and is unresponsive by the evening. This person most likely has been exposed to a(n) superantigen. membrane disrupting toxin. enterotoxin. cytotoxin.
superantigen.
Symptoms of intense inflammation and shock occur in some gram-positive bacterial infections due to superantigens. erythrogenic toxin. lipid A. membrane-disrupting toxins. A-B toxins.
superantigens.
Bone and tendons for transplant are decontaminated by ethylene oxide. peroxygens. glutaraldehyde. supercritical fluids. plasma sterilization.
supercritical fluids.
Measles viruses are capable of inactivating host defenses by destroying complement proteins. producing superantigens. suppressing the immune system. producing leukocidins.
suppressing the immune system.
Consider a Kirby-Bauer disk-diffusion assay. If you put penicillin and streptomycin disks adjacent to one another, the zone of inhibition is greater than that obtained by either disk alone. This is an example of __________. mutual exclusion antagonism RNA interference synergism
synergism
Which one of the following steps does NOT occur during multiplication of a picornavirus? synthesis of viral proteins synthesis of + strands of RNA synthesis of - strands of RNA synthesis of DNA None of the answers is correct.
synthesis of DNA
The following steps occur during multiplication of retroviruses. Which is the fourth step? synthesis of +RNA penetration attachment uncoating synthesis of double-stranded DNA
synthesis of double-stranded DNA
Which of the following would be the first step in biosynthesis of a virus with a - (minus) strand of RNA? transcription of mRNA from DNA synthesis of DNA from a DNA template synthesis of DNA from an RNA template synthesis of double-stranded RNA from a DNA template synthesis of double-stranded RNA from an RNA template
synthesis of double-stranded RNA from an RNA template
Which of the following is involved in bringing amino acids to the ribosomes? tRNA rRNA mRNA, tRNA, and rRNA are all involved in transporting amino acids to the ribosomes. mRNA
tRNA
Which of the following is NOT a communicable diseases? AIDS typhoid fever tetanus tuberculosis malaria
tetanus
The antimicrobial drugs with the broadest spectrum of activity are aminoglycosides. tetracyclines. penicillin G. chloramphenicol. macrolides.
tetracyclines.
When a transducing phage interacts with a new host cell, it will cause the new cell to produce more transducing phage. the DNA from the previous host can recombine with the new host chromosome. the new host cell will be lysed.
the DNA from the previous host can recombine with the new host chromosome.
Injectable drugs are tested for endotoxins by filtering out the cells. looking for turbidity. counting the viable bacteria. culturing bacteria. the Limulus amoebocyte lysate test.
the Limulus amoebocyte lysate test.
Use of antibiotics in animal feed leads to antibiotic-resistant bacteria because the few surviving bacteria that are affected by the antibiotics develop immunity to the antibiotics, which they pass on to their progeny. bacteria from other animals replace those killed by the antibiotics. the antibiotics cause new mutations to occur in the surviving bacteria, which results in resistance to antibiotics. the antibiotics persist in soil and water. the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal.
the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal.
Antibodies from cellular immune responses are used in the lectin pathway. the alternative pathway. the classical pathway. both the classical and alternative pathways.
the classical pathway.
A persistent infection is one in which the virus remains in equilibrium with the host without causing a disease. host cells are transformed. the disease process occurs gradually over a long period. viral replication is unusually slow. host cells are gradually lysed.
the disease process occurs gradually over a long period.
Inactivated tetanus toxin is a(n) conjugated vaccine. subunit vaccine. nucleic acid vaccine. inactivated whole-agent vaccine. toxoid vaccine.
toxoid vaccine.
The antibiotic actinomycin D binds between adjacent G-C pairs, thus interfering with translation. plasma membrane function. cellular respiration. transcription. peptide bond formation.
transcription
Nonpathogenic Vibrio cholerae can acquire the cholera toxin gene by infecting a pathogenic Vibrio cholerae. phagocytosis. transduction. conjugation. transformation.
transduction
The process of acquiring antibiotic resistance by means of bacteriophage activity is called transduction. R-plasmid acquisition. point mutation. transformation.
transduction.
Conjugation differs from reproduction because conjugation replicates DNA. transfers DNA horizontally, to cells in the same generation. transcribes DNA to RNA. transfers DNA vertically, to new cells. copies RNA to make DNA.
transfers DNA horizontally, to cells in the same generation.
All of the following are considered examples of type I hypersensitivity EXCEPT pollen allergies. transplant rejections. penicillin allergic reactions. asthma. dust allergies.
transplant rejections.
An enzyme that catalyzes the cutting and resealing of DNA, and is translated from insertion sequences, is RNA polymerase. transposase. DNA ligase. DNA helicase. DNA polymerase.
transposase.
The function of the "ciliary escalator" is to remove microorganisms from the gastrointestinal tract. remove microorganisms from the upper respiratory tract. remove microorganisms from the lower respiratory tract. propel inhaled dust and microorganisms toward the throat. trap inhaled dust and microorganisms in mucous and propel it away from the lower respiratory tract.
trap inhaled dust and microorganisms in mucous and propel it away from the lower respiratory tract.
Which cytokines are believed to contribute to autoimmune disease, such as rheumatoid arthritis? tumor necrosis factor (TNF) interferons chemokines hematopoietic cytokines
tumor necrosis factor (TNF)
DNA is constructed of a single strand of nucleotides with internal hydrogen bonding. two strands of nucleotides running antiparallel. two strands of identical nucleotides with hydrogen bonds between them. two complementary strands of nucleotides bonded AC and GT. None of the answers is correct.
two strands of nucleotides running antiparallel.
Which type of hypersensitivity is allergic contact dermatitis? type I reaction type IV reaction type II reaction type III reaction
type IV reaction
The following steps occur during multiplication of herpesviruses. Which is the third step? biosynthesis penetration release uncoating attachment
uncoating
In which of the following diseases can gender be considered a viable predisposing factor? tetanus urinary tract infections pneumonia salmonellosis anthrax
urinary tract infections
Protein synthesis in eukaryotes is similar to the process in prokaryotes in that both eukaryotes and prokaryotes use methionine as the start amino acid. use codons to determine polypeptide sequences. have introns. require snRNPS. have exons.
use codons to determine polypeptide sequences.
Which of the following conditions in humans is linked to bovine spongiform encephalopathy? Variant Creutzfeldt-Jakob disease Gerstmann-Straussler-Scheinker syndrome Fatal familial insomnia Kuru
Variant Creutzfeldt-Jakob disease
Large antibodies that agglutinate antigens are IgG. IgM. IgA. IgD. IgE.
IgM.
A new arrow labeled "lengthens" could be added between __________. "target DNA" → "DNA strands" "Taq polymerase" → "primers" "primers" → "DNA strands" "target DNA" → "primers"
"Taq polymerase" → "primers"
Which of the following can be used directly as messenger RNA? +RNA -RNA ssDNA
+RNA
Which virus employs the use of an RNA-dependent RNA polymerase? +RNA viruses ssDNA viruses Retroviruses dsDNA viruses
+RNA viruses
Tori, a 24-year-old graduate student, had been suffering from a respiratory infection for over a week. She went to the student health center, where the physician prescribed her a broad-spectrum antibiotic. By the end of her round of antibiotics, Tori was no longer suffering from respiratory complications, but she had noticed an increase in itchiness in her genital region. Within a few days, the itchiness was getting worse and was accompanied by a vaginal discharge that had a cheesy consistency and foul odor. Tori returned to the student health center to discuss her condition with the physician. A sample of her discharge was taken and sent to the laboratory for microscopy and plating.
...
The progression from initial HIV infection to AIDS (in the US) usually takes: 5 years 10 years 20 years
10 years
The following data were obtained from a broth dilution test. Concentration of Antibiotic X Growth Growth in Subculture 2 μg/ml + + 10 μg/ml - + 15 μg/ml - - 25 μg/ml - - In the table, the minimal inhibitory concentration of antibiotic X is 15 μg/ml. 2 μg/ml. 25 μg/ml. 10 μg/ml. The answer cannot be determined based on the information provided.
10 μg/ml.
At a minimum, the human immune system is capable of recognizing approximately how many different antigens? 1010 1015 1020 105 1025
1015
Which of the following would be considered a vector? Water containing bacteria from fecal matter A fly carrying disease from fecal matter to food Water droplets that come from a sneeze from an infected individual Saliva that is transmitted between individuals during kissing
A fly carrying disease from fecal matter to food
A rabbit was found to have Floppy Ear disease that causes long-ear infections, but its etiology (cause) is unknown. Unknown Microorganism X from the infected rabbit's right ear was successfully isolated and cultured on laboratory growth media. The ear of a healthy laboratory mouse was then inoculated with isolated microorganism, and after a period of time, no disease is observed. Which of the following statements BEST describe the conclusion(s) that can be drawn from this experiment? Select all that apply. A laboratory mouse might not be an appropriate, susceptible host; an experiment with a laboratory rabbit may be needed. Microorganism X is the etiologic agent for Floppy Ear disease since it caused infection in the diseased rabbit. Microorganism X might not be linked to Floppy Ear disease, since the inoculated mouse remained healthy. It is not possible to isolate and culture Microorganism X in the laboratory, since this microbe is found in nature. Microorganism X modified its cell wall structure while being cultured, and is no longer infectious to rabbits. Healthy laboratory organisms rarely show signs and symptoms of infection and disease.
A laboratory mouse might not be an appropriate, susceptible host; an experiment with a laboratory rabbit may be needed. Microorganism X might not be linked to Floppy Ear disease, since the inoculated mouse remained healthy.
Which of the following events occurs during transcription? Those segments of the RNA strand that do not actually code for the protein are removed. The message in mRNA is translated into a protein. A molecule of RNA is formed based on the sequence of nucleotides in DNA. A cap is added to the RNA molecule. mRNA binds to a ribosome in the cytoplasm.
A molecule of RNA is formed based on the sequence of nucleotides in DNA.
What results from the process of translation? tRNA Ribosomes mRNA A polypeptide
A polypeptide
Which of the following would be an example of disease transmission via INDIRECT contact? A student sneezes on her test booklet. The instructor grades it and catches her cold. A restaurant worker has diarrhea caused by Norovirus. He fails to wash his hands adequately before preparing the salad, and his customers get sick. Mr. Smith sneezes on an airplane, and the person sitting beside him catches his cold. A tick that is infected with Lyme disease bites a hiker, and the hiker gets Lyme disease.
A student sneezes on her test booklet. The instructor grades it and catches her cold.
Which of the following regarding antimicrobial control agents is false? Some agents are utilized as both an antiseptic and a disinfectant. Some agents kill by denaturing microbial cell proteins. Some agents affect microbial cell membranes by dissolving lipids. Contaminating organic debris such as blood or sputum will decrease effectiveness. A true antimicrobial control agent is equally effective against both bacteria and viruses.
A true antimicrobial control agent is equally effective against both bacteria and viruses.
Which of the following is NOT a membrane-disrupting toxin? streptolysin S hemolysin leukocidin A-B toxin streptolysin O
A-B toxin
All of the following are used by bacteria to attach to host cells EXCEPT capsules. ligands. A-B toxins. fimbriae. M protein.
A-B toxins.
Which of the following statements about algae is FALSE? All are unicellular. They use CO2 as their carbon source. Some are capable of sexual reproduction. They use light as their energy source. They produce oxygen from hydrolysis of water.
All are unicellular.
Which of these disinfectants acts by denaturing proteins? Alcohols Aldehydes Bisphenols Phenolics All of the above
All of the above
Which of the following is NOT a cytopathic effect (CPE) of viruses? the formation of a syncytium chromosomal changes in the host cell formation of inclusion bodies All of the above are possible CPE.
All of the above are possible CPE.
Which of the following processes CANNOT be used to insert foreign DNA into cells? Transformation Electroporation Protoplast fusion A gene gun All of the above can be used to insert foreign DNA into cells.
All of the above can be used to insert foreign DNA into cells.
Genetic change in bacteria can be brought about by mutation. transformation. transduction. conjugation. All of the answers are correct.
All of the answers are correct.
Which of the following can contribute to postoperative infections? errors in aseptic technique using syringes more than once antibiotic resistance normal microbiota on the operating room staff All of the answers are correct.
All of the answers are correct.
Which of the following is a possible outcome of an HIV infection? Virions may remain latent. There may be persistent yeast infections . Infection may initially be asymptomatic. The disease does not progress to AIDS. All of the answers are correct.
All of the answers are correct.
All of the following factors contribute to hospital-acquired infections EXCEPT bacteria may be present in commercial products such as mouthwash. invasive procedures can provide a portal of entry for bacteria. gram-negative bacteria are often resistant to disinfectants. some bacteria metabolize disinfectants. All of these factors may contribute to hospital-acquired infection.
All of these factors may contribute to hospital-acquired infection.
Which of the following statements concerning transcription is true? During transcription, entire chromosomes are copied because the starting position of genes is unknown. All types of RNA in the cell are synthesized by transcription, which uses a portion of DNA as a template for copying. Transcription is the process whereby identical copies of DNA are made in preparation for cell division. Promoter sequences signal the end of a gene and mark the place where transcription stops.
All types of RNA in the cell are synthesized by transcription, which uses a portion of DNA as a template for copying.
Which of the complement pathways employs properdin? Classical pathway Alternative pathway Lectin pathway Alternative and lectin pathways all employ properdin. Classical, alternative, and lectin pathways all employ properdin. The classical and alternative pathways both require properdin.
Alternative pathway
Scientists like to use fluorescent proteins for various types of recombinant DNA procedures. You have a very small amount of the gene for a fluorescent protein. You'd like to make a fluorescent bacterium (!). Which of the following represents the correct sequence of procedures that you would use? Insert the gene into a plasmid vector. Amplify the gene using PCR. Transform the vector into the bacteria. Amplify the gene using PCR. Transform the vector into the bacteria. Insert the gene into a plasmid vector. Amplify the gene using PCR. Insert the gene into a plasmid vector. Transform the vector into the bacteria. Transform the vector into the bacteria. Amplify the gene using PCR. Insert the gene into a plasmid vector.
Amplify the gene using PCR. Insert the gene into a plasmid vector. Transform the vector into the bacteria.
What is meant by the clonal expansion of a B cell? An activated B cell divides into cells that give rise to memory B cells and plasma cells. An activated B cell will kill infected host cells. An activated B cell will immediately begin to produce antibodies. An activated B cell will engulf and digest anything foreign.
An activated B cell divides into cells that give rise to memory B cells and plasma cells.
Identify the statements below that accurately describe the mechanisms through which organisms acquire antibiotic resistance. Select all of the statements that accurately describe the origins and spread of antibiotic resistance. Antibiotics cause an increase in the rate of horizontal gene transfer. Antibiotic-resistance genes can be passed horizontally via bacterial conjugation. Antibiotic-resistance genes can be passed from one bacterium to another by bacterial transformation. Mutations are the ultimate source of antibiotic-resistance genes. Antibiotics cause mutations; heavy antibiotic use directly leads to mutations in microbes, giving rise to antibiotic resistance. Antibiotics select for those microbes that have developed resistance, increasing their frequency in the bacterial population. Antibiotic-resistance genes can be passed horizontally via transduction. Antibiotic resistance is readily transmitted to the next generation during binary fission.
Antibiotic-resistance genes can be passed horizontally via bacterial conjugation. Antibiotic-resistance genes can be passed from one bacterium to another by bacterial transformation. Mutations are the ultimate source of antibiotic-resistance genes. Antibiotics select for those microbes that have developed resistance, increasing their frequency in the bacterial population. Antibiotic-resistance genes can be passed horizontally via transduction. Antibiotic resistance is readily transmitted to the next generation during binary fission.
How might a patient who is not being treated with an antibiotic still be exposed to an antibiotic? Health care workers being treated with antibiotics may pass the antibiotic on to the patient. Antibiotics can be used in aerosols, thereby entering the environment. Visitors currently being treated with antibiotics can pass them on to the patient.
Antibiotics can be used in aerosols, thereby entering the environment.
A response that is uniquely directed against pathogenic Bordetella pertussis would involve what component? Antibodies Skin barrier The complement system Inflammation
Antibodies
Which of the following describes a cytotoxic autoimmune reaction? Cells are killed. Antibodies are not made. Mediate by T cells. Immune complexes form. Antibodies react to cell-surface antigens.
Antibodies react to cell-surface antigens.
Which phylum of protozoa contains organisms that are nonmotile obligate intracellular parasites? (Hint: They cause a well-known tropical disease.) Euglenozoa Apicomplexa Amoebozoa ciliates
Apicomplexa
Which of the following statements concerning sugar utilization in E. coli is true? Bacteria growing on glucose as the sole carbon source grow faster than on lactose. During the lag time between glucose and lactose consumption, intracellular cAMP decreases. Bacteria growing in a medium containing glucose and lactose first consume the lactose. When glucose is available, the level of cAMP in the E. coli is high.
Bacteria growing on glucose as the sole carbon source grow faster than on lactose.
Why is visualization not sufficient to properly identify bacteria? Bacteria have a limited set of shapes and many unrelated bacteria share the same shape. Many unrelated bacteria can share the same shape. Bacteria have a limited set of shapes. Not all bacteria can be seen with a light microscope. Identification is only needed in clinical specimens.
Bacteria have a limited set of shapes and many unrelated bacteria share the same shape.
Disease research and epidemiology bring together many different facets to help us better understand disease pathology and spread. Which of the following statements are true? Select all that apply. Bacterial exotoxins can be altered to create toxoids, which can be used to produce protective immunity in a host. Intoxications result from a bacterial infection in which a large amount of bacterial toxin is produced. The interactions that occur between a microbe and host influence the evolution of both. The terms pathogenicity and virulence can be used interchangeably to describe the severity of an infection. The ID50 value refers to the number of microbes needed to cause half of an infected population to die. Some pathogens are able to cause disease within a host without penetrating the body.
Bacterial exotoxins can be altered to create toxoids, which can be used to produce protective immunity in a host. The interactions that occur between a microbe and host influence the evolution of both.
Which of the following genera is an anaerobic gram-negative rod? Neisseria Escherichia Bacteroides Treponema Staphylococcus
Bacteroides
Which of the following might result in a frameshift mutation? Nitrous acid 5-bromouracil Benzopyrene
Benzopyrene
What is the function of the CD8 receptor? Activate cytokines Produce gamma interferon Produce IL-2 Bind to MHC molecules
Bind to MHC molecules
The host DNA is usually degraded during which stage? Penetration Attachment Assembly Release Biosynthesis
Biosynthesis
Above images are scanning electron micrographs of C. albicans. In these images, you can see that the cells are producing asexual spores called blastoconidia and chlamydoconidia. Second image above also shows the presence of pseudohyphae. Part F How do blastoconidia and chlamydoconidia produced by yeast differ from bacterial endospores? Blastoconidida and chlamydoconidia are identical to endospores. Blastoconidia and chlamydoconidia are spore structures produced by budding in yeasts, whereas bacterial endospores are produced by bacteria under extreme conditions. Blastoconidia and chlamydoconidia are produced only by yeasts in extreme conditions, whereas bacterial endospores are asexual reproductive structures. Blastoconidia and chlamydoconidia are male and female mating structures used for reproduction in yeasts, whereas bacterial endospores are asexual reproductive structures.
Blastoconidia and chlamydoconidia are spore structures produced by budding in yeasts, whereas bacterial endospores are produced by bacteria under extreme conditions.
What is the function of boosters? Boosters are vaccines containing no pathogenic portions of the pathogen. Boosters are the highly antigenic portions of the conjugated vaccines. Boosters help to kill the pathogens used in inactivated killed vaccines. Boosters are injections that are given periodically to maintain immunity.
Boosters are injections that are given periodically to maintain immunity.
In what way are semisynthetic penicillins and natural penicillins alike? Both are resistant to stomach acids. Both are resistant to penicillinase. Both are bactericidal. Both are based on β-lactam. Both are broad spectrum.
Both are based on β-lactam.
Which of the following criteria is most useful in determining whether two organisms are related? Both ferment lactose. Both are gram-positive. Both are aerobic. Both are motile. Each answer is equally important.
Both are gram-positive.
Which of the following characteristics indicates that two organisms are closely related? Both of their DNA can hybridize. Both are motile. Both ferment lactose. Both are cocci. Both normally live in clams.
Both of their DNA can hybridize.
Regarding the order Rhizobiales of the class Alphaproteobacteria, which genus includes human pathogens? Bradyrhizobium Agrobacterium Brucella Beijerinckia
Brucella
A disk-diffusion test using Staphylococcus gave the following results: Disinfectant Zone of inhibition (mm) A 0 B 2.5 C 10 D 5 In the table, which compound was the most effective against Staphylococcus? A B C D The answer cannot be determined.
C
Which of the following would you likely see on the surface of a human dendritic cell following phagocytosis of a bacterium? Class II MHC with engulfed bacterial antigens Class I MHC with dendritic cell antigens and Class II MHC with engulfed bacteria Class I MHC with dendritic cell antigens Class II MHC with dendritic cell antigens
Class I MHC with dendritic cell antigens and Class II MHC with engulfed bacteria
What would a virally infected skin epithelial cell have on its cell surface? Class I MHC with skin cell antigens Class II MHC with viral antigens Class II MHC with macrophage antigens Class II MHC with liver cell antigens
Class I MHC with skin cell antigens
A person who has AIDS contracts rare and often life-threatening infections because their helper T cell count is so low. Which of the following components of the immune response still respond to antigen despite the low helper T cell count? Clonal selection of B cells Apoptosis of infected host cells Clonal expansion and antibody production Activation of cytotoxic T cells
Clonal selection of B cells
All of the following bacteria release endotoxin EXCEPT Salmonella typhi. Neisseria meningitidis. Haemophilus influenzae. Proteus vulgaris. Clostridium botulinum.
Clostridium botulinum.
Which of the following statements is FALSE? Coagulase destroys blood clots. Hyaluronidase breaks down substances between cells. Leukocidins destroy neutrophils. Kinase destroys fibrin clots. Hemolysins lyse red blood cells.
Coagulase destroys blood clots.
Bacterial conjugation is often referred to as bacterial sex. Why is this term inaccurate? Bacteria are neither male nor female. Sex is a phenomenon only seen in animals. Conjugation does not result in the formation of new offspring. It does not require two cells to occur.
Conjugation does not result in the formation of new offspring.
Which statement about conjugation is false? E. coli is the model for bacterial conjugation. Conjugation is a process of bacterial reproduction. After conjugation, each cell involved has a copy of the shared DNA.
Conjugation is a process of bacterial reproduction.
Which of the following is considered a major category of transmission of disease? Contact, vehicle, and vector transmission Contact transmission Vector transmission Vehicle transmission
Contact, vehicle, and vector transmission
During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years. The etiologic agent of the disease in the situation is wind. pneumonia. Coxiella burnetii. soil. sheep.
Coxiella burnetii.
You see acid-fast oocysts in a fecal sample from a patient who has diarrhea. What is the MOST likely cause? Entamoeba Cryptosporidium Giardia Taenia diatoms
Cryptosporidium
If a person could not form C2, which result of complement would be affected? Opsonization Cytolysis Chemotaxis and inflammation Cytolysis, chemotaxis, inflammation, and opsonization
Cytolysis, chemotaxis, inflammation, and opsonization
Which cells directly attack abnormal cells in the body? Cytotoxic T cells B cells Helper T cells Phagocytes
Cytotoxic T cells
Which type of cell directly attacks infected cells? Helper T-cells Cytotoxic T-cells Cancerous cells Bacterial cells
Cytotoxic T-cells
HIV directly infects T-cells. Why is this problematic for cell-mediated immunity? Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body. HIV causes cytokines to be produced at much higher levels, altering the normal function of the immune system. HIV transforms the T-cells into cancer cells. HIV reprograms these cells to attack the body cells.
Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body.
Which one of the following does not play a role in translation? Anticodon DNA Amino acids Ribosomes tRNA
DNA
Which of the following methods could be used to identify the source of an outbreak? DNA fingerprinting artificial selection production of a recombinant protein reverse genetics
DNA fingerprinting
Quinolones and fluoroquinolones act against what bacterial target? Cell walls Cell membranes DNA gyrase Metabolic pathways unique to bacteria Bacterial ribosomes
DNA gyrase
An enzyme that makes covalent bonds between nucleotide sequences in DNA is DNA polymerase. DNA helicase. RNA polymerase. transposase. DNA ligase
DNA ligase
Which of the following attaches the target gene to a desired location? DNA ligase Plasmids Restriction enzymes Chromosomal DNA
DNA ligase
Generally, in an infection caused by a DNA-containing virus, the host animal cell supplies all of the following EXCEPT nucleotides. DNA polymerase. tRNA. RNA polymerase. None of the answers are correct; all of these are supplied by the host animal cell.
DNA polymerase.
What might interfere specifically with chemotaxis of a phagocyte? Think about the process of chemotaxis and what might compromise this process. Select each of the items that might specifically interfere with chemotaxis. Defective microfilament function Lysosomal defects Weak or inadequate flagellar movement Defective antibody production Absence of cytokine and complement receptors on phagocyte surfaces
Defective microfilament function Absence of cytokine and complement receptors on phagocyte surfaces
Impaired phagocytosis can lead to several disorders. This activity asks you to think specifically about the process through which phagocytes kill and digest microbes and to identify steps of the process that might be compromised and interfere with this killing activity. Select each of the items that would be likely to interfere with the killing of microbes once phagocytes have ingested them. Assume that chemotaxis, attachment, and ingestion occurred normally. Defective oxidative burst Defective microtubule function Ineffective opsonization Lack of chemotactic receptors on phagocytes Myeloperoxidase deficiency An increase in the number of leukocytes
Defective oxidative burst Defective microtubule function Myeloperoxidase deficiency
What provides the energy for DNA polymerization in a PCR reaction? Template DNA Primers Deoxyribonucleoside triphosphates DNA polymerase
Deoxyribonucleoside triphosphates
The following are steps used to make DNA fingerprints. What is the third step? Perform electrophoresis. Lyse cells. Collect DNA. Add stain. Digest with a restriction enzyme.
Digest with a restriction enzyme.
Which of the following is true regarding cultivation and isolation of animal viruses? The preferred and widely used method of viral isolation and growth is via growth in an embryonated egg. Mouse models are available for virtually all human viral infections and can be routinely used for vaccine development. Diploid cell culture lines, developed from human embryos, are widely used for culturing viruses that require a human host. Viruses can be easily grown in liquid culture without any other organisms present.
Diploid cell culture lines, developed from human embryos, are widely used for culturing viruses that require a human host.
Which of the following is NOT a step in bacterial cell division? Splitting apart of two new daughter cells Disappearance of nuclear envelope Replication of the genetic material Cell elongation
Disappearance of nuclear envelope
All of the following lead to drug-induced thrombocytopenic purpura. Which occurs first? Antibodies and complement react with platelets. Antibodies against haptens are formed. Purpura occurs on the skin. Platelets are destroyed. Drug binds to platelets.
Drug binds to platelets.
Which statement regarding the infectiveness and pathogenicity of HIV is FALSE? The ability of the HIV to remain as a provirus shelters it from the immune system. Some cells that do not carry the CD4 molecule can become infected with HIV. Attachment of HIV to the target cell depends on the glycoprotein spike (gp120) combining with the CD4+ receptor. During latent infections, the provirus directs the synthesis of many new viruses.
During latent infections, the provirus directs the synthesis of many new viruses.
Which of the following is true concerning a lysogenic viral replication cycle? During lysogeny, the viral DNA is present as a circular plasmid. Once the lysogenic portion of the cycle has begun, virus is never produced again. Lysogenic infections are similar to persistent infections, in that virus is constantly produced. During lysogeny, the viral genome integrates into the host DNA, becoming a physical part of the chromosome.
During lysogeny, the viral genome integrates into the host DNA, becoming a physical part of the chromosome.
When does MHC-II loading occur? During phagocytosis of an invading pathogen During viral infection After passing through the endoplasmic reticulum During the fusion of vesicles containing MHC-II proteins with vesicles containing digested pathogens
During the fusion of vesicles containing MHC-II proteins with vesicles containing digested pathogens
Which of the following is an example of the symbiotic relationship known as mutualism? Corynebacterium on the surface of the eye saprophytic Mycobacterium of the ear E. coli within the large intestine a tapeworm in the gastrointestinal tract of a human
E. coli within the large intestine
What makes agglutination by antibodies possible? Antibodies can inactivate toxins. Antibodies can recognize bacteria as well as viruses. Antibodies are produced by plasma cells. Each antibody has at least two antigen-binding sites.
Each antibody has at least two antigen-binding sites.
Which biologist introduced the term prokaryote in 1937 to distinguish cells with no nucleus from the nucleated cells of plants and animals? Robert H. Whittaker Edouard Chatton Carl Woese Carl von Nägeli
Edouard Chatton
Membrane transport proteins are required for which mode(s) of antibiotic resistance? Modification of a porins Beta-lactamases Efflux pumps Efflux pumps, beta-lactamases, and modification of porins all utilize membrane transport proteins. Modification of a metabolic enzyme
Efflux pumps, beta-lactamases, and modification of porins all utilize membrane transport proteins.
The brain tissue of the birds indicated the possibility of encephalitis. What is encephalitis, and why should this type of infection cause concern among health care professionals? Encephalitis is an inflammation of the meninges. It is a concern to health care professionals because of how quickly the infection will spread to the rest of the body. Encephalitis is an inflammation of the peripheral nervous system. It is a concern to health care professionals because of how quickly the infection will spread to the rest of the body. Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures. Encephalitis is an inflammation of the spinal cord. It is a concern to health care professionals because the infection will spread to the brain.
Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures.
In immune complex reaction shown in the figure, what is the end result of the reaction? IgG is directed against cell membrane antigens. Complement is activated. Endothelial cells are damaged. Antibodies destroy neutrophils. Neutrophils are attracted and release enzymes.
Endothelial cells are damaged.
Which gammaproteobacteria are facultatively anaerobic, gram-negative rods that inhabit the intestinal tracts of humans and other animals? Pseudomonadales Legionellales Enterobacteriales Vibrionales
Enterobacteriales
Which type of virus would produce viral glycoproteins to be expressed on the host cell membrane? +RNA viruses dsRNA viruses Enveloped viruses Naked viruses
Enveloped viruses
Which one of the following bacteria does NOT belong with the others? Streptococcus Bacillus Staphylococcus Lactobacillus Escherichia
Escherichia
Which of the following phagocytic processes occurs last in the sequence? Exocytosis Formation of the phagolysosome Adherence Chemotaxis of the phagocyte to the site of infection
Exocytosis
Which of the following statements about lysogenic conversion is true? Lysogenic bacteria are always less virulent than nonlysogenic bacteria because the viral infection weakens them. Exotoxin production by bacteria is frequently the result of a lysogenic infection. Lysogenic conversion is a result of the transfer of plasmids from one bacterium to another. Endotoxin production by bacteria is frequently the result of a lysogenic infection.
Exotoxin production by bacteria is frequently the result of a lysogenic infection.
Which of the following events might trigger induction of a temperate bacteriophage? Exposure to UV light An infected cell entering the logarithmic phase of growth Normal cell division of an infected cell Bacterial conjugation
Exposure to UV light
How does cytolysis occur via the complement pathway? Formation of the MAC in invading cells, killing them Disrupting cell wall of pathogens Stimulation of the inflammatory response Triggering the release of histamine
Formation of the MAC in invading cells, killing them
If you begin with six cells, how many cells would you have after three rounds of division? Twelve cells Nine cells Eighteen cells Twenty-four cells Forty-eight cells It is impossible to determine.
Forty-eight cells
Which of the following statements is true regarding hand washing? Hand washing should be done frequently by healthcare workers. Hand washing should be done frequently by patients. Hand washing should be done before and after patient interaction. Frequent and proper hand washing should be routinely done by patients and by healthcare workers, both prior to and after interaction.
Frequent and proper hand washing should be routinely done by patients and by healthcare workers, both prior to and after interaction.
Which of the following statements best describes why the treatment for Tori's fungal infection may result in side effects to her own cells? Fungal cells and human cells have a nucleus, multiple organelles, and 80S ribosomes for protein synthesis. Fungal cells and human host cells both have flagella for movement. Fungal cells and human host cells both have cell walls made of cellulose. Fungal cells and human cells both reproduce via budding.
Fungal cells and human cells have a nucleus, multiple organelles, and 80S ribosomes for protein synthesis.
Which of the following is a DNA strand complementary to CGA ATC AGC? GCU UAG UCG GCT TAG TCG TAG GCT GAT CGA ATC AGC
GCT TAG TCG
Which of the following statements is TRUE? Alpha interferon promotes phagocytosis. Gamma interferon causes bactericidal activity by macrophages. Alpha interferon acts against specific viruses. All three types of interferons have the same effect on the body. Beta interferon attacks invading viruses.
Gamma interferon causes bactericidal activity by macrophages.
How is generalized transduction different from specialized transduction? Specialized transduction uses animal viruses instead of bacteriophage. Only one specific host gene is transferred in both specialized transduction and generalized transduction. Generalized transduction is initiated during lytic cycle of a virulent bacteriophage; specialized transduction is initiated during the lysogenic cycle of a temperate bacteriophage. Generalized transduction is initiated by a lysogenic bacteriophage; specialized transduction is initiated by a lytic phage.
Generalized transduction is initiated during lytic cycle of a virulent bacteriophage; specialized transduction is initiated during the lysogenic cycle of a temperate bacteriophage.
What does the plasma membrane of a phagocyte attach to on a microorganism? Phagosomes Lysosomes Pseudopods Glycoproteins
Glycoproteins
The first question in this dichotomous key addresses metabolic characteristics. oxygen tolerance. bacterial morphology. Gram stain differences.
Gram stain differences.
You have isolated a prokaryotic cell. The first step in identification is a(n) lactose fermentation test. DNA fingerprint. endospore stain. flagella stain. Gram stain.
Gram stain.
The presence of which of the following indicates a current infection rather than a previous infection or vaccination? IgM IgD IgG IgE IgA
IgM
In addition to IgG, the antibodies that can fix complement are IgD. None of the answers is correct. IgE. IgM. IgA.
IgM.
Which molecule triggers apoptosis? Granzyme Gamma-interferon IL-2 MHC Perforin
Granzyme
Frederick Griffith did experiments on genetic transformation. Which of the following statements about his experiments is accurate? The combination of living nonencapsulated bacteria and heat-killed encapsulated bacteria did not cause disease. Griffith used only pathogenic bacteria in his experiments. Griffith used bacteria in which the nonpathogenic strain was encapsulated but the pathogenic strain was not. Griffith found that DNA released from dead (virulent) bacteria entered live (avirulent) bacteria and changed them genetically, causing them to become virulent.
Griffith found that DNA released from dead (virulent) bacteria entered live (avirulent) bacteria and changed them genetically, causing them to become virulent.
All of the following protect the skin and mucous membranes from infection EXCEPT the "ciliary escalator." multiple layers of cells. saliva. HCl. tears.
HCl.
Which of the following are used to determine relatedness between a donor and a recipient for transplants? HLA antigens. ABO blood group antigens. MHC antigens. HLA and MHC antigens. HLA, MHC, and ABO blood group antigens.
HLA, MHC, and ABO blood group antigens.
If a patient is diagnosed with a peptic ulcer, which genus of Proteobacteria is probably responsible? Helicobacter Campylobacter Desulfovibrio Myxococcus
Helicobacter
Which statement regarding helminths is true? The life cycle of helminths is always very simple, and they usually infect only one host. They are unicellular. Helminths usually possess specialized organ systems, including circulatory, nervous, and reproductive systems. They are always dioecious, which means that one individual has both male and female reproductive organs.
Helminths usually possess specialized organ systems, including circulatory, nervous, and reproductive systems.
What is the role of helper T cells in the adaptive immune response? Helper T cells phagocytize bacteria and viruses. Helper T cells produce and secrete antibodies. Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells. Helper T cells directly kill infected host cells.
Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells.
Cytokines are produced by which of the following cells? Virally infected cells Abnormal body cells Invading pathogenic bacteria Cytotoxic T-cells Helper T-cells
Helper T-cells
How do helper T-cells and cytotoxic T-cells work together? Helper T-cells produce cytotoxic T-cells. Helper T-cells produce cytokines to activate other cells of the immune system. Cytotoxic T-cells produce cytokines to activate helper T-cells. Cytotoxic T-cells attack abnormal body cells, while helper T-cells attack virally infected cells.
Helper T-cells produce cytokines to activate other cells of the immune system.
You are conducting a viral hemagglutination inhibition test. Which of the following indicates that a patient's serum has antibodies against influenza virus? Hemagglutination occurs in a mixture of influenza virus and erythrocytes but does not occur when the patient's serum is added. Hemagglutination occurs in a mixture of influenza virus and erythrocytes and also occurs when the patient's serum is added. Hemagglutination does not occur in a mixture of influenza virus and erythrocytes but does occur when the patient's serum is added. An antigen-antibody reaction will occur, resulting in precipitation.
Hemagglutination occurs in a mixture of influenza virus and erythrocytes but does not occur when the patient's serum is added.
Which of the following statements about type IV reactions is FALSE? Cytokines initiate tissue damage. Reactions are not apparent for a day or more. Reactions are primarily due to T cell proliferation. Allergic contact dermatitis is an example. Hemolytic disease of the newborn is an example.
Hemolytic disease of the newborn is an example.
Viruses that utilize reverse transcriptase belong to the virus families Hepadnaviridae and Retroviridae. Rhabdoviridae and Herpesviridae. Retroviridae and Picornaviridae. Herpesviridae and Retroviridae. Herpesviridae and Poxviridae.
Hepadnaviridae and Retroviridae.
DNA made from an RNA template will be incorporated into the virus capsid of Herpesviridae. influenzavirus. Retroviridae. Hepadnaviridae. bacteriophage families.
Hepadnaviridae.
Which of the following statements about biological transmission is FALSE? Houseflies are an important vector. The pathogen reproduces in the vector. The pathogen may enter the host in the vector's feces. The pathogen may require the vector as a host. The pathogen may be injected by the bite of the vector.
Houseflies are an important vector.
Why are chemotherapeutic agents that work on the peptidoglycan cell wall of bacteria a good choice of drug? Bacteria are especially sensitive to these compounds. The drugs also work against DNA gyrase. They are less expensive that other chemotherapeutic agents. Humans and other animal hosts lack peptidoglycan cell walls.
Humans and other animal hosts lack peptidoglycan cell walls.
Antibodies are a part of which type of immunity? Cell-mediated Humoral Neither humoral nor cell-mediated Both humoral and cell-mediated
Humoral
Which part of the adaptive immune response involves B cells? Neither humoral nor cell-mediated Both humoral and cell-mediated Cell-mediated Humoral
Humoral
Which of the following enzymes breaks down the "glue" that holds cells together? Fibrinolysin Streptokinase Hyaluronidase Collagenase
Hyaluronidase
The antibodies found in mucus, saliva, and tears are IgG. IgM. IgA. IgD. IgE.
IgA.
The antibodies found on the surface of B cells, and which always exist as monomers, are IgG. IgM. IgA. IgD. IgE.
IgD.
Which of the following mediators are involved in anaphylactic reactions? Select all that apply. IgM IgE T cells basophils B cells mast cells
IgE basophils mast cells
Anaphylaxis is the term for reactions caused when certain antigens combine with IgE antibodies. histamine. IgG antibodies. complement. macrophages.
IgE antibodies.
Which of the following is FALSE concerning type II (cytotoxic) hypersensitivity reactions? Macrophage activity my lead to additional cellular damage. IgE binds to mast cells or basophils. IgM and IgG antibodies bind to antigens on foreign cells. They are responsible for transfusion reactions.
IgE binds to mast cells or basophils.
The antibodies that can bind to large parasites are IgG. IgM. IgA. IgD. IgE.
IgE.
Which immunoglobulin class, found in blood, lymph, and the intestine, can cross the placenta and help to protect a fetus? IgM IgG IgE IgA
IgG
Which type of response does the process of desensitization produce? T-cell IgG IgE IgM
IgG
The most abundant class of antibodies in serum is IgG. IgM. IgA. IgD. IgE.
IgG.
If a patient has been exposed to an antigen for the first time, which class of immunoglobulin appears first? IgD IgM IgG IgE
IgM
Which of the following best describes graft-versus-host disease? Immune cells attack transplanted tissue in a privileged site. The cells of a host reject transplanted bone marrow. Immune cells in transplanted bone marrow attack the cells of the host. A tissue transplant is rejected because the host's T cytotoxic cells are activated and kill the transplanted tissue.
Immune cells in transplanted bone marrow attack the cells of the host.
Which of the following is a characteristic of rheumatoid arthritis? Antibodies attach to receptors on thyroid gland cells. Antibodies coat acetylcholine receptors at neuromuscular junctions. Immune complexes of IgM, IgG, and complement are involved. T cytotoxic cells attack joint tissue.
Immune complexes of IgM, IgG, and complement are involved.
Which operons are never transcribed unless activated? Inducible operons Repressible operons Inducible and repressible operons
Inducible operons
Which of the following is true concerning systemic anaphylaxis? Systemic anaphylaxis frequently occurs as a result of exposure to inhaled allergens. Injected antigens combine with IgE antibodies on the surface of certain cells, causing them to release histamines and other inflammatory mediators. Asthma is a type of systemic anaphylaxis. Anaphylactic shock results from an increase in blood pressure, which is caused by blood vessel constriction.
Injected antigens combine with IgE antibodies on the surface of certain cells, causing them to release histamines and other inflammatory mediators.
Which of the following statements about innate immunity is true? Innate immunity involves specific recognition of microorganisms via a memory response. The innate immune response does not have a mechanism for detecting invading microorganisms. It is activated only in response to tissue damage or a signal from an infected cell. It involves the activity of B and T cells. Innate immunity is present at birth.
Innate immunity is present at birth.
Which of the following statements is FALSE? Interferon inhibits glycolysis. Amantadine inhibits the release of viral nucleic acid. Acyclovir inhibits DNA synthesis. Fluoroquinolone inhibits DNA synthesis. Azoles inhibit plasma membrane synthesis.
Interferon inhibits glycolysis.
Why is vasodilation important to tissue repair? It allows for an increase in oxygen to the site of damage. It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage. It allows more phagocytes to travel to the site of damage. It allows more nutrients to be delivered to the site of damage.
It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage.
Why is polymyxin only used on the skin? It can disrupt the metabolic pathways found in humans. It can also damage living human cell membranes, but the drug is safely used on the skin, where the outer layers of cells are dead. It is sensitive to degradation by acid, making oral delivery unsuitable. It has no effect on bacteria that live in the GI tract.
It can also damage living human cell membranes, but the drug is safely used on the skin, where the outer layers of cells are dead.
Why would a recombinant DNA molecule be inserted into a host cell? Restriction enzymes can only be used inside of a cell. It can protect the recombinant DNA. It can be copied, transcribed, and translated into a desired protein. Plasmids cannot be isolated outside of a host cell.
It can be copied, transcribed, and translated into a desired protein.
Which of the following is NOT true of acne? Mild cases are treated with topical agents. It can be treated by eliminating fatty foods from the diet. It is often due to the action of Propionibacterium. Antibiotics may be prescribed for moderate cases. Drugs that inhibit sebum formation are useful in treating inflammatory acne.
It can be treated by eliminating fatty foods from the diet.
How does the protozoan Trypanosoma evade detection by the immune system? It can resist oxidation inside macrophages. It produces a capsule which is composed of polysaccharides similar to those found in the host. It prevents phagosome-lysosome fusion. It can change the surface antigens frequently, preventing the immune system from tracking it.
It can change the surface antigens frequently, preventing the immune system from tracking it.
Why is a release of endotoxin into the bloodstream potentially deadly? It causes necrosis of the liver. Endotoxin can quickly enter the brain from the bloodstream, causing brain damage. It results in dehydration of the patient. It can lower blood pressure and cause the patient to go into shock.
It can lower blood pressure and cause the patient to go into shock.
Which of the following describes how 5-bromouracil might create a mutation? It can replace the base thymine, and can base pair with guanine rather than adenine. It creates bulges in the DNA that must be repaired. It can form thymine dimers. It causes double-stranded breaks of the DNA.
It can replace the base thymine, and can base pair with guanine rather than adenine.
Why is DNA polymerase from Thermus aquaticus ideal for PCR? It can withstand the high temperatures associated with PCR. It does not require primers. It does not require energy to polymerize DNA. It can synthesize DNA 5' to 3' and 3' to 5'.
It can withstand the high temperatures associated with PCR.
Which organism in the table causes the most severe disease? Treponema pallidum Shigella E. coli O157:H7 Legionella pneumophila It cannot be determined from the information provided.
It cannot be determined from the information provided.
Which of the following is a limitation of the autoclave? It cannot be used with heat-labile materials. It requires an excessively long time to achieve sterilization. It cannot inactivate viruses. It cannot kill endospores. It cannot be used with glassware.
It cannot be used with heat-labile materials.
Which of the following statements about congenital rubella syndrome is FALSE? It can be prevented by vaccinating women prior to pregnancy. It is contracted during the first trimester of pregnancy. It may result in deafness, blindness, and mental retardation. It may be fatal to the unborn child. It does not occur with subclinical infections.
It does not occur with subclinical infections.
Why is the unknown in this example not Pseudomonas? It ferments lactose. It is a Gram-negative cell. It can tolerate oxygen. It is a rod-shaped cell.
It ferments lactose.
What cellular macromolecules make up the complement pathway? Nucleic acids Proteins Carbohydrates Lipids
Proteins
Trichomonas vaginalis can be distinguished from other parasitic protozoa by which of the characteristics listed below? It has an undulating membrane, infects the vagina, and is frequently transmitted by sexual contact. It infects Anopheles mosquitoes and can be transmitted by a bite. It is usually found in drinking water and is associated with fecal contamination. It is a photosynthetic organism that lives in fresh water.
It has an undulating membrane, infects the vagina, and is frequently transmitted by sexual contact.
Which of the following statements about recombinant DNA technology is FALSE? It allows researchers to make many copies of a gene of interest. It has limited application because genes of interest cannot be moved from one type of cell to another. It allows researchers to make protein products of a gene. It can be used to screen individuals for many different types of genetic diseases.
It has limited application because genes of interest cannot be moved from one type of cell to another.
What is the fate of the prophage during the lysogenic stage? It is packaged into viral proteins and maintained until the host is exposed to an environmental stress. It is copied every time the host DNA replicates. It is released from the cell by lysing the cell. It is degraded by the activity of host defense enzymes.
It is copied every time the host DNA replicates.
Which of the following statements about the causative agent of Rocky Mountain spotted fever is FALSE? It is an intracellular parasite. It is transmitted by ticks. It is found in soil and water. It is gram-negative. It is in the genus Rickettsia.
It is found in soil and water.
Which of the following statements about drug resistance is FALSE? It may be carried on a plasmid. It may be due to enzymes that degrade some antibiotics. It may be due to increased uptake of a drug. It is found only in gram-negative bacteria. It may be transferred from one bacterium to another during conjugation.
It is found only in gram-negative bacteria.
How does the malachite green stain enter an endospore? It is heated. It is mixed with the mordant tannic acid. It is mixed with hydrochloric acid. It is dissolved in alcohol.
It is heated.
Which of the following statements about staphylococcal enterotoxin is FALSE? It causes vomiting. It is produced by Staphylococcus aureus growing in the host's intestines. It causes diarrhea. It is an exotoxin. It is a superantigen.
It is produced by Staphylococcus aureus growing in the host's intestines.
Which of the following statements about M protein is FALSE? It is heat- and acid-resistant. It is a protein. It is found on fimbriae. It is found on Streptococcus pyogenes. It is readily digested by phagocytes.
It is readily digested by phagocytes.
Bacillus anthracis can cause infection via three different portals of entry. The ID50 of cutaneous anthrax is 10 to 50 endospores, while inhalation anthrax requires 10,000 to 20,000 endospores, and gastrointestinal anthrax requires 250,000 to 1,000,000 endospores. Which statement best describes a conclusion that can be drawn based on this information? Cutaneous anthrax is rarely observed when monitoring cases across the population. It is significantly easier to be infected with cutaneous anthrax as compared to other forms of anthrax. The portal of exit impacts the infectious dose needed to cause infection at the portal of entry. Equal numbers of cutaneous, inhalation, and gastrointestinal anthrax infections are observed in human hosts. Exposure to a small number of endospores (less than 1,000) is most likely to result in gastrointestinal anthrax.
It is significantly easier to be infected with cutaneous anthrax as compared to other forms of anthrax.
Which of the following WBCs are NOT lymphocytes? NK cells helper T cells B cells M cells cytotoxic T cells
M cells
Which of the following statements about Reye syndrome is FALSE? It is associated with aspirin use. Prolonged neurological problems may occur. Symptoms may include vomiting, drowsiness, or behavior changes. It mostly affects older adults. It is a complication that may occur in chickenpox infection.
It mostly affects older adults.
Why is methicillin-resistant Staphylococcus aureus (MRSA) methicillin resistant? It produces a modified version of the molecule that is targeted by the drug. The bacteria are able to prevent entry of the drug into the cell. It has an enzyme that destroys methicillin. It actively pumps the antibiotic out of the cell.
It produces a modified version of the molecule that is targeted by the drug.
What is the function of the parental DNA in replication? It is passed into the offspring of the parent. It gives the cell two complete copies of the DNA. It serves as the template for DNA replication. It allows for the DNA to be circular.
It serves as the template for DNA replication.
How would the results be different if this organism was Salmonella? It would produce hydrogen sulfide. It would be a rod. It would not ferment lactose. It would not tolerate oxygen
It would produce hydrogen sulfide.
In the last segment of the animation, when does the first epidemic occur? January of year four January of year three April of year four September of year three March of year two
January of year three
An inflammatory response would result from which of the following? Vomiting Jellyfish sting A headache
Jellyfish sting
Which of the following statements about fungi is true? Conidiospores are spores that are enclosed in a specialized sac-like structure. Most fungi reproduce only asexually. Karyogamy refers to a part of the sexual reproduction cycle in which two haploid nuclei fuse to form a diploid zygote. Fungi are usually identified using biochemical tests.
Karyogamy refers to a part of the sexual reproduction cycle in which two haploid nuclei fuse to form a diploid zygote.
________________ is/are always present in an individual's blood. However, in the absence of infection, it is in an inactive form. Kinins Cytokines Prostaglandins Histamine
Kinins
Which of the following prion diseases was also known as laughing disease? Bovine spongiform encephalopathy Gerstmann-Straussler-Scheinker syndrome Creutzfeldt-Jakob disease Kuru
Kuru
Gram-negative septic shock results from the following events. What is the second step? LPS is released from gram-negative bacteria. IL-1 is released. Fever occurs. Body temperature is reset in the hypothalamus. Phagocytes ingest gram-negative bacteria.
LPS is released from gram-negative bacteria.
Why might cells begin to die at a faster rate than new cells are made? Original cells get too old. Lack of nutrients Increase in cellular waste products Cells can only divide a certain number of times before they die. Lack of nutrients and an increase in cellular waste products.
Lack of nutrients and an increase in cellular waste products.
Which of the following statements regarding latent viral infections is true? Latent viral infections are caused by the slow conversion of cellular glycoproteins from normal to infectious form. Latent infections can persist for years in an individual without causing any symptoms. During latent infections, small amounts of virus are produced, and virus numbers build up over time. Latent viral infections are almost always fatal.
Latent infections can persist for years in an individual without causing any symptoms.
Bacterium ID50 E. coli O157:H7 20 Legionella pneumophila 1 Shigella 10 Treponema pallidum 57 Which organism in the table most easily causes an infection? Treponema pallidum Shigella Legionella pneumophila E. coli O157:H7 The answer cannot be determined based on the information provided.
Legionella pneumophila
Which of the following statements regarding lichens is FALSE? The algal partner produces carbohydrates that are absorbed by the fungal partner. The fungal partner provides a means of attachment and protects the algal partner from desiccation. Lichens are often the first life form to colonize rock or soil. Lichens represent a mutualistic relationship between a fungus and an alga. Lichens are very tolerant to pollution.
Lichens are very tolerant to pollution.
Which of the following repair mechanism(s) does not involve DNA polymerase? Light-repair mechanism Excision-repair mechanism Mismatch-repair mechanism
Light-repair mechanism
Which of the following is the best mode of controlling the spread of West Nile infections? Kill all mosquitoes to prevent the transmission of West Nile virus. Kill all birds to prevent the amplification and transmission of West Nile virus. Limit exposure to mosquitoes to prevent the transmission of West Nile virus. Limit exposure to birds to prevent the transmission of West Nile virus.
Limit exposure to mosquitoes to prevent the transmission of West Nile virus.
Endotoxins are also known as prostaglandins. interleukin-1. Lipid A. cytokines.
Lipid A.
You have isolated a gram-positive bacterium with low G + C content. It was a contaminant in unpasteurized milk. It infected a pregnant woman, and now you are worried that her child will be stillborn. What bacterium is it? Clostridium Listeria monocytogenes Mycobacterium Anabaena
Listeria monocytogenes
Which statement regarding the lymphatic system is true? The thymus serves as the site for activation of B cells. Lymphatic capillaries possess one-way valves. These valves permit the uptake of fluid from the body but do not allow the fluid to flow back out of the capillaries into the intracellular spaces. The pancreas contains lymphocytes and macrophages that monitor the blood for microbes. Lymph nodes are sites of activation of neutrophils, which destroy microbes.
Lymphatic capillaries possess one-way valves. These valves permit the uptake of fluid from the body but do not allow the fluid to flow back out of the capillaries into the intracellular spaces.
Where is the site of Shigella attachment in the host? Phagocytes M cells Intestinal epithelial cells Leukocytes
M cells
What is the outstanding characteristic of the Kingdom Fungi? All members are photosynthetic. Members absorb dissolved organic matter. Members absorb dissolved inorganic matter. All members are microscopic. All members are macroscopic.
Members absorb dissolved organic matter.
The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. What component of the immune system will protect her from getting the same cold again? Plasma cells Antibodies that are "left over" from the last infection Dendritic cells Memory B cells
Memory B cells
Which cells are involved in a secondary response? Memory B cells and plasma cells Memory B cells Plasma cells T cells
Memory B cells and plasma cells
When a person has previously been vaccinated against a viral pathogen, which cells are activated if that same pathogen re-enters the host's cells months or years later? Memory cytotoxic T cells Memory B cells Helper T cells Bacterial pathogens
Memory cytotoxic T cells
Which order or genus of Archaea are part of the microbiota of the human colon, vagina, and mouth? Pyrodictium Methanobacteriales Sulfolobales Halobacteriales
Methanobacteriales
Which of the following is an example of a dye used in a simple stain? Nigrosin Carbolfuchsin Eosin Methylene blue
Methylene blue
Consider the different mechanisms through which antibiotics inhibit microbial growth, and consider what changes in the microbe might enable it to resist the inhibitory effects of antibiotics. Select all of the statements that describe a mechanism that would enable a microorganism to resist the action of an antibiotic. Microbe develops transport mechanism in plasma membrane that rapidly pumps antibiotic out of the bacterial cell Production of an enzyme that destroys the antibiotic Modified target site, such that an antibiotic is unable to bind to its target Altered target that enhances the binding of antibiotic Development of a transport mechanism that rapidly transports antibiotic through the plasma membrane into the cytoplasm Altered porins in cell wall, which block passage of antibiotic through cell wall
Microbe develops transport mechanism in plasma membrane that rapidly pumps antibiotic out of the bacterial cell Production of an enzyme that destroys the antibiotic Modified target site, such that an antibiotic is unable to bind to its target Altered porins in cell wall, which block passage of antibiotic through cell wall
Think through the steps of phagocytosis, and select strategies from the list provided that might enable a microbe to avoid or escape phagocytosis or phagocytic killing. Select each of the items from the list that would enable a microbe to evade phagocytosis or avoid phagocytic killing. Microbe prevents fusion of phagosome with lysosome to form phagolysosome. Microbe escapes from phagosome prior to fusion with lysosome. Microbial cell wall contains an outer membrane of lipopolysaccharide. Microbe speeds up acidification of phagosome. Microbe produces leukocidin. Microbial cell wall contains peptidoglycan. A capsule surrounds the microbe.
Microbe prevents fusion of phagosome with lysosome to form phagolysosome. Microbe escapes from phagosome prior to fusion with lysosome. Microbe produces leukocidin. A capsule surrounds the microbe.
In the cladogram shown in the figure, which two organisms are most closely related? Mycobacterium and Lactobacillus Micrococcus and Mycobacterium Streptomyces and Micrococcus Streptomyces and Lactobacillus Streptomyces and Mycobacterium
Micrococcus and Mycobacterium
Which of the following cause(s) ringworm? Microsporum Epidermophyton Mycobacterium Microsporum and Epidermophyton Microsporum, Epidermophyton, and Mycobacterium
Microsporum and Epidermophyton
Which of the following repair enzymes cannot repair thymine dimers? Excision-repair enzymes Light-repair enzymes Mismatch-repair enzymes
Mismatch-repair enzymes
What are leukocidins? Molecules that destroy the complement proteins Molecules that can degrade IgA Molecules that are capable of destroying phagocytes
Molecules that are capable of destroying phagocytes
Which of the following statements about adherence is true? Most bacteria can adhere to any cell in the host. Adhesins are always located on the bacterium's cell membrane. The host cell receptors for bacterial adhesins are usually proteins. Most bacterial adhesins are glycoproteins or lipoproteins.
Most bacterial adhesins are glycoproteins or lipoproteins.
A patients serum, Mycobacterium, guinea pig complement, sheep red blood cells, and anti-sheep red blood cell antibodies are mixed in a test tube. What happens if the patient has antibodies to Mycobacterium? Bacteria fluoresce. Hemolysis occurs. Hemagglutination-inhibition occurs. Hemagglutination occurs. No hemolysis occurs.
No hemolysis occurs.
How long does it take for the daughter cells from one round of replication to replicate themselves? After the cells have matured fully. 20 minutes No time is needed -- the daughter cells cannot replicate further. No time is required -- they are ready to divide immediately after DNA replication and separation of the daughter cells is complete if conditions are right.
No time is required -- they are ready to divide immediately after DNA replication and separation of the daughter cells is complete if conditions are right.
While working with a broth culture of archaea in the laboratory, you accidentally spill some of the microorganisms on yourself. Do you need to be concerned about developing an infection? Why or why not? No; archaea are prokaryotic, so they cannot cause infection. Yes; certain archaea can be pathogenic, so an infection could occur. No; archaea are not pathogenic. Yes; all infectious prokaryotes are archaea.
No; archaea are not pathogenic.
Why would a body cell that is not a phagocyte need to present antigens? Non-phagocytic body cells can become infected with a virus. Antigens are infectious and can spread to normal cells. Antigens are required for cell-to-cell attachment. All cells of the body can engulf invading cells.
Non-phagocytic body cells can become infected with a virus.
Which of the following is NOT a predisposing factor of disease? lifestyle None of the answers are correct; all of these are predisposing factors of disease. genetic background occupation climate
None of the answers are correct; all of these are predisposing factors of disease.
Which one of the following is NOT a zoonosis? tapeworm Hantavirus pulmonary syndrome cat-scratch disease rabies None of the answers is correct; all of these are zoonoses.
None of the answers is correct; all of these are zoonoses.
Which of the following is NOT a reservoir of infection? a healthy person a hospital a sick animal a sick person None of the answers is correct; all of these can be reservoirs of infection.
None of the answers is correct; all of these can be reservoirs of infection.
Which of the following pairs is mismatched? influenza - droplet infection syphilis - direct contact malaria - vector salmonellosis - vehicle transmission None of the pairs is mismatched.
None of the pairs is mismatched.
How do normal prion proteins (PrP) differ from the infectious prion proteins? Normal PrP are found on mammals; infectious PrP are found on reptiles. Normal PrP are found in all mammals; infectious PrP are found in only cows. Normal PrP lack nucleic acid; infectious PrP have nucleic acid. Normal PrP have alpha-helices; infectious PrP have beta-pleated sheets.
Normal PrP have alpha-helices; infectious PrP have beta-pleated sheets.
Which of the following statements concerning prion diseases is true? Prion diseases affect humans but not other animals. Prion diseases are always inherited. Normal host cellular prion proteins (PrPC) are converted into scrapie proteins (PrPSc). Prion diseases affect brain function but do not affect the morphology (overall appearance) of brain tissues.
Normal host cellular prion proteins (PrPC) are converted into scrapie proteins (PrPSc).
Which of the following is the best evidence for a three-domain system? Some bacteria live in extreme environments. There are three distinctly different types of nuclei. There are three distinctly different sets of metabolic reactions. There are three distinctly different Gram reactions. Nucleotide sequences in ribosomal RNA vary between all three domains.
Nucleotide sequences in ribosomal RNA vary between all three domains.
Where are MHC molecules located on a cell? Inside the cell cytoplasm They are not associated with any one location on the cell On the surface of the cell In the nucleus
On the surface of the cell
Which statement regarding endotoxins is true? Endotoxins are part of the outer portion of the cell wall of gram-positive bacteria. Endotoxins induce host cells to produce effective antitoxins that help to protect them against the toxin's effects. The effects of endotoxins vary greatly, depending on the specific bacterium the produces them. One consequence of endotoxins is the activation of blood-clotting proteins.
One consequence of endotoxins is the activation of blood-clotting proteins.
What is considered to be the average natural mutation rate that occurs during DNA replication? One in every billion nucleotides replicated. One in every ten thousand nucleotides replicated. One in every million nucleotides replicated. One in every trillion nucleotides replicated.
One in every billion nucleotides replicated.
How frequently do silent mutations occur? One out of every billion mutations One out of every three mutations Half of all mutations One out of every million mutations
One out of every three mutations
If a person lacked the ability to form C5, what direct result of complement could still occur? Opsonization Chemotaxis Cytolysis
Opsonization
Bacteria that are resistant to sulfonamide have enzymes that have a greater affinity for what? PABA Sulfonamide Tetrahyrdrofolic acid Tetracycline
PABA
Which of the following statements concerning pathology, infection, and disease is true? The majority of microorganisms are pathogenic. The term infection is synonymous with the term disease. Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease. Microorganisms that make up the normal microbiota of an individual never cause disease.
Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease.
In which stage is the viral DNA introduced into the cell? Attachment Release Assembly Biosynthesis Penetration
Penetration
Which antibiotic is overcome by beta-lactamases? Tetracycline Sulfonamide Penicillin Tetracycline, Penicillin, and Sulfonamide are all affected by beta-lactamase.
Penicillin
Why would an efflux pump for penicillin located on a bacterial cell membrane not be effective at providing resistance to the drug? The efflux pumps would not stop penicillin from blocking metabolic pathways. There are fewer efflux pumps on the cell membrane. The cell membrane is the target of penicillin. Penicillin disrupts the cell wall, which is located outside of the cell membrane.
Penicillin disrupts the cell wall, which is located outside of the cell membrane.
According to the animation, antibodies interact with which innate defenses? Inflammation First-line defenses Phagocytosis The complement system Phagocytosis, inflammation, and the complement system Phagocytosis and the complement system
Phagocytosis and the complement system
Which structure do antigen presenting cells utilize to directly help them present bacterial antigens? Nucleus Mitochondria Phagolysosome Golgi apparatus
Phagolysosome
You are given an unknown, pure sample of a eukaryotic organism. Which of the following tests would allow you to determine if the sample contains algae? Inject the organism into a lab animal. If it does not cause disease, it is an alga. Perform a biochemical test for the presence of chitin. Determine if the organism is unicellular by microscopy. If it is unicellular, it is an alga. Place the sample in a clear container filled with media containing no sugars, and leave it in a sunny window. After a few weeks, look for growth of the organism.
Place the sample in a clear container filled with media containing no sugars, and leave it in a sunny window. After a few weeks, look for growth of the organism.
What is the role of plasma cells in humoral immunity? Plasma cells produce antibodies. Plasma cells neutralize toxins. Plasma cells activate the complement system. Plasma cells engulf viruses. Plasma cells are phagocytes.
Plasma cells produce antibodies.
Which of the following is necessary for replication of a prion? DNA DNA polymerase RNA PrPSc lysozyme
PrPSc
How can health care workers reduce the occurrence of nosocomial infections? Practice more stringent aseptic techniques Administer all medications orally instead of through injections Limit the number of visitors who can see the patient Reduce the number of times they visit a patient
Practice more stringent aseptic techniques
From which phrase is the term "prions" derived? Proteinaceous infectious particles Protein infections Particles of infection Protein infection of the nervous system
Proteinaceous infectious particles
How does the number of infectious prions increase? Prions reproduce by mitosis. Prions transform normal proteins into the misfolded beta-pleated sheet configuration; therefore, prions multiply by conversion. Prions form multimers which can then form more single copies of the prion protein. Prions reproduce by binary fission.
Prions transform normal proteins into the misfolded beta-pleated sheet configuration; therefore, prions multiply by conversion.
The earliest vaccinations were against smallpox. Which of the following statements about the history of smallpox vaccinations is FALSE? The earliest vaccinations were called variolations and protected people from smallpox by inoculating them with smallpox matter. Edward Jenner inoculated people with cowpox in an attempt to protect them from smallpox. Proteins from dairy cows were injected into people to protect them from smallpox. Chinese physicians prevented smallpox disease by having children inhale dried smallpox scabs.
Proteins from dairy cows were injected into people to protect them from smallpox.
How is phagocytosis in the immune system different from protozoan phagocytosis? There is no difference between the two. Protozoan phagocytosis is used to fight infection; phagocytosis by immune cells is used to feed the cells. Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection.
Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection.
According to the animation, which of the following makes mRNA from the information stored in a DNA template? DNA polymerase RNA polymerase tRNA Ribosomes
RNA polymerase
Which of the following is NOT a step used by cytotoxic T cells to kill infected host cells? Recognition of infected host cell using its TCR Recognition of infected host cell using its CD4 glycoprotein Secretion of perforin Secretion of granzyme
Recognition of infected host cell using its CD4 glycoprotein
Which of the following statements accurately describes the culture media necessary for growing Clostridium tetani? Nutrient agar contains ingredients that combine with oxygen and remove it, creating an anaerobic environment. Reducing media are complex media containing chemicals, such as thioglycolate, that combine with oxygen, creating an anaerobic environment. A complex medium is one whose exact chemical composition is known. A chemically defined medium is one made up of extracts such as those from yeasts, meat, or plants whose exact chemical composition may vary slightly.
Reducing media are complex media containing chemicals, such as thioglycolate, that combine with oxygen, creating an anaerobic environment.
Sally decides to go through the desensitization program recommended by her doctor. What is the overall purpose/goal of this process? Repeated exposure to wasp venom antigen will increase the amount of IgG produced by Sally's immune system. The process will eliminate all of the wasp venom-specific IgE from Sally's body. During the desensitization process, the number of wasp venom-reactive mast cells will decrease. Desensitization will decrease the overall sensitivity of Sally's immune responses, eliminating its hyperactivity.
Repeated exposure to wasp venom antigen will increase the amount of IgG produced by Sally's immune system.
Which step of binary fission is the reason for genetically identical daughter cells? There are four new daughter cells that result from one parental cell Replication of the bacterial chromosome Elongation of the cell Splitting of the two daughter cells
Replication of the bacterial chromosome
Which operons are always transcribed unless deactivated? Inducible operons Repressible operons Inducible and repressible operons
Repressible operons
How might efflux pumps increase antibiotic resistance in bacteria? Resistant bacteria may have a greater number of efflux pumps on their cell surfaces. Some bacteria can decrease the specificity of their efflux pumps, increasing the number of different antibiotics the pumps can eliminate. Some bacteria can change the chemical structure of the antibiotic. Efflux pumps can never be modified to increase antibiotic resistance. Resistant bacteria can have more efflux pumps, and can have less specific efflux pumps.
Resistant bacteria can have more efflux pumps, and can have less specific efflux pumps.
Which of the following viruses is transcribed from RNA to DNA to RNA during the replication cycle? Retroviruses +RNA viruses dsDNA viruses -RNA viruses
Retroviruses
Which finding is most surprising from Griffith's experiments? S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains. R strain cells fail to produce a capsule. S strains are able to escape phagocytosis. S strain cells kill the mice.
S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains.
What is the etiologic agent of typhoid? E. coli Salmonella Shigella
Salmonella
If a typhoid fever outbreak has occurred, which of the following statements is true? Shigella species are present and may have been transmitted by cattle. Escherichia coli bacteria are present, probably passed on by infected human waste in the water supply. Proteus colonies of Enterobacteriales are probably present. Salmonella is present, and the serovars may be differentiated by antigenic analysis.
Salmonella is present, and the serovars may be differentiated by antigenic analysis.
All of the following organisms produce exotoxins EXCEPT Clostridium tetani. Salmonella typhi. Corynebacterium diphtheriae. Staphylococcus aureus. Clostridium botulinum.
Salmonella typhi.
Which disease did Stanley Prusiner first identify as being caused by prions? Scrapie Kuru Mad cow disease Fatal familial insomnia
Scrapie
Which of the following is an application that uses PCR? Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism Diagnosing a disease Sequencing a gene Providing enough DNA for cloning into another organism
Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism
In mice, the LD50 for staphylococcal enterotoxin is 1350 ng/kg, and the LD50 for Shiga toxin is 250 ng/kg. Which of the following statements is true? The parenteral route is the preferred portal entry for Shigella bacteria. Staphylococcal enterotoxin is the more lethal of the two toxins. Shiga toxin is more lethal than staphylococcal enterotoxin. More organisms of Staphylococcal bacteria must be ingested to cause infection, as compared Shigella bacteria.
Shiga toxin is more lethal than staphylococcal enterotoxin.
Which of the following mutations would not result in antibiotic resistance? Missense mutation Nonsense mutation Silent mutation Frameshift insertion Frameshift deletion
Silent mutation
Which of the following characteristics of a catheter should be considered, to help minimize the spread of nosocomial infections? Washable Single-use Long Reusable Inexpensive
Single-use
Which of the following regarding antimicrobial control agents is false? Some agents affect microbial cell membranes by dissolving lipids. Some agents inactivate viruses by attacking cell membrane lipids. Some agents kill by denaturing microbial cell proteins. Contaminating organic debris such as blood or sputum decrease effectiveness. Silver is used for treating antibiotic-resistant bacteria.
Some agents inactivate viruses by attacking cell membrane lipids.
Which of the following is NOT a verified exception in the use of Kochs postulates? Some human diseases have no other known animal host. Some diseases are noncommunicable. Some diseases are not caused by microbes. Some pathogens can cause several disease conditions. Some diseases have poorly defined etiologies.
Some diseases are noncommunicable.
Which statement concerning viral structure is true? The proteins in the envelope are capsomeres. All viruses contain an envelope, which is made of lipid, carbohydrate, and protein. Spikes are found on some viruses. They are very consistent in structure and can be used for identification. Animal viruses usually contain a tail sheath and spikes.
Spikes are found on some viruses. They are very consistent in structure and can be used for identification.
A child presents with large red patches of skin. The top layers are peeling off. Because the parents report that the child hasn't been burned, you suspect that the lesions are due to infection with __________. Pseudomonas aeruginosa Staphylococcus epidermidis Streptococcus pyogenes Staphylococcus aureus
Staphylococcus aureus
Which of the following virulence factors would be found in Staphylococcus aureus? Collagenase Streptokinase Hyaluronidase Staphylokinase
Staphylokinase
In which phase is the rate of cell death equal to the rate of cell growth? Log phase Death phase Stationary phase Lag phase Log and stationary phase
Stationary phase
Which of the following bacteria are responsible for more infections and more different kinds of infections? Staphylococcus Pseudomonas Salmonella Neisseria Streptococcus
Streptococcus
Which of the following bacteria is gram-positive? Rickettsia Salmonella Streptococcus Bacteroides Pseudomonas
Streptococcus
Which of the following microorganisms use M protein to avoid destruction of a phagocyte? Streptococcus pyogenes Streptococcus pneumoniae Coxiella burnetii Haemophilus influenzae
Streptococcus pyogenes
Which of the following organisms would MOST likely be sensitive to natural penicillin? helminths Penicillium Mycoplasma Streptococcus pyogenes penicillinase-producing Neisseria gonorrhoeae
Streptococcus pyogenes
All of the following are normal microbiota of the skin EXCEPT Staphylococcus. Micrococcus. Corynebacterium. Streptococcus. Propionibacterium.
Streptococcus.
To date, most of our natural antibiotics have been found to be produced by members of what genus? Penicillium Paenibacillus Bacillus Cephalosporium Streptomyces
Streptomyces
More than half of the antibiotics used today are produced by __________. Streptomyces species fungi plants Streptococcus species
Streptomyces species
The Hepatitis B vaccine is which type of vaccine? DNA vaccine Toxoid vaccine Inactivated killed vaccine Subunit vaccine
Subunit vaccine
How are superantigens different from other types of exotoxins? Superantigens cause an overstimulation of the host immune system. Superantigens are comprised of two functional domains. Superantigens must be endocytosed into a target cell before becoming active. Superantigens only act against host neurons.
Superantigens cause an overstimulation of the host immune system.
Which statement regarding the skin is FALSE? The outer layer is composed of dead cells. It is waterproof. Sweat contains an enzyme called lysozyme, which breaks down the cell walls of some bacteria. Sweat glands produce sebum, in addition to sweat.
Sweat glands produce sebum, in addition to sweat.
Which of the following is true regarding systemic anaphylactic reactions? Select all that apply. Systemic reactions can be treated only with an injection of epinephrine. Systemic reactions always involve the respiratory system. Systemic reactions are commonly associated with injected antigens. A systemic reaction can be fatal in only a few minutes. Systemic reactions can result in a dramatic decrease in blood pressure. Systemic reactions are commonly associated with antigens that are ingested or inhaled.
Systemic reactions are commonly associated with injected antigens. A systemic reaction can be fatal in only a few minutes. Systemic reactions can result in a dramatic decrease in blood pressure.
HIV spikes attach to CD4+ receptors found on T helper cells. macrophages. dendritic cells. T helper cells and macrophages. T helper cells, macrophages, and dendritic cells.
T helper cells, macrophages, and dendritic cells.
Which of the following defense systems would be involved in eliminating virally-infected cells? Phagocytosis Humoral immunity T lymphocytes Complement system
T lymphocytes
Which receptor on the helper T-cell recognizes the specific antigen from an antigen-presenting cell? TCR IL-2 Receptors IL-1 Receptors CD4
TCR
Which of the following recognizes antigens displayed on host cells with MHC II? natural killer cell basophil B cell TH cell TC cell
TH cell
The following events elicit an antibody response. What is the third step? TH cell produces cytokines. APC phagocytizes antigen. Antigen-digest goes to surface of APC. TH cell recognizes antigen-digest and MHC II. B cell is activated.
TH cell recognizes antigen-digest and MHC II.
The following events occur in cellular immunity. What is the third step? TH cells proliferate. Antigen enters M cell. TH cell produces cytokines. Antibodies are produced. Dendritic cell takes up antigen.
TH cells proliferate.
Which type of T cell is involved in activating macrophages and stimulating development of cytotoxic T cells? TH1 cells TH2 cells Treg cells CD8+ T cells
TH1 cells
Natural killer cells are activated by bacterial cells. antigen-presenting cells. TH1 cells. TH2 cells.
TH1 cells.
Which of the following statements concerning viruses is true? Viruses contain both DNA and RNA, and they undergo binary fusion. Viruses are usually about the same size as bacteria. Viruses possess enzymes for protein synthesis and ATP generation. The "host range" for a virus is determined by the presence or absence of particular components on the surface of a host cell that are required for the virus to attach.
The "host range" for a virus is determined by the presence or absence of particular components on the surface of a host cell that are required for the virus to attach.
Which of the following does NOT accurately apply to the Ames test? The Ames test is based on the observation that reversions CANNOT occur in mutant bacteria. The test can be used to qualitatively test potential mutagens. The test uses bacteria as mutagen carcinogen indicators. The Ames test measures the reversion of histidine auxotrophs of Salmonella.
The Ames test is based on the observation that reversions CANNOT occur in mutant bacteria.
Which of the following statements is FALSE? S. aureus is differentiated from other mannitol+ cocci by the coagulase test. The M in MRSA stands for mannitol. Antimicrobial therapy for hemodialysis-associated infections increases antibiotic resistance. The USA100 strain accounts for most hospital-acquired MRSA. The USA300 strain accounts for most community-acquired MRSA.
The M in MRSA stands for mannitol.
What most likely explains the recovery of live S strain cells from a mouse injected with heat-killed S strain mixed with live R strain cells? The S strain was revived by the presence of the host's immune system. The R strain cells picked up the capsules from the S strain cells. The R strain picked up the S strain DNA, enabling it to produce a capsule. The S strain fused with the R strain, making it resistant.
The R strain picked up the S strain DNA, enabling it to produce a capsule.
If a person turns their ankle, how would one determine if damage to the tissue in the ankle has occurred? The ankle is very warm to the touch. The ankle is red. The ankle swells. The ankle is red, swollen, and warm to the touch.
The ankle is red, swollen, and warm to the touch.
The following results were obtained from a disk-diffusion test for microbial susceptibility to antibiotics. Staphylococcus aureus was the test organism. Antibiotic Zone of Inhibition A 3 mm B 7 mm C 0 mm D 10 mm In the table, the antibiotic that exhibited bactericidal action was A. B. C. D. The answer cannot be determined based on the information provided.
The answer cannot be determined based on the information provided.
Which of the following best explains why Tori developed a new series of symptoms? The initial antibiotics were not successful in clearing the respiratory infection, so the organism disseminated to the genitourinary tract. Tori's immune system was compromised because of her respiratory infection, and this resulted in a yeast infection. Tori contracted a sexually transmitted infection that was not related to the primary respiratory infection. The antibiotics that treated Tori's primary respiratory infection also removed some of her normal bacterial flora, resulting in an overgrowth of other organisms.
The antibiotics that treated Tori's primary respiratory infection also removed some of her normal bacterial flora, resulting in an overgrowth of other organisms.
How might a pathogenic bacterium be affected by antibodies? The antibodies may block proteins necessary for binding the pathogen to the host, may opsonize the bacterium, or may agglutinate bacteria. The antibodies may block proteins necessary for binding the pathogen to the host. The antibodies may coat the surface of the bacteria (opsonization), allowing for it to be tagged for phagocytosis. The antibodies may stick to multiple bacteria, causing agglutination.
The antibodies may block proteins necessary for binding the pathogen to the host, may opsonize the bacterium, or may agglutinate bacteria.
What is meant when a bacterium is said to become "resistant" to an antibiotic? The antibiotic kills or inhibits the bacterium. The antibiotic is metabolized by the bacterium, providing more energy for growth of the cell. The bacterium is neither killed nor inhibited by the antibiotic. The antibiotic mutates in a way that benefits the bacterium.
The bacterium is neither killed nor inhibited by the antibiotic.
The IgG molecules that are produced during desensitization function as blocking antibodies. These antibodies are extremely effective in providing protection from a hypersensitivity reaction. Why are blocking IgG antibodies so effective at protecting Sally from another anaphylactic response to wasp venom? The IgG antibodies bind to the circulating IgE and block their binding to the mast cells. The blocking IgG antibodies "outnumber" the IgE antibodies and bind to wasp venom before the IgE antibodies can bind. The IgG molecules bind to the mast cells; but when wasp venom binds, IgG blocks degranulation. The IgG molecules bind to mast cells and prevent IgE molecules from binding, thereby preventing degranulation.
The blocking IgG antibodies "outnumber" the IgE antibodies and bind to wasp venom before the IgE antibodies can bind.
Where are the complement proteins found in the body? The liver The thymus The blood serum The spleen In every cell
The blood serum
What occurs during viral uncoating? The viral proteins are synthesized. The viral envelope is released. The nucleic acid breaks apart, allowing for translation. The capsid breaks apart, releasing the viral genome.
The capsid breaks apart, releasing the viral genome.
How does a capsule help certain bacteria evade detection by the immune system? The capsule makes the bacterium too sticky to be phagocytosed by the immune cells. Capsules allow the bacteria to stick together, creating a larger mass that is too big for immune cells to engulf. Capsules have the ability to destroy antibodies secreted by the immune system. The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign.
The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign.
Contaminated hospital equipment represents a difficult environment to control harmful microbial growth. Regarding influences that affect disinfection of hospital equipment, which of the following is an accurate statement? The cell wall of gram-negative bacteria is especially resistant to many chemicals that are used destroy microbes. Antimicrobial agents work best under reduced temperatures. The presence of organic matter, such as dried blood or protein, will not affect the action of antimicrobial agents. Biofilms, often found contaminating hospital equipment, are relatively simple targets for biocides to reach effectively.
The cell wall of gram-negative bacteria is especially resistant to many chemicals that are used destroy microbes.
What characteristic of the S strain allows it to evade the immune system of the mice? The cells have a capsule. They are naturally competent. They are genetically engineered to be resistant to killing. They are resistant to heat.
The cells have a capsule.
Which of the following best describes the pattern of microbial death? Not all of the cells in a culture are killed. The pattern varies depending on the antimicrobial agent. All the cells in a culture die at once. The pattern varies depending on the species. The cells in a population die at a constant rate.
The cells in a population die at a constant rate.
What must occur for bacterial conjugation to take place? The cells must come into contact with each other. The cells must transfer RNA. Each cell must contain a plasmid. One of the cells must be E. coli.
The cells must come into contact with each other.
What enables the copied chromosomes to separate during binary fission? The mitotic spindle drives the separation. The chromosomes are attached to different parts of cell membrane, which elongates and thus separates the chromosomes. The septum splits the replicated chromosomes. The nuclear membrane dissolves.
The chromosomes are attached to different parts of cell membrane, which elongates and thus separates the chromosomes.
Which of the complement pathways was discovered first? The alternative pathway The lectin pathway The classical pathway
The classical pathway
Which of the following statements is FALSE? The Fc region attaches to a host cell. The variable region of a heavy chain binds with antigen. The constant region of a heavy chain is the same for all antibodies. The variable region of a light chain binds with antigen. All of the answers are correct.
The constant region of a heavy chain is the same for all antibodies.
Which of the following statments about measles is FALSE? It is preventable by vaccination. It is a serious disease. The disease has been eradicated in the United States. Complications include pneumonia, encephalitis, and death. Annually, it kills thousands of children worldwide.
The disease has been eradicated in the United States.
In the sixth segment of the animation, why is the disease epidemic in North America? The disease occurs at a higher rate than what would normally be expected in this region. Only a few cases are occurring in this region. The disease has spread to North America from Europe. The disease occurs at a lower rate than what would normally be expected in this region.
The disease occurs at a higher rate than what would normally be expected in this region.
How is fermentation of lactose detected? The medium become turbid when exposed to air. The acetoin produced turns the medium pink. The cells form a black precipitant. The drop in pH turns the indicator dye yellow.
The drop in pH turns the indicator dye yellow.
Which of the following does NOT contribute to the emergence of infectious diseases? Antibiotic resistance Climatic changes New strains of previously known agents Ease of travel The emergence of infectious diseases can be attributed to all of these
The emergence of infectious diseases can be attributed to all of these
Which organelle assists directly with the presentation of MHC-I antigens? The endoplasmic reticulum The nucleus The phagosome The Golgi apparatus The mitochondria
The endoplasmic reticulum
How do the strands separate during PCR? The primers separate the strands during the annealing step. The high heat of the denaturation step breaks the hydrogen bonds between the two strands. The cycling of the temperatures breaks the hydrogen bonds between the two strands. The DNA polymerase breaks the hydrogen bonds between the two strands.
The high heat of the denaturation step breaks the hydrogen bonds between the two strands.
What happens to the packaged DNA of a specialized transduced phage when it infects a new recipient cell? The DNA is chewed up by enzymes found in the recipient cell. The host DNA integrates, with the prophage, into the new recipient chromosome. The DNA begins to replicate without integrating into the host chromosome.
The host DNA integrates, with the prophage, into the new recipient chromosome.
How is the lytic cycle different from the lysogenic cycle with respect to the infected host cell? The host cell dies during the lytic stage. The viral DNA may integrate into the host genome during the lytic stage. The host cell is allowed to live during the lytic stage. The host cell can only divide during the lytic stage.
The host cell dies during the lytic stage.
Why is light required for photolyases? The light provides the energy to break the bonds between the thymine dimers. Light excises the section of DNA to be repaired. Light is used to activate the DNA polymerase to repair the gap. The light helps identify the damaged strands.
The light provides the energy to break the bonds between the thymine dimers.
What is a thermocycler? The process of cycling through the different temperatures of a PCR reaction 30 times The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR The special DNA polymerase, used in a PCR reaction, that can tolerate the high temperatures The name for the DNA primers used in a PCR reaction
The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR
What test result indicates that the unknown can utilize citrate as its sole carbon source? It turns the medium black. The medium turns blue. The culture becomes turbid. The medium turns pink.
The medium turns blue.
Which of the following statements concerning immunological memory is true? The memory response involves only B cells. The memory response is due to production of long-lived cells that can respond very rapidly upon second exposure. The memory response is usually faster but not as strong. Antibodies produced in response to a secondary infection are mostly IgM.
The memory response is due to production of long-lived cells that can respond very rapidly upon second exposure.
How is DNA methylation used in DNA repair? The mismatch-repair enzymes can use a lack of methylation to identify and remove newly synthesized DNA. Methyl groups are required to cut DNA. Methyl groups activate photolyases in light-repair. Methyl groups identify thymine dimers in the DNA.
The mismatch-repair enzymes can use a lack of methylation to identify and remove newly synthesized DNA.
Why are the beta-pleated multimers of PrP potentially pathogenic? They are not detected by other organisms. They repress the immune system. They are found on the surface of immune cells, resulting in damage to the immune system. The multimers are more stable and resistant to protease.
The multimers are more stable and resistant to protease.
According to the animation, where on the DNA strand does a repressor bind? The inducer The promoter The operator The structural genes
The operator
What would happen if the septum did not form during binary fission? Nothing; the septum is not required for binary fission. The chromosome could not replicate. The parent cell would now have two copies of the chromosome. The daughter cells would not be genetically identical.
The parent cell would now have two copies of the chromosome.
Which of the following statements is FALSE? A prophage may result in new properties of the host cell. Prophage genes are repressed by a repressor protein coded for by the prophage. The prophage makes the host cell immune to infection by other phages. A prophage can "pop" out of the chromosome. A prophage is phage DNA inserted into a bacterial chromosome.
The prophage makes the host cell immune to infection by other phages.
Koch's postulates established criteria for proving that a specific organism causes a specific disease. Which of the following is NOT one of the criteria given by Koch's postulates? The pathogen must be isolated from the diseased host and grown in pure culture. The same pathogen must be present in every case of the disease. The pathogen must be isolated from inoculated animals and must be different from the original organism. The pathogen isolated from a pure culture must cause the disease in a healthy lab animal.
The pathogen must be isolated from inoculated animals and must be different from the original organism.
Which of statements best describe Koch's postulates? Select all that apply. The pathogen must be isolated from the inoculated animal and must be shown to be the original organism. The pathogen must be isolated from the diseased host and grown in pure culture. The same pathogen must be present in every case of the disease. The microscopic properties of pathogens isolated from the original (diseased) and inoculated (also, diseased) animals should differ significantly. The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible laboratory animal.
The pathogen must be isolated from the inoculated animal and must be shown to be the original organism. The pathogen must be isolated from the diseased host and grown in pure culture. The same pathogen must be present in every case of the disease. The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible laboratory animal.
Which of the following statements about nosocomial infections is FALSE? They occur in compromised patients. They may be caused by drug-resistant bacteria. The patient was infected before hospitalization. They may be caused by normal microbiota. They may be caused by opportunists.
The patient was infected before hospitalization.
A patient shows the presence of antibodies against diphtheria toxin. Which of the following statements is FALSE? A recent transfusion may have passively introduced the antibodies. The patient may have been vaccinated. The patient may have had the disease and has recovered. The patient was near someone who had the disease. The patient may have the disease.
The patient was near someone who had the disease.
Which of the following statements about the development of infectious diseases is correct? The prodromal period is characterized by very severe symptoms. During the incubation period, the infected individual exhibits obvious signs of sickness. The period of decline is the time when the infected individual's health rapidly deteriorates. The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state).
The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state).
Which is an example of vehicle disease transmission? Touching a telephone with cold viruses on its surface The bite of a mosquito containing malaria The transmission of MRSA from skin to skin contact The presence of Listeria on undercooked chicken served for dinner
The presence of Listeria on undercooked chicken served for dinner
Where does the name "scrapie" come from? The prion disorder causes infected sheep to scrape against objects until their skin is raw. The disease results in the animal wasting away, sending them to the "scrap heap." The prions cause amyloid plaques to scrape against each other.
The prion disorder causes infected sheep to scrape against objects until their skin is raw.
What is apoptosis? The receptor on a cytotoxic T-cell that recognizes MHC molecules. The proliferation of cytotoxic T-cells. A protein molecule that forms a pore in the membranes of infected cells. The process of programmed cell death.
The process of programmed cell death.
How does specialized transduction differ from regular lysogeny? The resulting bacteriophage from specialized transduction does not contain any viral DNA. The resulting bacteriophage from specialized transduction cannot infect a new host cell. The prophage is not excised during specialized transduction. The prophage in specialized transduction carries with it pieces of the host chromosomal DNA.
The prophage in specialized transduction carries with it pieces of the host chromosomal DNA.
Which of the following bacteria is gram-negative? Mycobacterium Treponema Bacillus Staphylococcus Corynebacterium
Treponema
How can specialized transduction contribute to the transfer of antibiotic resistance genes in a bacterial population? The phage causes the destruction of any antibiotic present during the specialized transduction process. The prophage takes an antibiotic resistance gene with it and is packaged with the newly synthesized viral DNA. The phage lyses the bacterium and releases resistance genes into the local environment, which can then be taken up by recipient cells.
The prophage takes an antibiotic resistance gene with it and is packaged with the newly synthesized viral DNA.
How is the secondary response different from the primary response in terms of antibody concentration in the blood? The secondary response is slower, but produces more antibodies than the primary response. The secondary response is faster and produces more antibodies than the primary response. The secondary response is faster, but does not produce more antibodies than the primary response. There is no difference with regard to antibody concentration in the blood.
The secondary response is faster and produces more antibodies than the primary response.
Which statement correctly describes the normal microbiota of the skin? Vigorous washing will eliminate all skin bacteria. Most microorganisms that grow on the skin are sensitive to drying. The skin's normal microbiota are capable of growth at elevated salt concentrations. On superficial skin surfaces, certain anaerobic bacteria produce fatty acids from oil gland secretions.
The skin's normal microbiota are capable of growth at elevated salt concentrations.
Which of the following genetic elements is transcribed into a single mRNA? The repressor The inducer The structural genes The promoter The operator
The structural genes
What is a phagolysosome? A protein that covers the surface of an invading microbe, making it easier for the phagocyte to ingest. The structure that results from the fusion of a phagosome and a lysosome. A vesicle containing only digestive enzymes and other antimicrobial compounds. A vesicle containing only an engulfed invading microorganism.
The structure that results from the fusion of a phagosome and a lysosome.
If mosquitoes are the mode of transmission for West Nile virus, why did the students in Bill's virology class focus on finding the virus in the dead birds rather than collecting mosquitoes to examine? The students tried to isolate and identify West Nile virus from birds because they are large animals. It would be difficult to isolate West Nile virus from mosquitoes because they are small. The students tried to isolate and identify West Nile virus from birds because they had access to dead birds that were known to be infected with West Nile virus. The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals. The students tried to isolate and identify West Nile virus from birds because it is faster to isolate the virus from a bird than to isolate it from a mosquito.
The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals.
Adjuvants such as aluminum salts are used as additives in vaccines to enhance immune responses. True False
True
Which of the following statements concerning necrotizing fasciitis is FALSE? Some cases require limb amputation. The tissue damage is mainly due to the production of endotoxin, which stimulates a severe immune response. It is often associated with streptococcal toxic shock syndrome. It may be caused by several different organisms, but Streptococcus pyogenes is the most common.
The tissue damage is mainly due to the production of endotoxin, which stimulates a severe immune response.
A lytic virus has infected a patient. Which of the following would best describe what is happening inside the patient? The virus is slowly killing the patients cells. The virus is causing the death of the infected cells in the patient. The virus is incorporating its nucleic acid with that of the patients cells. The virus is not killing any cells in the host. The virus is infecting cells and then releasing only small amounts of virus.
The virus is causing the death of the infected cells in the patient.
What would be the fate of a lytic bacteriophage if the host cell died prior to the assembly stage? The cell could still be revived by the virus. The virus would infect new hosts. The virus would not be able to infect new hosts.
The virus would not be able to infect new hosts.
Consider a helminthic infection in which an individual is colonized by a parasitic worm. The worm is too big to be engulfed by a phagocytic cell. How does the immune system respond? Numerous phagocytes work cooperatively to ingest the worm. The worm gets coated with antibodies, which activate other cells in the immune system to secrete chemicals that kill it. Antibodies bind to the worm and disrupt its plasma membrane. Blood flow is reduced to the area, which starves the worm of nutrients.
The worm gets coated with antibodies, which activate other cells in the immune system to secrete chemicals that kill it.
How is Streptococcus pneumoniae able to avoid destruction by a phagocyte? They cause the lysosomes to empty their contents into the phagocyte, killing it. They prevent the fusion of the lysosome and phagosome. Their capsules make them "slippery" to phagocytes.
Their capsules make them "slippery" to phagocytes.
How do naked viruses differ from enveloped viruses in their attachment/penetration phase? Their protein coat fuses to the cell membrane. Their nucleic acids are injected into the cell. They uncoat after they enter the cell. Their DNA attaches to receptors on the cell surface.
Their nucleic acids are injected into the cell.
Which of the following statements is TRUE? All of the complement proteins are constantly active in serum. Complement increases after immunization. There are at least thirty complement proteins. Complement activity is antigen-specific. Factors B, D, and P cause cytolysis.
There are at least thirty complement proteins.
Why is vaccination for rubella recommended? Death from secondary infections is common. There is a high incidence of congenital infections and birth defects. It is no longer recommended; rubella has been eradicated. Health care workers have a high incidence of infection. It has a high mortality rate in school-age children.
There is a high incidence of congenital infections and birth defects.
Which of the following statements regarding infections involving biofilms is FALSE? There is no way to prevent biofilms from developing on surfaces. It is estimated that nearly 70% of all infections are caused by biofilms. Microbes in biofilms are 1000x more resistant to antimicrobials than are independent organisms. The majority of hospital acquired infections (nosocomial infections) are related to biofilms.
There is no way to prevent biofilms from developing on surfaces.
There are a large number of antibiotics that inhibit protein synthesis at 70s ribosomes found in bacterial cells but do not interfere with protein synthesis at the 80s ribosomes found in eukaryotic cells. Some of these antibiotics bind to the smaller ribosomal subunit and interfere with the reading of the mRNA code, whereas others bind to the larger ribosomal subunit and inhibit the formation of peptide bonds. Unfortunately, some of the antibiotics that inhibit protein synthesis in bacteria exhibit some toxicity to the eukaryotic host cells as well. What is the most likely reason for this toxicity to the host cell? Select the correct answer. These antibiotics plug up the membrane transport mechanisms in eukaryotic cells. These antibiotics interfere with protein synthesis within eukaryotic mitochondria. These antibiotics bind to eukaryotic cytoplasmic ribosomes. These antibiotics interfere with DNA replication in eukaryotic cell nuclei. These antibiotics bond to eukaryotic tRNA.
These antibiotics interfere with protein synthesis within eukaryotic mitochondria.
Why are invasive procedures likely to increase the risk of nosocomial infections? Invasive procedures must use antibiotics. These procedures allow microbes from the skin to enter the bloodstream of the patient. These procedures are carried out by health care workers, who carry resistant microbes. Invasive procedures require long term hospital stays, thereby increasing the number of visitors seen by the patient.
These procedures allow microbes from the skin to enter the bloodstream of the patient.
What is the hallmark of a conjugated vaccine? They contain only the non-pathogenic elements of a pathogen, not the entire cell. They contain the DNA from a pathogenic virus. These vaccines contain weakly antigenic elements plus a more potent antigenic protein.
These vaccines contain weakly antigenic elements plus a more potent antigenic protein.
Which of the following are functions of lectins? They can activate C2 and C4. They produce antibodies. They act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4. They act as opsonins for phagocytosis. They attach to carbohydrates on some bacterial and viral surfaces. They produce factor P (properdin).
They act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4.
What direct effect do histamines and leukotrienes have on capillaries? They prevent phagocytes from sticking to the walls of capillaries. They decrease the diameter of capillaries. They allow capillary walls to open and become leaky.
They allow capillary walls to open and become leaky.
Why are flowcharts useful for dichotomous keys? They allow the researcher to get the answer without having to do many tests. They provide a map to the answer. They allow the researcher to visualize relationships between different bacteria.
They allow the researcher to visualize relationships between different bacteria.
Which of the following is NOT a property of useful vectors? They must be able to self-replicate. They always contain only one gene. They must have properties that allow their survival in the host cell. They must be small enough to allow them to be manipulated prior to injection.
They always contain only one gene.
How are immune cells able to detect foreign pathogens? They detect foreign, unfamiliar chemical substances released by the invading cells. They can compare the DNA sequences from the foreign cells to host DNA. They are able to detect structures on the surfaces of foreign cells that are not found in the host.
They are able to detect structures on the surfaces of foreign cells that are not found in the host.
Which of the following is NOT a reason why monoclonal antibodies (Mabs) are useful? They can be produced in large quantities. They are uniform. They are highly specific. They are always highly sensitive.
They are always highly sensitive.
What do hyaluronidase and kinase have in common? They are both critical components of microbial capsules. They both break down components of the extracellular matrix. They both directly prevent phagocytosis. They are both enzymes involved in evading host defense. All of the above are correct.
They are both enzymes involved in evading host defense.
Which of the following treatments is the most effective for controlling microbial growth? 63°C for 30 minutes 72°C for 15 seconds 140°C for 4 seconds They are equivalent treatments. None of the answers is correct.
They are equivalent treatments.
Which of the following statements about viral spikes is FALSE? They are composed of carbohydrate-protein complexes. They bind to receptors on the host cell surface. They are found only on nonenveloped viruses. They may cause hemagglutination. They are used for attachment.
They are found only on nonenveloped viruses.
Which statement best describes restriction enzymes? They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences. They are necessary for the polymerase chain reaction (PCR) to occur. They can cut only circular plasmid DNA. They randomly cut DNA molecules to generate numerous fragments.
They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences.
Which of the following statements concerning antigen-presenting cells is true? They are involved in activating T cells. They transport antigens to the liver, where they can be degraded. They are found only in lymphoid tissues. They are a type of T cell.
They are involved in activating T cells.
First line defenses have what aspect in common with each other? They recognize specific pathogens. They involve unique cells that attack invading pathogens. They are physical barriers against invading pathogens. They involve the production of antibodies.
They are physical barriers against invading pathogens.
Which of the following statements about exotoxins is generally FALSE? They are composed of proteins. They are more potent than endotoxins. They have specific methods of action. They are resistant to heat. They are produced by gram-positive bacteria.
They are resistant to heat.
What is a feature of the small fragments presented by MHC-I proteins? They are derived from bacteria. They are large proteins from the host. They are small peptides, roughly 8-10 amino acids long. They are small fragments of nucleic acids, 8-10 nucleotides in length.
They are small peptides, roughly 8-10 amino acids long.
Which of the following statements about natural killer cells is FALSE? They destroy cells lacking MHC I. They destroy tumor cells. They are stimulated by an antigen. They destroy virus-infected cells. None of the answers are correct; all of these statements are true.
They are stimulated by an antigen.
Which of the following is NOT an advantage of using live attenuated vaccines? They are usually safer than other types of vaccines. They often produce a more complete type of immunity that includes both humoral and cell-mediated components. They are usually highly effective. They often do not require boosters.
They are usually safer than other types of vaccines.
How do fibrinolysins enhance a pathogen's virulence? They break down fibrin proteins that are involved in clot formation, allowing the cells to penetrate deep into damaged skin. They destroy the molecules that hold cells together. They destroy the fibers that are found at the base of superficial tissues, allowing for deeper penetration by the pathogen.
They break down fibrin proteins that are involved in clot formation, allowing the cells to penetrate deep into damaged skin.
In which of the following respects is measles similar to German measles (rubella)? They are caused by the same virus. They have a similar type of rash. Congenital complications may occur. They can be controlled by vaccination. Encephalitis is a possible complication.
They can be controlled by vaccination.
How do Shigella cells move between host cells? They are secreted directly into the epithelial cells from the M cells. They lyse the M cell, releasing thousands of new cells to infect other host cells. They are secreted by phagocytes. They can polymerize actin molecules from the epithelial cells into tail-like structures that propel them from one cell to another.
They can polymerize actin molecules from the epithelial cells into tail-like structures that propel them from one cell to another.
Which of the following statements provides the most significant support for the idea that viruses are nonliving chemicals? They are filterable. They are chemically simple. They are not composed of cells. They cannot reproduce themselves outside a host. They cause diseases similar to those caused by chemicals.
They cannot reproduce themselves outside a host.
Which of the following statements about drugs that competitively inhibit DNA polymerase or RNA polymerase is FALSE? They are used against viral infections. They can affect host cell DNA. They cause mutations. They cause cellular plasmolysis. They interfere with protein synthesis.
They cause cellular plasmolysis.
How do superantigens enable pathogens to hide from the immune system if they actually stimulate the immune system? They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen. They cause the immune system to destroy IgA antibodies. They cause the immune system to turn on itself. They cause fever, which destroys the complement proteins.
They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen.
What is the hallmark of dichotomous keys? They only relate to biochemical processes of the cell. They are open-ended questions. They only relate to the shape of the cell. They consist of a series of paired statements, in which only one statement of each pair applies to a given organism.
They consist of a series of paired statements, in which only one statement of each pair applies to a given organism.
What is the role of opsonins? They attract phagocytes to the location of infection. They are present on the surface of phagocytes. They aid in the formation of the phagolysosome. They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.
They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.
How do restriction enzymes cut DNA sequences? They cut DNA at sequences that have lots of adenine bases. They have the ability to cut DNA randomly. They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.
They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.
Which of the following statements about fixed macrophages is FALSE? They are cells of the mononuclear phagocytic system. They gather at sites of infection. They develop from neutrophils. They are found in certain tissues and organs. They are mature monocytes.
They develop from neutrophils.
Which of the following statements about Archaea is false? They evolved before bacteria. They are prokaryotes. Some produce methane from carbon dioxide and hydrogen. They lack peptidoglycan in their cell walls. Some are thermoacidophiles; others are extreme halophiles.
They evolved before bacteria.
Which of the following statements about human embryonic stem cells is FALSE? They are pluripotent. They are typically obtained from the blastocyst stage of embryonic development. They are undifferentiated. They express few MHC I antigens. They express MHC II antigens.
They express MHC II antigens.
Which of the following best describes the mode of action of aminoglycosides? They disrupt the cell wall. They interfere with protein synthesis by changing the shape of the ribosome. They disrupt the plasma membrane. They interfere with purine biosynthesis.
They interfere with protein synthesis by changing the shape of the ribosome.
Which of the following statements about type I reactions is FALSE? The symptoms are due to histamine. They involve helper T cells. Antibodies bind to mast cells and basophils. They involve IgE antibodies. The symptoms occur soon after exposure to an antigen.
They involve helper T cells.
How are prions different from other infectious agents? They cause neurological disease. They lack protein. They lack nucleic acid. They cannot replicate.
They lack nucleic acid.
Which of the following is NOT an advantage of live attenuated vaccine agents? They require few or no booster immunizations. They stimulate by cell-mediated and humoral immune responses. The immune response generated by the vaccine closely mimics a real infection. They elicit lifelong immunity. They occasionally revert to virulent forms.
They occasionally revert to virulent forms.
How do phagocytes communicate to other cells what they have captured? They engulf virally infected cells. They present antigens from engulfed foreign cells. They spread viruses to other cells.
They present antigens from engulfed foreign cells.
Which statement regarding cyanobacteria is true? They use hydrogen sulfide (H2S) as a primary reactant as they produce carbohydrate and water. They produce oxygen from water as they carry out photosynthesis. They use reduced sulfur compounds to produce granules of sulfur. They produce carbon dioxide (CO2) from water and oxygen.
They produce oxygen from water as they carry out photosynthesis.
What is the fate of activated cytotoxic T-cells? They proliferate into a clone of cells specific to the same antigen; some of these cells then differentiate into long-lived memory T-cells, while others mature to attack infected cells. They are infected by viruses. Each activated cytotoxic T-cell proliferates, forming a clone of cells specific to the same antigen. They can mature and attack infected cells. They can differentiate into long-lived memory T-cells. They are destroyed via apoptosis.
They proliferate into a clone of cells specific to the same antigen; some of these cells then differentiate into long-lived memory T-cells, while others mature to attack infected cells.
What is the function of the primers in PCR? They provide energy for the DNA polymerization reactions. They provide a 3' end for the DNA polymerase. They are the monomer building blocks from which the DNA strand is synthesized. They polymerize free nucleotides to form the new DNA strands.
They provide a 3' end for the DNA polymerase.
Which of the following is NOT a characteristic of B cells? They originate in bone marrow. They are responsible for antibody formation. They recognize antigens associated with MHC I. They are responsible for the memory response. They have antibodies on their surfaces.
They recognize antigens associated with MHC I.
How are viruses different from cells? They do not contain enzymes. They require a host in order to reproduce. They do not contain protein. They do not contain genetic material.
They require a host in order to reproduce.
How can surgeons help to limit nosocomial infections? They should prescribe immunosuppressive drugs to their patients. They should prescribe as many antibiotics as possible. They should perform surgeries and invasive procedures only when absolutely necessary. They should only operate on healthy individuals.
They should perform surgeries and invasive procedures only when absolutely necessary.
How are negative stains different from other types of stains? They stain the background, leaving the cells colorless. They stain more than one type of specimen. They stain the desired structure or specimen black.
They stain the background, leaving the cells colorless.
Which of the following statements about the members of the Kingdom Animalia is false? They are heterotrophs. They are composed of eukaryotic cells. They undergo photosynthesis. They are multicellular. They ingest nutrients through a mouth.
They undergo photosynthesis.
Which of the following statements about members of the Kingdom Plantae is false? They use organic carbon sources. They undergo photosynthesis. They synthesize organic molecules. They are composed of eukaryotic cells. They are multicellular.
They use organic carbon sources.
How many questions are needed in this dichotomous key to determine if the unknown is Bacteroides? Four Three Five Two
Three
Why is it necessary to give the HPV vaccine in multiple doses? The viral DNA used in the vaccine needs a long time to integrate into the host genome and elicit an immune response. Vaccines for viruses must be given in multiple doses because the viral particles are not very immunogenic. Three doses of the HPV vaccine are given to elicit both a humoral and a cell-mediated response. DNA vaccines are not very stable; therefore, multiple doses must be given to ensure an immune response.
Three doses of the HPV vaccine are given to elicit both a humoral and a cell-mediated response.
Some studies have indicated that the ID50 for Vibrio cholerae can be as high as 108 organisms. Which of the following most likely explains the requirement for this relatively high ID50? To establish infection, V. cholerae must survive the host immune response and the acidic environment of the stomach. Because the major virulence factor of V. cholerae is cholera toxin, large numbers of bacteria are required to produce enough toxin to cause disease. V. cholerae does not produce enough virulence factors to overcome the host response and cause disease. Because V. cholerae cells are relatively small compared to host cells, thousands of bacteria must infect each cell to cause disease.
To establish infection, V. cholerae must survive the host immune response and the acidic environment of the stomach.
What is the fundamental purpose of staining in light microscopy? To make the specimen appear larger in the microscope To see the specimen without the aid of a microscope To kill the specimen To increase the contrast and visibility of the specimen
To increase the contrast and visibility of the specimen
In general, how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene? To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene To remove an undesirable gene To insert a desirable gene To replace a defective gene with a working gene
To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene
What is the role of epidemiology? To learn what diseases can be caused by respiratory pathogens. To learn which organisms cause disease. To learn how to treat and prevent various diseases. To learn which medicines are effective at killing pathogens.
To learn how to treat and prevent various diseases.
What is the function of the structural elements of a virus? To provide a source of energy for the virus To package and protect the viral genome To use all of the cell proteins
To package and protect the viral genome
What is the end goal of PCR? To quickly increase the number of copies of a specific DNA sequence To increase the pool of different DNA sequences To allow cells to make DNA faster, thereby growing faster
To quickly increase the number of copies of a specific DNA sequence
What is the function of inflammation in response to a burn from a hot iron? To repair the damaged tissue To destroy the agent causing injury To destroy the agent causing injury, to limit the effects of the agent on the rest of the body, and to repair the damaged tissue To limit the effects of the agent on the rest of the body
To repair the damaged tissue
Tom has a genetic disorder in which he does not synthesize class I MHC proteins or functional NK cells. Which of the following statements would be true for Tom? Tom would be more susceptible to bacterial infections. Tom would not be able to destroy virally-infected cells. Tom would be less susceptible to helminth infections. Tom would not be able to produce antibodies against viruses.
Tom would not be able to destroy virally-infected cells.
What is unique about transduction compared to normal bacteriophage infection? The bacteriophage does not erupt from an infected cell during transduction. The bacteriophage takes fragments of the cell with it during transduction. Transduction transfers DNA from the chromosome of one cell to another.
Transduction transfers DNA from the chromosome of one cell to another.
Which of the following is an example of horizontal gene transfer in bacteria? Transformation Conjugation Transduction Conjugation and transformation Transduction, conjugation, and transformation
Transduction, conjugation, and transformation
What is the hallmark of all horizontal gene transfers? Transfer of DNA from parent to offspring Transfer of DNA using a virus The use of plasmids Transfer of DNA between organisms of the same generation
Transfer of DNA between organisms of the same generation
Following an endospore stain, how does one distinguish endospores from vegetative cells? Vegetative cells are pink, endospores are green. Vegetative cells are purple, endospores are pink. Vegetative cells are pink, endospores are purple. Vegetative cells are green, endospores are pink.
Vegetative cells are pink, endospores are green.
Which of the following are properties of exotoxins? Select all that apply. Exotoxins are extremely heat stable. Very small amounts of exotoxin can be lethal. Exotoxins are protein molecules. Exotoxins are released from the cell during death or replication. Exotoxins target specific cellular structures or molecules. Exotoxins are produced primarily by gram-negative bacteria.
Very small amounts of exotoxin can be lethal. Exotoxins are protein molecules. Exotoxins target specific cellular structures or molecules.
Which of the following toxins does NOT match the description? hemolysins: membrane-disrupting toxins that destroy erythrocytes tetanus toxin: an A-B neurotoxin that causes uncontrollable muscle contractions Vibrio enterotoxin: a superantigen that destroys epithelial cells streptococcal erythrogenic toxin: a superantigen that damages capillaries and results in a characteristic rash
Vibrio enterotoxin: a superantigen that destroys epithelial cells
Which statement regarding viral species is true? Viral species are classified within the Kingdom Plantae in the Domain Eukarya. Viruses are classified as prokaryotes. Viral species are taxonomically differentiated based upon their cell wall. Viral species are not classified as part of any of the three domains.
Viral species are not classified as part of any of the three domains.
Which of the following is true of viroids? Viroids are typically extremely long and contain numerous genes. Viroid is the term for a virus that infects plants. Viroids are short pieces of naked RNA. There are similarities between the base sequences of viroids and exons, resulting in the hypothesis that viroids evolved from exons.
Viroids are short pieces of naked RNA.
How do all viruses differ from bacteria? Viruses do not reproduce. Viruses are obligate intracellular parasites. Viruses are filterable. Viruses are not composed of cells. Viruses do not have any nucleic acid.
Viruses are not composed of cells.
Which of the following statements is a reason for NOT classifying viruses in one of three domains rather than in a fourth domain? Viruses are obligate parasites. Viruses direct anabolic pathways of host cells. Viruses are not composed of cells. Some viruses can incorporate their genome into a host's genome. All of the answers are correct.
Viruses are not composed of cells.
Why is it difficult to find good chemotherapeutic agents against viruses? Viruses are not cells, and therefore not sensitive to such compounds. There is no effective way to deliver the drug to the virus. Viruses depend on the host cell's machinery, so it is hard to find a viral target that would leave the host cell unaffected. Viruses infect both bacteria and human cells.
Viruses depend on the host cell's machinery, so it is hard to find a viral target that would leave the host cell unaffected.
Why is it more difficult to treat viral infections than it is to treat bacterial infections? Viruses have cell walls. Viruses are very similar to human cells. Viruses are smaller than human cells. Viruses use the host cell's processes to carry out their own reproduction.
Viruses use the host cell's processes to carry out their own reproduction.
Which of the following statements about viruses is FALSE? Viruses contain a protein coat. Viruses use their own catabolic enzymes. Viruses have genes. Viruses use the anabolic machinery of the cell. Viruses contain DNA or RNA but never both.
Viruses use their own catabolic enzymes.
As a health care worker, I am keenly aware of how important it is to avoid harming my patients. I worry about inadvertently transmitting an infectious disease to an already compromised individual. According to the CDC, what is the MOST important thing I can do to avoid this? Shave my head. Wear shoe covers. Wash my hands before interacting with any patient. Wear a lab coat.
Wash my hands before interacting with any patient.
What does a vaccine contain? Weakened or killed pathogen or parts of a pathogen T cells against a pathogen Live active pathogens B cells against a pathogen
Weakened or killed pathogen or parts of a pathogen
What features of West Nile virus make it an emerging disease of special concern? Select all that apply. West Nile virus is an arthropod-borne virus transmitted by mosquitoes. West Nile virus has a high mortality rate in immunosuppressed humans and infects many species of birds in southern Europe, the Mediterranean basin, and North America. West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods. West Nile virus has a positive, single-stranded RNA genome that is 11,000 to 12,000 nucleotides long.
West Nile virus is an arthropod-borne virus transmitted by mosquitoes. West Nile virus has a high mortality rate in immunosuppressed humans and infects many species of birds in southern Europe, the Mediterranean basin, and North America. West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods.
Which of the following best describes why West Nile Virus is considered to be an emerging infectious disease? West Nile virus causes an infection and death in birds such as crows and blue jays. West Nile virus causes a latent viral infection that can emerge later in life. West Nile virus was first isolated in Uganda in 1937 and has caused significant outbreaks every year since then. West Nile virus outbreaks have increased in number and affected areas since 1937.
West Nile virus outbreaks have increased in number and affected areas since 1937.
Which of the following techniques could be used to identify antibodies produced by a patient? Western blotting FISH Southern blotting FAME
Western blotting
Which of the following statements about protozoa is true? When conditions become harsh, some protozoa can form a protective capsule, which is called a cyst. All protozoa can undergo sexual reproduction. Most protozoa are photosynthetic. Some protozoa reproduce by schizogony, a process that is virtually identical to the budding process that happens in some yeast.
When conditions become harsh, some protozoa can form a protective capsule, which is called a cyst.
When would endotoxins be released from a bacterial cell? When the cell moves toward a energy source During bacterial conjugation When the cell attaches to a host cell in the human body When the cell dies
When the cell dies
Which statement about bacterial growth is true? Log phase of growth represents the highest total number of living and dead cells. When the log of the number of cells is plotted versus the generation, the graph is linear. All bacteria have a generation time of 20 minutes. There are only three phases of growth: lag, logarithmic, and stationary.
When the log of the number of cells is plotted versus the generation, the graph is linear.
The level of HIV population in the blood is highest: When the patient has clinical AIDS When CD4+ levels are the highest When the patient is asymptomatic
When the patient is asymptomatic
Which of the following is an event that ultimately results in activation of complement C3 by splitting it into C3a and C3b? interaction of mannose-binding lectin with mannose molecules on a bacterium linkage of C2b with C4a binding of C2 to antigen-antibody complexes binding of factors B, D, and P to antibodies on bacteria
Which of the following are best described as short chains of amino acids that are very stable and can have a variety of different antimicrobial activities, such as forming pores in bacterial plasma membranes and inhibiting cell wall synthesis? antimicrobial peptides antiviral proteins siderophores mannose-binding lectin
Why is baker's yeast useful for expressing genetically engineered genes? The yeast cells are best suited for making human products for medical use. Yeast cells are eukaryotic and so would likely be successful in expressing eukaryotic genes. Many inducible promoters from the yeast genome have been cloned, such as the lac operon. The yeast cells do not secrete their protein products.
Yeast cells are eukaryotic and so would likely be successful in expressing eukaryotic genes.
What is the key difference between yeast and mold? Yeast is colonial, while mold is multicellular. Yeast is unicellular, while mold is multicellular. Yeast have cellulose cell walls, while mold has chitin cell walls. Yeast is a fungus, while mold is an alga.
Yeast is unicellular, while mold is multicellular.
How do pseudohyphae in yeasts differ from vegetative hyphae in filamentous fungi? Yeasts use pseudohyphae to invade host tissue, whereas filamentous fungi use their vegetative hyphae for obtaining nutrients. Yeasts use pseudohyphae as a means of sexual reproduction, whereas parasitic fungi use their hyphae to invade host tissue. Yeasts use pseudohyphae as a means of obtaining nutrients, whereas filamentous fungi use vegetative hyphae as a means of reproduction. Yeasts use pseudohyphae for obtaining nutrients, whereas filamentous fungi use their vegetative hyphae to invade host tissues.
Yeasts use pseudohyphae to invade host tissue, whereas filamentous fungi use their vegetative hyphae for obtaining nutrients.
You have a culture of bacteria that you suspect is either Staphylococcus aureus or Streptococcus pyogenes. Is there any morphological difference between the two? Yes. S. aureus is gram-positive, and S. pyogenes is gram-negative. Yes. S. aureus tends to grow in clusters, whereas S. pyogenes tends to grow in chains. Yes. S. aureus is a coccus, whereas S. pyogenes is a bacillus (rod). No. There is absolutely no difference in the appearance of the cells.
Yes. S. aureus tends to grow in clusters, whereas S. pyogenes tends to grow in chains.
Which of the following methods could be used to differentiate between a member of domain Bacteria and a member of domain Archaea? You could look for the presence of mitochondria. You could look for the presence of peptidoglycan. You could see if the organism produces rRNA. You could see if the organism can survive in an extreme environment. All of the above would work. None of the above would work.
You could look for the presence of peptidoglycan.
If you used a broken thermocycler that could not heat above 75°C, which of the following problems could you expect? You would get more amplification than with a "normal" thermocycler. You would get some significant amplification, but less than if you used a "normal" thermocycler. You would not get any amplification of DNA. You would get the same amount of amplification as with a "normal" thermocycler.
You would not get any amplification of DNA.
In the figure, which areas are different for all IgM antibodies? a and b a and c b and c c and d
a and b
In the figure, which areas represent antigen-binding sites? a and b a and c b and c c and d b and d
a and b
What is an adjuvant? a vaccine that contains only nucleic acids a chemical additive that increases the effectiveness of vaccines a molecule physically linked to another molecule to stimulate antibody production a chemical additive that increases the safety of vaccines
a chemical additive that increases the effectiveness of vaccines
Which of the following is the best definition of antigen? a chemical that combines with antibodies a protein that combines with antibodies something foreign in the body a pathogen a chemical that elicits an antibody response and can combine with these antibodies
a chemical that elicits an antibody response and can combine with these antibodies
Which of the following new chemicals would NOT be effective against Giardia? a chemical that inhibits the formation of cell walls a chemical that inhibits formation of the membrane around the nucleus a chemical that inhibits the Krebs cycle a chemical that inhibits cell division
a chemical that inhibits the formation of cell walls
In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes a aram-negative infection. the disease to subside. a fever. an increase in red blood cells. a decrease in blood pressure.
a decrease in blood pressure.
In an immunodiffusion test to diagnose histoplasmosis, a patient's serum is placed in a well in an agar plate. In a positive test, a precipitate forms as the serum diffuses from the well and meets material diffusing from a second well. In this test process, what is in the second well? mycelia a fungal antigen fungal cells antibodies red blood cells
a fungal antigen
Which of the following is a fomite? a hypodermic needle pus droplets from a sneeze water insects
a hypodermic needle
If a new bacterial pathogen entered a human body through an accidental needle stick, the first cell that would try to kill the pathogen would likely be a cytotoxic T cell. a phagocyte. an antibody-producing cell.
a phagocyte.
In an immunodiffusion test to diagnose histoplasmosis, a patient's serum is placed in a well in an agar plate. In a positive test, a line forms as the serum diffuses from the well and meets material diffusing from a second well. What type of test is this? a precipitation reaction an ELISA test an agglutination reaction a direct test a complement-fixation test
a precipitation reaction
Lysogenic viral DNA integrating into the host genome is referred to as lytic. a prophage. induction. lysogeny.
a prophage.
Which of the following best defines a strain? a population of cells with similar characteristics a pure culture that is not totally identical to other cultures of the same species a group of organisms with a limited geographical distribution a group of cells derived from a single parent same as a species
a pure culture that is not totally identical to other cultures of the same species
When the wasps stung Sally, the injection of venom initiated a type I hypersensitivity reaction called anaphylaxis. Which of the following best describes a hypersensitivity reaction? an immune response that results in an overproduction of IgG a hyperactive immune response generated upon initial exposure to antigen an immune response characterized by an overproduction of T cytotoxic cells a reaction that occurs in a sensitized individual resulting in tissue damage rather than immunity
a reaction that occurs in a sensitized individual resulting in tissue damage rather than immunity
What contributes to antigenic shift in influenza viruses? ease of virus transmission attachment spikes a segmented genome different virus subtypes worldwide distribution of the virus
a segmented genome
A gene is best defined as a sequence of nucleotides in RNA that codes for a functional product. a transcribed unit of DNA. three nucleotides that code for an amino acid. a sequence of nucleotides in DNA that codes for a functional product. a segment of DNA.
a sequence of nucleotides in DNA that codes for a functional product.
A genus can best be defined as a taxon belonging to a species. a taxon composed of families. a taxon composed of one or more species and below family. a taxon comprised of classes. the most specific taxon.
a taxon composed of one or more species and below family.
Which of the following could Tori's physician choose as a treatment for her yeast infection? Select all that apply. a topical over-the-counter ointment, such as clotrimazole or miconazole an oral narrow-spectrum antibiotic, such as penicillin G an antiviral medication, such as acyclovir a single oral dose of fluconazole
a topical over-the-counter ointment, such as clotrimazole or miconazole a single oral dose of fluconazole
During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years. the situation is an example of human reservoirs. a focal infection. a nonliving reservoir. a zoonosis. a vector.
a zoonosis.
A definitive host harbors which stage of a parasite? cyst miracidium adult larva All of the answers are correct.
adult
All of the following pertain to fever EXCEPT that it stimulates T lymphocyte activity. is caused by interleukin-1 and TNF-alpha coming into contact with the hypothalamus. accelerates microbial growth by increasing iron absorption from the digestive tract. intensifies the effect of antiviral interferons. can be initiated by specific types of pathogens.
accelerates microbial growth by increasing iron absorption from the digestive tract.
Staphylococcus aureus is responsible for all of the following EXCEPT carbuncles. sties. acne. pimples. boils.
acne.
A nosocomial infection is always caused by pathogenic bacteria. always present, but is inapparent at the time of hospitalization. always caused by medical personnel. only a result of surgery. acquired during the course of hospitalization.
acquired during the course of hospitalization.
Cytokines released by TH1 cells convert TH1 cells to TH2 cells. kill parasites. activate CD8+ cells to CTLs. convert TH2 cells to TH1 cells. convert B cells to T cells.
activate CD8+ cells to CTLs.
Activation of C3a results in increased blood vessel permeability. attraction of phagocytes. cell lysis. opsonization. acute inflammation.
acute inflammation.
Which of the following is used to treat shingles? penicillin fungicide sulfonamide trifluridine acyclovir
acyclovir
In the Southern blot technique, which of the following is NOT required? addition of a labeled probe to identify the gene of interest addition of heat-stable DNA polymerase to amplify DNA electrophoresis to separate fragments restriction enzyme digestion of DNA transfer of DNA to nitrocellulose
addition of heat-stable DNA polymerase to amplify DNA
Margination refers to dilation of blood vessels. the adherence of phagocytes to microorganisms. the movement of phagocytes through walls of blood vessels. the chemotactic response of phagocytes. adherence of phagocytes to the lining of blood vessels.
adherence of phagocytes to the lining of blood vessels.
The fimbriae of Neisseria gonorrhea and enteropathogenic E. coli are examples of adhesins. ligands. receptors. adhesins and ligands. adhesins, ligands, and receptors.
adhesins and ligands.
Phagocytosis is a process for engulfing large particles (>1μm). Which feature of antibodies will help to make particles larger, therefore enhancing phagocytosis? complement activation neutralization opsonization agglutination
agglutination
A reaction between antibody and particulate antigen is called a(n) precipitation reaction. immunofluorescence. agglutination reaction. complement fixation. neutralization reaction.
agglutination reaction.
Dinoflagellates are a type of unicellular __________. One genus of dinoflagellates is responsible for a foodborne disease called __________. algae; paralytic shellfish poisoning (PSP) protozoa; dysentery tapeworm; cysticercosis fungus; potato blight
algae; paralytic shellfish poisoning (PSP)
Which of the following techniques would allow you to easily differentiate between Staphylococcus and Enterococcus? simple stain genetic testing Gram stain all of the above
all of the above
Which of the following virulence factors could directly prevent phagocytosis and/or phagocytic degradation? M proteins capsules waxy lipids all of the above none of the above
all of the above
Which of the following antibiotics causes misreading of mRNA? oxazolidinone - prevents formation of 70S ribosome chloramphenicol - inhibits peptide bonds at 50S subunit tetracyclines - bind with 30S subunit aminoglycoside - changes shape of 30S units streptogamin - prevents release of peptide from 70S ribosome
aminoglycoside - changes shape of 30S units
Which of the following antimicrobial agents is recommended for use against fungal infections? polymyxin bacitracin cephalosporin amphotericin B penicillin
amphotericin B
Which of the following does histamine NOT directly cause? vasodilation smooth muscle contraction anaphylactic shock increased vascular permeability
anaphylactic shock
An anamnestic response is another name for primary response. another name for secondary response. the appearance of antibodies in serum. the term used to describe the production of antibodies from a plasma cell.
another name for secondary response.
Which antibodies will be in the serum of a person with blood type B, Rh+? anti-A, anti-B, anti-Rh anti-A anti-B, anti-Rh anti-B anti-A, anti-RhWhich of the following are used to determine relatedness between a donor and a recipient for transplants? HLA antigens. ABO blood group antigens. MHC antigens. HLA and MHC antigens. HLA, MHC, and ABO blood group antigens.
anti-A
All of the following are generally used in vaccines EXCEPT
antibodies
Serological testing is based on the fact that bacteria clump together when mixed with any antibodies. antibodies react specifically with an antigen. all bacteria have the same antigens. the human body makes antibodies against bacteria. antibodies cause the formation of antigens.
antibodies react specifically with an antigen.
Toxoid vaccines, such as the vaccines against diphtheria and tetanus, elicit a(n) immune complex. dendritic cell proliferation. antibody response against these bacterial toxins. antibody response against gram-positive bacteria. TC cell response.
antibody response against these bacterial toxins.
All of the following are components of the inflammatory process EXCEPT antibody synthesis. diapedesis. release of histamines and prostaglandins. chemotaxis. dilation of blood vessels.
antibody synthesis.
In immune complex reaction shown in the figure, what is the structure labeled "a"? antigen mast cell antibody neutrophil complement
antigen
Which item is from the patient in a direct ELISA test? substrate for the enzyme antigen antihuman immune serum antibodies against the antigen
antigen
The classical pathway for complement activation is initiated by lipid-carbohydrate complexes and C3. antigen-antibody reactions. C5-C9. factors released from damaged tissues. factors released from phagocytes.
antigen-antibody reactions.
Plasma cells are activated by a(n) antigen. memory cell. APC. T cell. B cell.
antigen.
The process of desensitization to prevent allergies involves the injection of increasing amounts of IgE. antihistamine. IgG. RhoGAM. antigen.
antigen.
The ability of some microbes, such as Trypanosoma or Giardia to alter their surface molecules and evade destruction by the hosts antibodies is called cytopathic effect. virulence. lysogenic conversion. cytocidal effect. antigenic variation.
antigenic variation.
Prior to drawing blood for a blood donation, the nurse will scrub the arm with a Betadine solution. This form of antimicrobial control would be called __________. sterilization antisepsis disinfection sanitization
antisepsis
Symptoms of disease differ from signs of disease in that symptoms are changes observed by the physician. always occur as part of a syndrome. are specific for a particular disease. are changes felt by the patient. None of the answers is correct.
are changes felt by the patient.
Transient microbiota differ from normal microbiota in that transient microbiota never cause disease. are always acquired by direct contact. are present for a relatively short time. are found in a certain location on the host. cause diseases.
are present for a relatively short time.
Gluteraldehydes are among the most effective chemical control agents because they __________. act as surfactants are useful in preserving food are oligodynamic are relatively safe, yet considered a sterilizing agent
are relatively safe, yet considered a sterilizing agent
Biochemical tests _________________. are visualized using microscopes are used to determine rate of growth are the most effective way to determine bacterial shape are the main methods used to identify unknown bacteria
are the main methods used to identify unknown bacteria
Which region of the skin supports the largest bacterial population? feet forearms scalp armpits All of these support similarly sized bacterial populations.
armpits
What type of immunity results from vaccination? innate immunity naturally acquired active immunity naturally acquired passive immunity artificially acquired active immunity artificially acquired passive immunity
artificially acquired active immunity
What type of immunity results from transfer of antibodies from one individual to a susceptible individual by means of injection? innate immunity naturally acquired active immunity naturally acquired passive immunity artificially acquired active immunity artificially acquired passive immunity
artificially acquired passive immunity
The normal function of the PrP protein in mammals is believed to be: assisting proteins in forming alpha-helices. assisting in normal membrane development and function. assisting proteins in forming beta-pleated sheets. assisting in normal synaptic development and function.
assisting in normal synaptic development and function.
We sometimes are able to generate antibodies (immune system proteins) that bind to and cover up some of the proteins on the outermost portion of a virus while it is in the bloodstream. This renders the virus unable to reproduce. Which step of viral replication are antibodies directly preventing? synthesis attachment uncoating assembly
attachment
Which of the following is the least likely vaccine against HIV? subunit glycoprotein protein core attenuated virus All of these vaccines are equally likely.
attenuated virus
BCG is a vaccine against Mycobacterium tuberculosis. The vaccine is composed of a live Mycobacterium bovis variant called bacillus of Calmette and Guérin. This is an example of which type of vaccine? toxoid vaccine inactivated whole agent vaccine attenuated whole agent vaccine subunit vaccine
attenuated whole agent vaccine
Patients can receive one of two different types of influenza vaccine, both of which use whole viruses. The nasal spray uses live virus and is an example of a(n) ________ vaccine, while the injection uses killed virus and is an example of a(n)___________ vaccine. attenuated whole agent, inactivated whole agent attenuated whole agent, subunit inactivated whole agent, attenuated whole agent subunit, attenuated whole agent
attenuated whole agent, inactivated whole agent
What type of vaccine is the live measles virus? nucleic acid vaccine subunit vaccine toxoid vaccine conjugated vaccine attenuated whole-agent vaccine
attenuated whole-agent vaccine
Live polio virus can be used in a(n) inactivated whole-agent vaccine. attenuated whole-agent vaccine. conjugated vaccine. subunit vaccine. toxoid vaccine.
attenuated whole-agent vaccine.
Immunodeficiencies are a result of all of the following EXCEPT autoimmune diseases. Hodgkin's disease. HIV infection. cyclosporine. DiGeorge syndrome.
autoimmune diseases.
Lamisil is an allylamine used to treat dermatomycoses. Lamisil's method of action is similar to that of echinocandins. griseofulvin. polymyxin B. azole antibiotics. bacitracin.
azole antibiotics.
In the figure, which structure is a complex virus? a b c d All of the structures are complex viruses.
b
You have isolated an aerobic gram-positive, endospore-forming bacterium that grows well on nutrient agar. To which of the following groups does it most likely belong? deltaproteobacteria phototrophic bacteria bacillales gammaproteobacteria The answer cannot be determined based on the information provided.
bacillales
Mebendazole is used to treat cestode infections. It interferes with microtubule formation; therefore, it would NOT affect bacteria. fungi. protozoa. human cells. helminths.
bacteria
Most of the available antimicrobial agents are effective against viruses. bacteria. fungi. protozoa. All of the answers are correct.
bacteria
Which of the following is NOT an example of microbial antagonism? bacteriocin production acid production by bacteria bacteria competing for nutrients bacteria causing disease bacteria occupying host receptors
bacteria causing disease
R-plasmids are most likely acquired via Check all that apply. transduction. transformation. bacterial conjugation. translation.
bacterial conjugation.
A new bacterial molecule is discovered. This molecule binds to an antibiotic and facilitates the binding of a phosphate group, thus inactivating the antibiotic. Which category best describes the mechanism of antibiotic resistance conferred by this molecule? altered porins bacterial enzymes rapid efflux of the antibiotic conjugation
bacterial enzymes
Fluoroquinolones are the treatment prescribed for otitis externa, which is due to a __________. bacterial infection parasitic infection viral infection fungal infection
bacterial infection
Which of the following pairs of terms is mismatched? bacteriostatic kills vegetative bacterial cells germicide - kills microbes virucide - inactivates viruses fungicide kills yeasts and molds sterilant destroys all living microorganisms
bacteriostatic kills vegetative bacterial cells
Which type of organism would NOT be included in the Domain Eukarya? protist ameba fungus bacterium
bacterium
All of the following substances are used to preserve foods EXCEPT biguanides. nisin. sodium nitrite. potassium sorbate. calcium propionate.
biguanides
Most bacteria reproduce by fragmentation. binary fission. mitosis. aerial hyphae. budding.
binary fission.
Numerical identification methods rely on a series of which kind of test to identify microorganisms? DNA base composition ELISA DNA fingerprinting biochemical testing
biochemical testing
Which of the following is NOT used as a criterion to classify viruses? morphology biochemical tests size number of capsomeres nucleic acid
biochemical tests
Patients with indwelling catheters are susceptible to infections because biofilms develop on catheters. bacteria cause infections. infections can be transmitted from other people. their immune systems are weakened. injected solutions are contaminated.
biofilms develop on catheters.
Bacteriophages and animal viruses do NOT differ significantly in which one of the following steps? biosynthesis uncoating attachment release penetration
biosynthesis
Which of the following disinfectants acts by disrupting the plasma membrane? bisphenols heavy metals soaps aldehydes halogens
bisphenols
A chill is a sign that body temperature is rising. blood vessels are dilating. body temperature is not changing. body temperature is falling. the metabolic rate is decreasing.
body temperature is rising.
All of the following are effective for destroying prions EXCEPT boiling. proteases. incineration. NaOH + autoclaving at 134°C. Each of the answers will destroy prions.
boiling
Botulism is caused by ingestion of a proteinaceous exotoxin; therefore, it can easily be prevented by filtering food. preventing fecal contamination of food. boiling food prior to consumption. not eating canned food. administering antibiotics to patients.
boiling food prior to consumption.
Which of the following physical methods of microbial control denatures proteins as a mechanism of action? incineration boiling or autoclaving osmotic pressure radiation
boiling or autoclaving
Graft-versus-host disease will most likely be a complication of a(n) bone marrow transplant. skin graft. corneal transplant. blood transfusion. Rh incompatibility between mother and fetus.
bone marrow transplant.
Which of the following diseases is NOT spread by droplet infection? the common cold tuberculosis diphtheria measles botulism
botulism
The mechanism whereby an enveloped virus leaves a host cell is called abduction. lysogeny. transduction. penetration. budding.
budding.
How do antifungal drugs such as miconazole and amphotericin B function? by disrupting the plasma membrane by inhibiting protein synthesis by interfering with the processes of DNA replication and transcription by inhibiting cell wall synthesis
by disrupting the plasma membrane
Assume a patient has influenza. During which time on the graph in the figure would the patient show the symptoms of the illness? a b c d e
c
In the figure, which letter on the graph indicates the patient's secondary response to an antigen? a b c d e
c
The figure shows a typical bacterial growth curve with the x-axis indicating the time (hrs) in culture, and the the y-axis indicating the log of the number of bacteria. In the figure, which section (or sections) shows a growth phase where the number of cells dying equals the number of cells dividing? a b c d a and c
c - stationary phase
In the figure, which areas are similar for all IgG antibodies? a and b a and c b and c c and d b and d
c and d
Which of the following is NOT utilized to culture viruses? embryonated eggs laboratory animals bacterial cultures culture media animal cell cultures
culture media
Which disease would be potentially propagated in an environment without functional plumbing and in which drinking water is contaminated with sewage? cholera yellow fever ringworm influenza
cholera
A nucleotide-altering chemical can be incorporated into the DNA, to cause a mispairing of bases. can cause double-stranded breaks in the DNA. can alter nitrogenous bases of DNA, resulting in incorrect base pairing. can slip in between stacked bases, causing bulges in the DNA structure.
can alter nitrogenous bases of DNA, resulting in incorrect base pairing.
Competent cells are cells that are killed by heat. are also considered "rough-strain" based on colony phenotype. have the ability to produce capsules. can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination.
can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination.
The most conclusive evidence that viruses cause cancers is provided by cancer following injection of cell-free filtrates. some liver cancer patients having had hepatitis. the presence of antibodies against viruses in cancer patients. treating cancer with antibodies. finding oncogenes in viruses.
cancer following injection of cell-free filtrates.
Which of the following is NOT caused by HSV-1? herpes gladiatorum herpes encephalitis cold sores herpes whitlow canker sores
canker sores
Pathogenic bacteria isolated from the respiratory or intestinal tracts of humans are capnophiles that prefer highly oxygenated growth conditions. strict aerobes that grow best in candle jars. capnophiles that grow best in carbon dioxide incubators. strict aerobes that grow best in reducing media. facultative anaerobes that require reducing media for growth.
capnophiles that grow best in carbon dioxide incubators.
Which of the following bacterial components would most likely result in B cell stimulation by T-independent antigens? plasmid ribosome pili flagellum capsule
capsule
Oncogenic viruses are lytic viruses that kill the host cell. are genetically unstable. have no effect on the host cell. cause tumors to develop. cause acute infections.
cause tumors to develop.
Which of the following characteristics are shared by Enterococcus and Streptococcus? cell arrangement growth patterns on blood agar found on/in healthy carriers none of the above
cell arrangement
Which of the following is a method of vertical gene transmission? conjugation transduction cell division transformation
cell division
Lysozyme and the antibiotic penicillin have similar mechanisms of action in that they both cause damage to the bacterial DNA. ribosomes. cell wall. cell membrane. capsule.
cell wall.
Which of the following does NOT contribute to the symptoms of a fungal disease? capsules allergic response of the host toxins metabolic products cell walls
cell walls
Which of the following is mismatched? pus tissue debris and dead phagocytes in a white or yellow fluid diapedesis movement of leukocytes between capillary walls cells out of blood and into tissue chemotaxis chemical degradation inside a phagolysosome scab dried blood clot over injured tissue abcess a cavity created by tissue damage and filled with pus
chemotaxis chemical degradation inside a phagolysosome
The process by which a phagocyte moves toward a chemical signal at the site of an infection is called exocytosis. elimination. digestion. adherence. chemotaxis.
chemotaxis.
An eight-year-old girl has scabs and pus-filled vesicles on her face and throat. Three weeks earlier she had visited her grandmother, who had shingles. What infection does the eight-year-old have? measles fever blisters rubella scabies chickenpox
chickenpox
A patient has pus-filled vesicles and scabs on her face, throat, and lower back. She most likely has chickenpox. smallpox. rubella. mumps. measles.
chickenpox.
Which of the following substances is used for surgical hand scrubs? phenol glutaraldehyde chlorhexidine chlorine bleach soap
chlorhexidine
Evaluate the following chemical agents in regard to the effective use against endospores and mycobacteria. In a clinical situation where it is essential to control microbial growth that includes both mycobacteria and endospores, which chemical agent would be the most effective to guarantee the broadest disinfection? chlorines iodine phenolics alcohols
chlorines
Organisms once classified as protists are now being divided into which of the following? clades strains clones species
clades
Which of the following statements is NOT a possible outcome of antigen-antibody reaction? ADCC clonal deletion agglutination opsonization activation of complement
clonal deletion
An example of a latent viral infection is influenza. subacute sclerosing panencephalitis. cold sores. smallpox. mumps.
cold sores.
The structures of the influenza drug Tamiflu and sialic acid, the substrate for influenza viruss neuramidase, are shown in the figure. What is the method of action of Tamiflu? prevents synthesis of virus spikes competitive inhibition inhibits plasma membrane synthesis inhibits cell wall synthesis inhibits synthesis of neuramidase
competitive inhibition
After ingesting a pathogen, lysosomal enzymes produce all of the following EXCEPT H2O2. OH•. complement. O2-. HOCl.
complement
Which of the following is found normally in serum? complement histamine interferon leukocytosis-promoting factor TLRs
complement
A reaction that uses the absence of hemolysis of red blood cells to indicate an antigen-antibody reaction is called a(n) immunofluorescence. precipitation reaction. complement fixation. neutralization reaction. agglutination reaction.
complement fixation.
The symptoms of an immune complex reaction are due to phagocytosis. destruction of the antigen. complement fixation. cytokines. antibodies against self.
complement fixation.
A culture medium consisting of agar, peptone, and beef heart is a chemically defined medium. reducing medium. selective medium. differential medium. complex medium.
complex medium.
Rheumatoid arthritis is due to deposition of complement in joints. IgA antibodies in joints. IgG and IgA complexes in joints. IgD and IgE complexes in joints. complexes of IgM and IgG and also complement in joints.
complexes of IgM and IgG and also complement in joints.
Haemophilus capsule polysaccharide plus diphtheria toxoid is a(n) inactivated whole-agent vaccine. attenuated whole-agent vaccine. conjugated vaccine. subunit vaccine. toxoid vaccine.
conjugated vaccine.
When aerosols containing pathogens spread disease from a distance of less than one meter, it is considered vector transmission. contact transmission. airborne transmission. waterborne transmission.
contact transmission.
A transducing phage contains fragments of the host chromosome instead of the viral genome. is a lysogenic bacteriophage. has a viral coat made of host proteins. cannot infect new host cells.
contains fragments of the host chromosome instead of the viral genome.
Continuous cell lines differ from primary cell lines in that continuous cell lines can be maintained through an indefinite number of generations. continuous cell lines always have to be re-isolated from animal tissues. viruses can be grown in continuous cell lines. continuous cell lines are from human embryos. continuous cell lines are derived from primary cell lines.
continuous cell lines can be maintained through an indefinite number of generations.
The development of vaccines is considered the single most important application of immunology. What are the benefits associated with vaccinations? Select all that apply. control of viral disease herd immunity eradication of disease protection during travels
control of viral disease herd immunity eradication of disease
The life cycle of the fish tapeworm is similar to that of the beef tapeworm. Which of the following is the most effective preventive measure? cooking fish before eating not swimming in fish-infested waters wearing gloves while handling fish salting fish before eating refrigerating stored fish
cooking fish before eating
The damage caused by ultraviolet radiation is repaired by DNA replication. never repaired. repaired during translation. repaired during transcription. cut out and replaced.
cut out and replaced.
The term dermatophyte is typically used for fungi that cause which of the following? cutaneous mycoses opportunistic infections systemic mycoses subcutaneous mycoses
cutaneous mycoses
The encysted larva of the beef tapeworm is called a metacercaria. cysticercus. proglottid. redia. cercaria.
cysticercus.
Superantigens produce intense immune responses by stimulating lymphocytes to produce interferons. cytokines. endotoxins. leukocidins. exotoxins.
cytokines.
Symptoms of delayed cell-mediated reactions are due to antigens. IgE antibodies. IgG antibodies. neutrophils. cytokines.
cytokines.
An exotoxin that has the ability to kill or damage host cells is referred to as a(n) enterotoxin. A-B toxin. neurotoxin. superantigen. cytotoxin.
cytotoxin
The substrate for transpeptidase used to synthesize peptidoglycan is shown in the figure. Which of the drugs shown would inhibit peptidoglycan synthesis? a b c d e
d
the figure shows the incidence of influenza during a typical year. Which letter on the graph indicates the endemic level? a b c d The answer cannot be determined based on the information provided.
d
Predict which of the following outcomes would result from taking an antihistamine. Select all that apply. decreased permeability of blood vessels decreased histamine-based stimulation of cells decreased mucus secretions decreased stimulation of mast cells decreased contraction of respiratory smooth muscles increased breakdown of the histamine molecule
decreased permeability of blood vessels decreased histamine-based stimulation of cells decreased mucus secretions
pplication of heat to living cells can result in all of the following EXCEPT breaking of hydrogen bonds. decreased thermal death time. damage to nucleic acids. denaturation of enzymes. alteration of membrane permeability.
decreased thermal death time.
Bacterium Portal of Entry ID50 Staphylococcus aureus Wound <10 Staphylococcus aureus Wound + Ampicillin 300 the table shows the ID50 for Staphylococcus aureus in wounds with and without the administration of ampicillin before surgery. Based on the data, the administration of ampicillin before surgery increases the risk of staphylococcal infection. decreases the risk of staphylococcal infection. has no effect on risk of infection. replaces tetracycline. The answer cannot be determined based on the information provided.
decreases the risk of staphylococcal infection.
Several inherited deficiencies in the complement system occur in humans. Which of the following would be the MOST severe? deficiency of C3 deficiency of C5 deficiency of C6 deficiency of C7 deficiency of C8
deficiency of C3
A positive tuberculin skin test is an example of delayed cell-mediated immunity. psoriasis. innate immunity. autoimmunity. acute contact dermatitis.
delayed cell-mediated immunity.
A researcher has performed a prospective study on the disease tetanus. To which specific kind of epidemiological study is this referring? case control descriptive prodromal analytical experimental
descriptive
Thymic selection destroys CD4+ cells that attack self. destroys MHC molecules. destroys T cells that do not recognize self-molecules of MHC. destroys B cells that make antibodies against self. activates B cells.
destroys T cells that do not recognize self-molecules of MHC.
Chemotherapy to inhibit the progression of HIV infection utilizes all of the following mechanisms EXCEPT prohibition of viral integration into host cell DNA. inhibition of viral proteases. blockage of viral attachment. destruction of viral ribosomes. termination of viral DNA.
destruction of viral ribosomes.
Direct fluorescent-antibody techniques are frequently used to __________. produce monoclonal antibodies detect microorganisms in a clinical sample detect soluble antigens via the formation of aggregates detect antibodies in a clinical sample
detect microorganisms in a clinical sample
An ELISA for Hepatitis C has 95 percent sensitivity and 90 percent specificity. This means that the test detects 90 percent of the true positive samples and has 5 percent false positive results. detects 95 percent of the true positive samples and has 90 percent false positive results. detects 5 percent of the true positive samples and has 10 percent false positive results. detects 95 percent of the true positive samples and has 10 percent false positive results. detects 5 percent of the true positive samples and has 90 percent false positive results.
detects 95 percent of the true positive samples and has 10 percent false positive results.
Which of the following is an advantage of the standard plate count? can be used to count heat-sensitive bacteria can readily count cells that form aggregates can be performed on very dilute samples, such as lake water determines the number of viable cells provides immediate results
determines the number of viable cells
The Human Genome Project, which was completed in 2003, was focused on finding a cure for all human genetic disorders. determining all of the proteins encoded by the human genome. determining the nucleotide sequence of the entire human genome. cloning all of the genes of the human genome. identifying all of the genes in the human genome.
determining the nucleotide sequence of the entire human genome.
Bacteriophages derive all of the following from the host cell EXCEPT nucleotides. lysozyme. ATP. amino acids. tRNA.
lysozyme.
Which of the following is NOT a characteristic of spirochetes? easily observed with brightfield microscopy possess an axial filament helical shape gram-negative found in the human oral cavity
easily observed with brightfield microscopy
A primary difference between cyanobacteria and purple and green phototrophic bacteria is energy source. electron donor for CO2 reduction. color. cell type. cell wall type.
electron donor for CO2 reduction.
The nonsulfur photosynthetic bacteria use organic compounds as energy sources. carbon sources. electron donors to reduce CO2. oxygen sources. electron acceptors.
electron donors to reduce CO2.
Foreign DNA can be inserted into cells using a variety of different methods. Which method involves the formation of microscopic pores in the cell's membrane? electroporation protoplast fusion heat shock transformation
electroporation
Which of the following is the most effective control for malaria? vaccination eliminate Anopheles treating patients eliminate the intermediate host None of these is an effective control.
eliminate Anopheles
The following choices list several types of diseases, along with factors that may contribute to their emergence. Which disease and associated factor do NOT match? emergence of avian influenza A (H5N1): use of antibiotics increased incidence of malaria: global warming Increased incidence of Lyme disease: increases in deer populations spread of cholera to new regions: modern travel
emergence of avian influenza A (H5N1): use of antibiotics
A possible complication of chickenpox is congenital rubella syndrome. subacute sclerosing panencephalitis. fever blisters. encephalitis. macular rash.
encephalitis.
Malaria is an infectious disease caused by infection with a protozoan. In certain tropical regions, malaria is constantly present. We would say that malaria is a(n) _________ disease in these regions. sporadic endemic epidemic pandemic
endemic
If a disease occurs at a fairly stable rate, it is said to be endemic. epidemic. pandemic. sporadic.
endemic.
You have isolated a gram-positive rod. What should you do next? flagella stain enterotube endospore stain Gram stain lactose fermentation
endospore stain
Patients developed inflammation a few hours following eye surgery. Instruments and solutions were sterile, and the Limulus assay was positive. The patients inflammation was due to viral infection. bacterial infection. endotoxin. exotoxin. The answer cannot be determined based on the information provided.
endotoxin.
Bacteria such as E. coli and Salmonella produce invasins that bind host cells, thus causing the cells to release cytokines. engulf the bacteria. produce iron-binding proteins. release TNF. destroy the bacteria.
engulf the bacteria.
Most pathogens that gain access through the skin can penetrate intact skin. must adhere first while their invasive factors allow them to penetrate. just infect the skin itself. must be injected. enter through hair follicles and sweat ducts.
enter through hair follicles and sweat ducts.
Biochemical tests are used to determine nucleic acid-base composition. staining characteristics. amino acid sequences. enzymatic activities. All of the answers are correct.
enzymatic activities.
In a direct ELISA test to screen for drugs in a patients urine, what is the third step in the test process? enzyme-labeled antibodies against the drug being tested the patients urine sample antibody against the drug being tested substrate for the enzyme
enzyme-labeled antibodies against the drug being tested
If one is examining a blood smear from a patient with a parasitic worm infection, which of the following leukocytes would be found in increased numbers (as opposed to a blood smear from a normal patient NOT infected with worms)? basophils lymphocytes eosinophils monocytes
eosinophils
Which of the following is involved in resistance to parasitic helminths? basophils lymphocytes monocytes neutrophils eosinophils
eosinophils
The graph in the figure shows the incidence of polio in the United States. The period between 1945 and 1955 indicates a(n) pandemic. epidemic level. endemic level. communicable disease. sporadic infection.
epidemic level.
Which of the following definitions is INCORRECT? endemic: a disease that is constantly present in a population incidence: number of new cases of a disease pandemic: a disease that affects a large number of people in the world in a short time sporadic: a disease that affects a population occasionally epidemic: a disease that is endemic across the world
epidemic: a disease that is endemic across the world
The science that deals with when diseases occur and how they are transmitted is called morbidity and mortality. ecology. communicable disease. public health. epidemiology.
epidemiology.
Twenty-five people developed symptoms of nausea, vomiting, and diarrhea three to six hours after attending a church picnic where they ate a ham and green bean casserole with cream sauce. The most likely cause of this case of food intoxication is staphylococcal enterotoxin. botulinum toxin. erythrogenic toxin. aflatoxin. cholera toxin.
erythrogenic toxin.
Which of the following would be selective against the tubercle bacillus? vancomycin - inhibits peptidoglycan synthesis ethambutol - inhibits mycolic acid synthesis bacitracin - inhibits peptidoglycan synthesis streptomycin - inhibits protein synthesis streptogramin - inhibits protein synthesis
ethambutol - inhibits mycolic acid synthesis
Which of the following chemical agents is used for sterilization? chlorine ethylene oxide phenolics soap alcohol
ethylene oxide
ADCC is a process that is most effective in destroying bacterial toxins. eukaryotic pathogens. virus-infected host cells. extracellular viruses. bacterial pathogens.
eukaryotic pathogens.
Bacteria that can grow in the presence or absence of oxygen (O2) are called __________. facultative anaerobes obligate anaerobes obligate aerobes microaerophiles
facultative anaerobes
Which of the following are found primarily in the intestines of humans? gram-negative aerobic rods and cocci gram-positive cocci aerobic, helical bacteria facultatively anaerobic gram-negative rods endospore-forming rods
facultatively anaerobic gram-negative rods
All of the following are affects of histamine EXCEPT pain. redness. swelling. vasodilation. fever.
fever
Which type of bacterial enzyme helps spread Streptococcus pyogenes by digesting blood clots? fibrinolysin coagulase collagenase hyaluronidase
fibrinolysin
Which of the following methods used to count microbes is correctly matched as direct or indirect? plate count--indirect measurement filtration--direct method dry weight--direct measurement turbidity--direct method
filtration--direct method
Which of the following uses fluorescent-labeled antibodies? agglutination neutralization flow cytometry complement fixation precipitation
flow cytometry
Which compound would be the most useful to treat candidiasis? uracil thymine guanine flucytosine penicillin
flucytosine
Which technique is often used to determine the identity and abundance of microorganisms in an environment? (This technique is particularly useful because it does not require culture.) fluorescent in situ hybridization (FISH) ribotyping nucleic acid hybridization DNA chips
fluorescent in situ hybridization (FISH)
The antimicrobial effects of AMPs include all of the following EXCEPT inhibition of phagocytosis. destruction of nucleic acids. inhibition of cell wall synthesis. lysis of bacterial cells. pore formation in bacterial membranes.
inhibition of phagocytosis.
Which of the following methods of action would be bacteriostatic? injury to plasma membrane competitive inhibition with DNA gyrase inhibition of cell wall synthesis inhibition of protein synthesis competitive inhibition with folic acid synthesis
inhibition of protein synthesis
Bacteriophage replication differs from animal virus replication because only bacteriophage replication involves adsorption to specific receptors. replication of viral nucleic acid. lysis of the host cell. assembly of viral components. injection of naked nucleic acid into the host cell.
injection of naked nucleic acid into the host cell.
Mucous membranes are a part of innate defense. cell-mediated immunity. the complement system. adaptive defense. humoral immunity.
innate defense.
CD4+ T cells are activated by complement. interaction between CD4+ and MHC II. cytokines released by dendritic cells. interaction between TCRs and MHC II. cytokines released by B cells.
interaction between CD4+ and MHC II.
The antibiotic tetracycline binds to the 30S subunit of the ribosome, as shown in the figure. The effect is to stop the ribosome from moving along the mRNA. prevent attachment of DNA. interfere with the attachment of the tRNA to mRNA-ribosome complex. prevent peptide bond formation. prevent transcription.
interfere with the attachment of the tRNA to mRNA-ribosome complex.
Each of the following is an effect of complement activation EXCEPT increased phagocytic activity. bacterial cell lysis. opsonization. increased blood vessel permeability. interference with viral replication.
interference with viral replication.
If a larva of Echinococcus granulosus is found in humans, humans are the infected host. reservoir. intermediate host. definitive host. None of the answers is correct.
intermediate host.
What do tapeworms eat? host tissues plant matter intestinal bacteria intestinal contents red blood cells
intestinal contents
Biological transmission differs from mechanical transmission in that biological transmission involves fomites. works only with noncommunicable diseases. requires an arthropod. involves specific diseases. requires direct contact.
involves specific diseases.
An iodophor is a(n) phenol. agent that reduces oxygen. form of formaldehyde. iodine mixed with a surfactant. quaternary ammonium compound.
iodine mixed with a surfactant.
A recombinant cell donates DNA into a new cell. is the result of a cell dividing. is a cell that receives DNA from an outside source and incorporates it into its own.
is a cell that receives DNA from an outside source and incorporates it into its own.
A bacterial species differs from a species of eukaryotic organisms in that a bacterial species is a population of cells with similar characteristics. breeds with its own species. has a limited geographical distribution. does not breed with other species. can be distinguished from other bacterial species.
is a population of cells with similar characteristics.
Ethylene oxide is a sterilizing agent. requires high heat to be effective. is the active chemical in household bleach. is a good antiseptic. is not sporicidal.
is a sterilizing agent.
Streptomyces differs from Actinomyces because Streptomyces produces conidia. makes antibiotics. forms filaments. is a strict aerobe. is a bacterium.
is a strict aerobe.
Antigen processing and presentation is only accomplished by bacterial cells. is a way for viruses to infect cells. is a way for a cell to give information about its activities. is the way foreign cells engulf macrophages.
is a way for a cell to give information about its activities.
Innate immunity involves a memory component. involves T cells and B cells. is nonspecific and present at birth. is slower than adaptive immunity in responding to pathogens. provides increased susceptibility to disease.
is nonspecific and present at birth.
A silent mutation is so named because __________. it causes a frameshift, thus altering protein structure it results from the deletion of DNA, thus silencing the gene it results in a premature termination of the amino acid sequence it has no effect on the overall amino acid sequence
it has no effect on the overall amino acid sequence
All of the following are false regarding Herceptin EXCEPT it neutralizes the growth factor EGF. it is an endotoxin that stimulates TNF by macrophages. it is used to treat some breast cancer patients. it is a vaccine to prevent the development of cancer. it acts as an immunotoxin to target and kill cancer cells.
it is used to treat some breast cancer patients.
All of the following increase blood vessel permeability EXCEPT kinins. prostaglandins. leukotrienes. histamine. lysozymes.
lysozymes.
All of the following are true of hypersensitivity EXCEPT it requires previous exposure to an antigen. it is due to an altered immune response. it occurs when an individual is exposed to an allergen for the first time. it occurs in the presence of an antigen. it is synonymous with "allergy."
it occurs when an individual is exposed to an allergen for the first time.
In the presence of penicillin, a cell dies because it plasmolyzes. its contents leak out. it lacks a cell wall. it lacks a cell membrane. it undergoes lysis.
it undergoes lysis.
Penicillin was considered a "miracle drug" for all of the following reasons EXCEPT it kills bacteria. it does not affect eukaryotic cells. it inhibits gram-positive cell wall synthesis. it has selective toxicity. it was the first antibiotic.
it was the first antibiotic.
Burkholderia was reclassified from the gammaproteobacteria to the betaproteobacteria because it causes melioidosis. it grows in disinfectants. it is a gram-negative rod. it causes infections in cystic fibrosis patients. its rRNA sequence is similar to that of Neisseria.
its rRNA sequence is similar to that of Neisseria.
Mycoplasmas differ from other bacteria in that they lack a cell wall. grow inside host cells. are acid-fast. are gram-negative. are motile.
lack a cell wall.
Actinomycetes differ from fungi in that actinomycetes are decomposers. lack a membrane-bounded nucleus. cause disease. require light. are chemoheterotrophs.
lack a membrane-bounded nucleus.
Giardia and Trichomonas are unusual eukaryotes because they are motile. lack mitochondria. do not produce cysts. do produce cysts. lack nuclei.
lack mitochondria.
A disease in which the causative agent remains inactive for a time before producing symptoms is referred to as subclinical. acute. subacute. zoonotic. latent.
latent
Some viruses, such as human herpesvirus 1, infect a cell without causing symptoms. These are called phages. lytic viruses. unconventional viruses. slow viruses. latent viruses.
latent viruses.
The alternative pathway for complement activation is initiated by antigen-antibody reactions. lipid-carbohydrate complexes and C3. factors released from phagocytes. factors released from damaged tissues. C5-C9.
lipid-carbohydrate complexes and C3.
Focal infections initially start out as systemic infections. bacteremia. sepsis. septicemia. local infections.
local infections.
A patient enters the emergency room with itchy, swollen hives. This is an example of a ___________ allergic response called __________. localized; asthma systemic; urticaria localized; anaphylaxis localized; urticaria
localized; urticaria
During which growth phase will gram-positive bacteria be most susceptible to penicillin? log phase lag phase The culture is equally susceptible during all phases. death phase stationary phase
log phase
Which of the following phases of the bacterial growth curve is matched with the correct definition? log phase--the phase where organisms are actively dividing and the generation time is constant death phase--the phase where the curve is flat; microbial deaths balance the number of new cells stationary phase--the phase where cells are not dividing very rapidly as they acclimatize to a new environment lag phase--the phase where the death of organisms exceeds the creation of new cells and the curve declines
log phase--the phase where organisms are actively dividing and the generation time is constant
Kelly learns that the diagnosis of HPV may rely on the presence of viral DNA. Other infectious agents can be diagnosed based on immunologic responses. Which of the following represents an immunologic-based diagnostic test? Select all that apply. fluorescent-antibody techniques agglutination reactions precipitation reactions polymerase chain reaction (PCR)
luorescent-antibody techniques agglutination reactions precipitation reactions
The initial symptom of HIV infection is lymphadenopathy significant weight loss appearance of thrush. loss of T cells. high viral load.
lymphadenopathy
Activation of C5-C9 results in lysis of microbial cells. fixation of complement. phagocytosis. activation of C3. inflammation.
lysis of microbial cells.
In which intracellular compartment would you expect most of the digestive enzymes involved in pathogen destruction to be found? phagosome macrophage lysosome phagocytosis
lysosome
Phagocytes utilize all of the following to optimize interaction with microorganisms EXCEPT complement. lysozyme. chemotaxis. trapping a bacterium against a rough surface. opsonization.
lysozyme
Which of the following does not occur during RNA processing? Segments of RNA that do code for the protein are reconnected. A modified guanine nucleotide is added to the beginning of the RNA strand as a cap. Segments of the RNA strand that do not actually code for the protein are removed. Adenine nucleotides are added to the end of the RNA strand, forming a tail. mRNA attaches to the small subunit of a ribosome.
mRNA attaches to the small subunit of a ribosome.
Which of the following best describes the flow of information in cells? Ribosomes make proteins by randomly linking amino acids together. mRNA is made by copying specific regions of DNA called genes. Ribosomes use mRNA as instructions, which provide a code specifying the order of amino acids in a protein. DNA acts as a messenger. It binds to a ribosome and provides instructions for making protein. DNA is converted to RNA, which is then converted to protein.
mRNA is made by copying specific regions of DNA called genes. Ribosomes use mRNA as instructions, which provide a code specifying the order of amino acids in a protein.
Which of the following is a correct statement about mRNA? mRNA is transcribed from DNA in the cytoplasm. mRNA includes a cap that consists of extra adenine nucleotides. mRNA moves from the nucleus to the cytoplasm following RNA processing. mRNA binds directly to amino acids during translation. Segments of mRNA that code for protein are removed before translation.
mRNA moves from the nucleus to the cytoplasm following RNA processing.
The reaction catalyzed by reverse transcriptase is tRNA → mRNA. mRNA → protein. DNA → mRNA. mRNA → cDNA. DNA → DNA.
mRNA → cDNA.
Transcription produces which of the following? mRNA rRNA tRNA mRNA and tRNA mRNA and rRNA mRNA, tRNA, and rRNA are all produced by transcription.
mRNA, tRNA, and rRNA are all produced by transcription.
Which of the following antibiotics does NOT interfere with cell wall synthesis? macrolides vancomycin cephalosporins semisynthetic penicillins natural penicillins
macrolides
Which of the following exhibits the highest phagocytic activity? erythrocytes eosinophils macrophages neutrophils basophils
macrophages
The lectin pathway for complement action is initiated by gram-positive cell walls. gram-negative cell walls. lectins of the microbe. mannose on the surface of microbes. mannose on host membranes.
mannose on the surface of microbes.
A commensal bacterium does not infect its host. does not receive any benefit from its host. may also be an opportunistic pathogen. is beneficial to its host. is beneficial to, and does not infect, its host.
may also be an opportunistic pathogen.
Koplik spots are a diagnostic indicator of fifth disease. rubella. smallpox. measles. chickenpox.
measles.
During asymptomatic phase I of HIV disease, HIV infection is diagnosed by testing for seroconversion. measuring antibodies against HIV. counting CD8+ T cells. counting CD4+ T cells. measuring viral RNA.
measuring viral RNA.
Which of the following is the best method to sterilize heat-labile solutions? autoclave dry heat freezing membrane filtration pasteurization
membrane filtration
Certain cancer cells have ABC transport molecules at the cell surface. These transporters use energy from ATP to move chemotherapeutic agents out of the cell. Which of the following do you think these transporters are most closely related to? beta-lactamase membrane pumps conjugation pilus altered porins
membrane pumps
All of the following are methods of avoiding host antibodies EXCEPT inducing endocytosis. invasins. antigenic changes. IgA proteases. membrane-disrupting toxins.
membrane-disrupting toxins.
Microbes have very narrow optimum temperature ranges. Which of the following classifications of microbes are most likely to cause human disease, based on temperature requirements? mesophiles hyperthermophiles psychrophiles thermophiles
mesophiles
Which of the following is NOT a direct method to measure microbial growth? standard plate count most probable number (MPN) direct microscopic count filtration metabolic activity
metabolic activity
Which of the following applications of recombinant DNA technology is NOT controversial? biological weapons development genetic food modification metagenomics genetic screening
metagenomics
All of the following are characteristic of the Group A beta-hemolytic streptococci EXCEPT hyaluronidase production. the ability to dissolve blood clots. methicillin resistance. M proteins. the ability to damage cell membranes.
methicillin resistance.
All of the following are methods of food preservation EXCEPT microwaves. high pressure. desiccation. osmotic pressure. ionizing radiation.
microwaves.
Scabies is a skin disease caused by a protozoan. bacterium. slow virus. mite. prion.
mite.
Microbial control methods usually target any of the following microbial structuresEXCEPT which one? mitochondria nucleic acids microbial proteins plasma membrane permeability
mitochondria
Palivizumab is used to treat respiratory syncytial virus disease. This antiviral drug is a(n) vaccine. monoclonal antibody. nucleoside analog. immunosuppressive. toxoid.
monoclonal antibody.
Macrophages arise from which of the following? monocytes basophils eosinophils neutrophils lymphocytes
monocytes
Below are paired items referring to the heartworm Dirofilaria immitis. Which of the pairs is mismatched? mosquito - definitive host dog - definitive host mosquito - vector dog - sexual reproduction None of the pairs is mismatched.
mosquito - definitive host
Dengue fever is transmitted by which of the following? fleas sucking lice mosquitoes mites and ticks
mosquitoes
Which non-specific defense mechanism is mismatched with its associated body structure or body fluid? very acidic pH stomach keratin and tightly packed cells skin mucociliary escalator intestines lysozyme tears and saliva cerumen and sebum ear
mucociliary escalator intestines
The most frequently used portal of entry for pathogens is the mucous membranes of the gastrointestinal tract. mucous membranes of the respiratory tract. parenteral route. skin. All of these portals are used equally.
mucous membranes of the respiratory tract.
Polio is transmitted by ingestion of water contaminated with feces containing polio virus. What portal of entry does polio virus use? skin only parenteral only mucous membranes only skin and parenteral skin, parenteral, and mucous membranes
mucous membranes only
A researcher creates an antibiotic that binds to a protein present only on B. anthracis (the causative agent of anthrax), lysing the cell from the outside. After a couple of years using this antibiotic, some resistant organisms are found. Which of the following best outlines the mechanism for development of this resistance? cell division of B. anthracis → altered target → resistant bacterium mutation in B. anthracis → altered porins → resistant bacterium cell division of B. anthracis → altered porins → resistant bacterium mutation in B. anthracis → altered target → resistant bacterium
mutation in B. anthracis → altered target → resistant bacterium
Which one of the following is most resistant to chemical biocides? gram-positive bacteria viruses with lipid envelopes protozoan cysts gram-negative bacteria mycobacteria
mycobacteria
Which of the following cells is NOT an APC? natural killer cells dentritic cells macrophages immature B cells None of the answers is correct; all of these are APCs.
natural killer cells
An individual may be exposed to a pathogen and become infected without actually getting sick. This is known as a subclinical infection. Even in subclinical infections, the individual's adaptive immune system can generate memory for the pathogen. What type of adaptive immunity is this? artificially acquired active immunity artificially acquired passive immunity naturally acquired passive immunity naturally acquired active immunity
naturally acquired active immunity
What type of immunity results from recovery from mumps? innate immunity naturally acquired active immunity naturally acquired passive immunity artificially acquired active immunity artificially acquired passive immunity
naturally acquired active immunity
Newborns' immunity due to the transfer of antibodies across the placenta is an example of innate immunity. naturally acquired active immunity. naturally acquired passive immunity. artificially acquired active immunity. artificially acquired passive immunity.
naturally acquired passive immunity.
A patient who has been hospitalized with uncontrolled muscle spasms has probably been infected with bacteria that secrete a(n) membrane disrupting toxin. neurotoxin. superantigen. enterotoxin.
neurotoxin.
The flu virus mutates fairly frequently. Its adhesive proteins change such that we have different "strains" of influenza each year. When a particular flu virus mutates such that its adhesive proteins change, which function of antibodies is disrupted? agglutination neutralization complement activation opsonization
neutralization
When an antibody binds to a toxin, the resulting action is referred to as apoptosis. agglutination. opsonization. neutralization. ADCC.
neutralization.
Thymine dimers result from mistakes by DNA polymerase. nucleoside analogs. nonionizing radiation. ionizing radiation.
nonionizing radiation.
While studying protein synthesis in the lab, you experimentally induce a mutation in a bacterium's DNA. You assess the proteins in the mutated bacterium and find that one of them is significantly shorter than its wild-type counterpart. Based on this information, what type of mutation did you induce? silent mutation deletion mutation nonsense mutation missense mutation
nonsense mutation
A base substitution that changes a codon coding for an amino acid to a stop codon is called a nonsense mutation. missense mutation. frameshift mutation. silent mutation.
nonsense mutation.
Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery. This is an example of a sporadic disease. nosocomial infection. latent infection. communicable disease. None of the answers is correct.
nosocomial infection.
What type of vaccine involves host synthesis of viral antigens? subunit vaccine nucleic acid vaccine toxoid vaccine attenuated whole-agent vaccine conjugated vaccine
nucleic acid vaccine
A DNA plasmid encoding a protein antigen from West Nile virus is injected into muscle cells of a horse. This is an example of a(n) conjugated vaccine. subunit vaccine. nucleic acid vaccine. attenuated whole-agent vaccine. live whole-agent vaccine.
nucleic acid vaccine.
Which of the following contributes to the virulence of a pathogen? numbers of microorganisms that gain access to a host evasion of host defenses toxin production numbers of microorganisms that gain access to a host and evasion of host defenses numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production
numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production
For which of the following types of microbes would a microbiologist use culture techniques for living host cells? capnophiles normal skin bacteria obligate intracellular organisms, such as chlamydia and viruses Campylobacteria sp.
obligate intracellular organisms, such as chlamydia and viruses
Dermatophytes are fungi that can infect the __________ because they can grow on/in __________. vagina; mucosal secretions oil glands; sebum mouth; saliva outer skin; keratin
outer skin; keratin
Warts are caused by poxvirus. herpesvirus. parvovirus. papillomavirus. Staphylococcus aureus.
papillomavirus.
Endotoxins are A-B toxins. part of the gram-negative cell wall. excreted from the cell. molecules that bind nerve cells. associated with gram-positive bacteria.
part of the gram-negative cell wall.
Consider various effects of moist and dry heat to control microbial growth. Which of the following methods would best reduce microbes without altering the taste and chemical composition of beer? pasteurization hot-air sterilization autoclaving boiling
pasteurization
Which of the following does NOT achieve sterilization? pasteurization ethylene oxide autoclave dry heat supercritical fluids
pasteurization
Which of the following is NOT a fungal infection? ringworm jock itch pediculosis thrush
pediculosis
Which of the following antimicrobial agents has the fewest side effects? tetracycline streptomycin erythromycin chloramphenicol penicillin
penicillin
The source of nutrients in nutrient agar is agar. nutrient. peptone and beef extract. peptone and NaCl. agar and NaCl.
peptone and beef extract.
Disinfection of water is achieved by all of the following EXCEPT copper sulfate. ozone. UV radiation. peracetic acid. chlorine.
peracetic acid.
Which one of the following causes transmembrane channels in target cells? hapten granzymes perforin IL-1 IL-2
perforin
The definition of lysogeny is phage DNA is incorporated into host cell DNA. when the burst time takes an unusually long time. the period during replication when virions are not present. lysis of the host cell due to a phage. attachment of a phage to a cell.
phage DNA is incorporated into host cell DNA.
A child falls and suffers a deep cut on her leg. The cut went through her skin and she is bleeding. Which of the following defense mechanisms will participate in eliminating contaminating microbes? normal skin flora mucociliary escalator acidic skin secretions phagocytosis in the inflammatory response lysozyme
phagocytosis in the inflammatory response
Mycobacterium tuberculosis is an intracellular pathogen of humans. After being ingested by a macrophage, it prevents formation of the ___________ by preventing fusion of the phagosome with the ___________________. opsonins, lysosome lysosome, opsonins phagolysosome, lysosome lysosome, phagolysosome
phagolysosome, lysosome
The number of T cells drops to below 200 cells/microliter in which phase of HIV infection? phase 1 asymptomatic phase initial phase phase 2 phase 3
phase 3
A clear area against a confluent "lawn" of bacteria is called a plaque. cell lysis. rash. phage. pock.
plaque
In the microscope, you observe multinucleated amoeboid cells with sporangia that form spores. This is a(n) plasmodial slime mold. tapeworm. Euglenozoa. ascomycete. cellular slime mold.
plasmodial slime mold.
Which of the following antibiotics is NOT bactericidal? aminoglycosides polyenes rifampins penicillin cephalosporins
polyenes
PCR stands for polymerase copy reaction. polymerase chain reaction. polymerization copying rapidly.
polymerase chain reaction.
Which of the following antibiotics is recommended for use against gram-negative bacteria? penicillin polymyxin bacitracin cephalosporin polyenes
polymyxin
Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides were removed, Vibrio would not produce cholera toxin. polypeptide B would not be able to enter the cells. Vibrio would bind to target cells. polypeptide A would enter the cells. polypeptide A would bind to target cells.
polypeptide B would not be able to enter the cells.
Borrelia is classified as a spirochete because it is aerobic. is a rod. is a pathogen. is transmitted by ticks. possesses an axial filament.
possesses an axial filament.
Which of the following is used to treat sporotrichosis? potassium iodide sulfonamide trifluridine penicillin acyclovir
potassium iodide
Which of the following are incorrectly matched? poxvirus fever blisters HHV-6 roseola parvovirus fifth disease herpes zoster shingles varicella-zoster chickenpox
poxvirus fever blisters
Which of the following is a test to determine the presence of soluble antigens in a patient's saliva? direct agglutination reaction passive agglutination reaction immunofluorescence neutralization reaction precipitation reaction
precipitation reaction
A reaction between an antibody and soluble antigen-forming lattices is called a(n) agglutination reaction. neutralization reaction. immunofluorescence. complement fixation. precipitation reaction.
precipitation reaction.
A viruss ability to infect an animal cell depends primarily upon the presence of receptor sites on the cell membrane. presence of pili on the host cell wall. type of viral nucleic acid. host cells ability to phagocytize viral particles. enzymatic activity of a host cell.
presence of receptor sites on the cell membrane.
If you were preparing nutrient agar at home and did not have an autoclave, what could you use to sterilize the nutrient agar? hydrogen peroxide pressure cooker at 121°C for 15 minutes bleach boiling for 1 hour oven at 121°C for 1 hour
pressure cooker at 121°C for 15 minutes
A drug binds to the ribosome as shown in the figure. The effect is to prevent transcription prevent the polypeptide from exiting the ribosome prevent peptide bond formation prevent ribosome formation prevent mRNA-ribosome binding
prevent peptide bond formation
Which of the following provides the specificity of the PCR reaction? primers heating to 94°C Taq polymerase separated DNA strands
primers
An infectious protein is a viroid. bacteriophage. prion. retrovirus. papovavirus.
prion.
Neutrophils with defective lysosomes are unable to attach to microorganisms and other foreign material. migrate. engulf microorganisms and other foreign material. undergo chemotaxis. produce toxic oxygen products.
produce toxic oxygen products.
More than half of our antibiotics are produced by fungi. produced by eukaryotic organisms. produced by bacteria. produced by Fleming. synthesized in laboratories.
produced by bacteria.
All of the following are effects of histamine EXCEPT isolation of an injurious agent. repair of damaged tissue. production of antibodies. destruction of an injurious agent. removal of an injurious agent.
production of antibodies.
Innate immunity includes all of the following EXCEPT activation of complement. inflammation. production of interferon. phagocytosis. production of antibody.
production of antibody.
Which of the following characterizes the Domain Bacteria? multicellular prokaryotic cells; ester linkages in phospholipids prokaryotic cells; ether linkages in phospholipids complex cellular structures eukaryotic cells; ester linkages in phospholipids
prokaryotic cells; ester linkages in phospholipids
Escherichia coli belongs to the actinomycetes. green sulfur bacteria. spirochetes. proteobacteria. gram-positive bacteria.
proteobacteria.
All of the following are protective factors of the skin and its secretions EXCEPT lysozyme production. salt. pyocyanin production. tightly packed cells. keratin.
pyocyanin production.
Ribosomes contain which of the following? mRNA, tRNA, and rRNA are all found as part of the ribosome. tRNA mRNA rRNA
rRNA
The phylogenetic classification of bacteria is based on gram reaction. rRNA sequences. habitat. cell morphology. diseases.
rRNA sequences.
Which of the following is an advantage of the direct microscopic count? can easily distinguish live from dead cells requires a large number of cells requires no incubation time can readily count organisms that are motile sample volume is unknown
requires no incubation time
The site of translation is the cell nucleus. the plasma membrane. ribosomes in the cell nucleus. ribosomes in the cell cytoplasm. the Golgi apparatus.
ribosomes in the cell cytoplasm.
Which of the following is a fungal zoonosis that can be transmitted by direct contact? Lyme disease tapeworm ringworm West Nile encephalitis
ringworm
A 9-month old baby with a macular rash is brought to the hospital. Parents report that the rash started on the face, spread to the rest of the body, and was preceded with coldlike symptoms. There are small reddish spots in the baby's mouth. What is the diagnosis? chickenpox smallpox rubeola shingles
rubeola
Exfoliative toxin is responsible for fever blisters. scalded skin syndrome. impetigo. thrush. otitis externa.
scalded skin syndrome.
Blood agar would be the culture medium of choice if one were testing a patient for which of the following? actinomycosis scarlet fever tuberculosis food poisoning
scarlet fever
Which of the following definitions is INCORRECT? primary infection: an initial illness acute: a short-lasting primary infection chronic: a disease that develops slowly and lasts for months secondary infection: a long-lasting illness inapparent: infection characteristic of a carrier state
secondary infection: a long-lasting illness
A culture medium on which only gram-positive organisms grow and a yellow halo surrounds Staphylococcus aureus colonies is called a(n) selective medium. differential medium. enrichment culture. selective and differential medium. differential and enrichment culture.
selective and differential medium.
Which of the following does NOT affect eukaryotic cells? antihelminthic drugs semisynthetic penicillins antiprotozoan drugs nucleotide analogs antifungal drugs
semisynthetic penicillins
Allergic contact dermatitis is due to IgE antibodies. IgG antibodies. activated macrophages. IgM antibodies. sensitized T cells.
sensitized T cells.
Endotoxins in sterile injectable drugs could cause no damage, because they are sterile. giant cell formation. infection. septic shock symptoms. nerve damage.
septic shock symptoms.
Koch observed Bacillus anthracis multiplying in the blood of cattle. What is this condition called? focal infection systemic infection local infection septicemia bacteremia
septicemia
Which of the following is classified as a latent disease? infectious mononucleosis influenza tuberculosis shingles
shingles
Which of the following may result from systemic anaphylaxis? immunodeficiency hives asthma shock hay fever
shock
The health of the patient is secondary to the health of the healthcare worker. should be the primary concern of the healthcare worker. is secondary to the health of co-workers in healthcare settings.
should be the primary concern of the healthcare worker.
All of the following are iron-binding proteins found in humans EXCEPT ferritin. hemoglobin. transferrin. siderophorin. lactoferrin.
siderophorin
A mutation that affects the genotype of the organism but not the phenotype is called a frameshift mutation. silent mutation. missense mutation. nonsense mutation.
silent mutation.
Which of the following correctly lists the current distribution of HIV infection and AIDS in order of DECREASING prevalence? sub-Saharan Africa, Latin America, Western Europe, Australia / New Zealand sub-Saharan Africa, Western Europe, Latin America, Australia / New Zealand Latin America, sub-Saharan Africa, Western Europe, Australia / New Zealand sub-Saharan Africa, Australia / New Zealand, Western Europe, Latin America
sub-Saharan Africa, Latin America, Western Europe, Australia / New Zealand
Which of the following is a basic type of vaccine? Select all that apply. subunit vaccine antitoxin vaccines live, attenuated vaccine nucleic acid vaccines
subunit vaccine live, attenuated vaccine nucleic acid vaccines
Which test involves placing samples of an UNKNOWN bacterium in saline, adding different antisera, and checking for clumping? Western blotting ELISA phage typing slide agglutination
slide agglutination
Which of the following is the best definition of epitope? specific regions on antigens that interact with perforins specific regions on antigens that interact with MHC class molecules specific regions on antigens that interact with antibodies specific regions on antigens that interact with T-cell receptors specific regions on antigens that interact with haptens
specific regions on antigens that interact with antibodies
All of the following bacteria are motile. Which does NOT have flagella? Salmonella Pseudomonas helical bacteria spirochetes Escherichia
spirochetes
Which of the following is a subcutaneous mycosis? tinea capitis. sporotrichosis. athletes foot. Buruli ulcer. erysipelas.
sporotrichosis.
Which of the following leads to all the others? toxemia staphylococcal infection TSST-1 sudden drop in blood pressure scalded skin syndrome
staphylococcal infection
Mice that are injected with only the R strain of Streptococcus pneumoniae are killed, because R strain cells are deadly. stay healthy, because their immune systems can kill this strain easily. become sick for prolonged periods of time.
stay healthy, because their immune systems can kill this strain easily.
IL-2, produced by TH cells, activates macrophages. causes phagocytosis. activates TC cells to CTLs. activates antigen-presenting cells.
stimulates TH cell maturation
Bacteria that cause periodontal disease have adhesins for receptors on streptococci that colonize on teeth. This indicates that streptococci cause periodontal disease. bacteria that cause periodontal disease adhere to gums and teeth. bacteria that cause periodontal disease adhere to teeth. streptococcal colonization is necessary for periodontal disease. streptococci get bacterial infections.
streptococcal colonization is necessary for periodontal disease.
For which of the following would growth on blood agar be a good diagnostic tool? staphylococci enterococci streptococci all Gram-positive cocci
streptococci
Which of the following drugs does NOT act by competitive inhibition? isoniazid streptomycin ethambutol trimethoprim sulfonamide
streptomycin
Which one of the following does NOT belong with the others? bacitracin monobactam penicillin cephalosporin streptomycin
streptomycin
Which of the following regions has the greatest distribution of HIV infection and AIDS in the world? South and Southeast Asia Latin America Eastern Europe and Central Asia sub-Saharan Africa North America
sub-Saharan Africa
A vaccine against HIV proteins made by vaccinia virus is a(n) conjugated vaccine. subunit vaccine. nucleic acid vaccine. inactivated whole-agent vaccine. toxoid vaccine.
subunit vaccine.
The ID50 is a measure of pathogenicity. the dose that will kill some of the test population. the dose that will cause an infection in some of the test population. the dose that will kill 50 percent of the test population. the dose that will cause an infection in 50 percent of the test population.
the dose that will cause an infection in 50 percent of the test population.
When a patient is treated with antibiotics, __________. mutations occur in all of the bacterial cells sensitive bacterial cells multiply uncontrollably the drug will kill or inhibit the growth of all of the sensitive bacterial cells the drug will kill or inhibit the growth of all of the resistant bacterial cells mutations will occur in the sensitive bacterial cells, but not in the resistant bacterial cells
the drug will kill or inhibit the growth of all of the sensitive bacterial cells
Expected prevalence of a disease is the total number of cases of a disease over a period of time. the expected occurrence of a disease based on past observations. the number of new cases of a disease over a period of time. the anticipated geographical spread of a disease based on past observances.
the expected occurrence of a disease based on past observations.
Which of the following factors is believed to limit the size of most bacterial cells? the availability of nitrogen in the environment the fact that nutrients must enter the cells by simple diffusion the ability to acquire oxygen for cell respiration the availability of carbon in the environment
the fact that nutrients must enter the cells by simple diffusion
The initial effect of ionizing radiation on a cell is that it causes base substitutions. bonding between adjacent thymines. the cells to get hot. DNA to break. the formation of highly reactive ions.
the formation of highly reactive ions.
The antimicrobial activity of chlorine is due to which of the following? the formation of ozone the formation of hypochlorous acid the formation of a hypochlorite ion disruption of the plasma membrane the formation of hydrochloric acid
the formation of hypochlorous acid
Phagocytosis is defined as the ingestion of solid material by a eukaryotic cell. the uptake of liquid material by a eukaryotic cell. cells of the immune system that ingest pathogens. the feeding of protozoans.
the ingestion of solid material by a eukaryotic cell.
Which of the following is an example of direct damage due to bacterial infection? the fever, nausea, and low blood pressure in a Salmonella infection the uncontrolled muscle contractions in Clostridium tetani infection the excessive secretion of fluids in a Vibrio cholera infection the invasion and lysis of intestinal cells by E. coli the hemolysis of red blood cells in a staphylococcal infection
the invasion and lysis of intestinal cells by E. coli
Which of the following is the best definition of generation time? the duration of log phase the length of time needed for lag phase the minimum rate of doubling the time needed for nuclear division the length of time needed for a cell to divide
the length of time needed for a cell to divide
Diapedesis is the migration of phagocytes through blood vessels to the site of tissue damage. the increase in the diameter of blood vessels. the production and release of chemicals during inflammation. the attachment of phagocytes to the walls of capillaries.
the migration of phagocytes through blood vessels to the site of tissue damage.
The yeast Candida albicans does not normally cause disease because of ______. other fungi parasitic bacteria the transient microbiota the normal microbiota
the normal microbiota
A differential cell count is used to determine each of the following EXCEPT the number of red blood cells. leukocytosis. leukopenia. the numbers of each type of white blood cell. the total number of white blood cells.
the number of red blood cells.
Both the innate and adaptive defenses of the immune system work to prevent disease. colonization by pathogens. penetration by invading pathogens. the penetration and colonization by pathogens, and the diseases they cause.
the penetration and colonization by pathogens, and the diseases they cause.
Which of the following is a xenograft? transplantation of a kidney from a woman to her twin sister. the replacement of a human's heart valve with a pig's heart valve transplantation of tissue from one area on a person's body to anther transplantation of a kidney from a woman to her older brother
the replacement of a human's heart valve with a pig's heart valve
In the figure, the arrow at time (c) indicates the time of exposure to the same antigen as at time (a). exposure to a new antigen. the primary response. the secondary response. the T-cell response.
the secondary response.
One of the most popular taxonomic tools is DNA fingerprinting to develop profiles of organisms. These profiles provide direct information about the presence of specific genes. enzymatic activities. protein composition. the similarities between nucleotide sequences. antigenic composition.
the similarities between nucleotide sequences.
The specificity of an antibody is due to its valence. the H chains. the L chains. the constant portions of the H and L chains. the variable portions of the H and L chains.
the variable portions of the H and L chains.
Protozoan and helminthic diseases are difficult to treat because their cells are structurally and functionally similar to human cells. they do not reproduce. they replicate inside human cells. they do not have ribosomes. they have more genes than bacteria.
their cells are structurally and functionally similar to human cells.
The eradication of smallpox was possible because it was a relatively mild disease. it occurs only in the tropics. there are no animal reservoirs of the virus. insect vectors were eliminated. it can be prevented with the same vaccine used to prevent chickenpox.
there are no animal reservoirs of the virus.
All of the following are characteristic of algae EXCEPT they may be unicellular or multicellular. they mostly live in aquatic habitats. some produce harmful toxins. they are classified as plants. most are photoautotrophs.
they are classified as plants.
All of the following are part of the mechanism of action of alpha and beta interferons EXCEPT they bind to the surface of uninfected cells. they are effective for long periods. they initiate manufacture of antiviral proteins. they initiate transcription. they disrupt stages of viral multiplication.
they are effective for long periods.
All of the following pertain to serological tests EXCEPT they can be used to diagnose various diseases. they can detect antibodies but not antigens. reactions can be detected by uptake of trypan blue by damaged cells. they are used to detect compatible tissues for transplantation. they are used to test for specific HLAs on lymphocytes.
they can detect antibodies but not antigens.
All of the following are true regarding NK cells EXCEPT they destroy infected body cells by phagocytosis. they are a type of lymphocyte. they have the ability to kill infected body cells and some tumor cells. they are found in tissues of the lymphatic system. they release toxic substances that cause cell lysis or apoptosis.
they destroy infected body cells by phagocytosis.
The cells of plasmodial slime molds can grow to several centimeters in diameter because they have organelles. they distribute nutrients by cytoplasmic streaming. they have a mouth to ingest nutrients. the large surface can absorb nutrients. they form spores.
they distribute nutrients by cytoplasmic streaming.
All of the following regarding "privileged sites" are true EXCEPT they include any tissue transplanted from a pig. they are rarely rejected. they do not have lymphatic vessels. they include corneal and brain tissue. they explain how animals tolerate pregnancies without rejecting the fetus.
they include any tissue transplanted from a pig.
Normal microbiota provide protection from infection in each of the following ways EXCEPT they produce lysozyme. they produce antibacterial chemicals. they make the chemical environment unsuitable for nonresident bacteria. they change the pH of the environment. they compete with pathogens for nutrients.
they produce lysozyme.
If a patient notices a healthcare worker not following suggested precautions, they should leave the healthcare facility immediately. they should immediately bring it to the attention of the healthcare worker. they should immediately wash their hands.
they should immediately bring it to the attention of the healthcare worker.
All of the following are transmitted via the respiratory route EXCEPT measles. tinea. rubella. chickenpox. smallpox.
tinea.
Symptoms of protozoan and helminthic diseases are due to tissue damage due to growth of the parasite on the tissues. waste products excreted by the parasite. products released from damaged tissues. tissue damage due to growth of the parasite on the tissues and waste products excreted by the parasite. tissue damage due to growth of the parasite on the tissues, waste products excreted by the parasite, and products released from damaged tissues.
tissue damage due to growth of the parasite on the tissues, waste products excreted by the parasite, and products released from damaged tissues.
Western blotting is best used for which of the following? to detect very low amounts of nonprecipitating antibody in a sample to detect RNA fragments with specific nucleotide sequences to detect a specific protein in a mixture to detect DNA fragments with specific nucleotide sequences
to detect a specific protein in a mixture
What is the purpose of conjugated vaccines? to provide enhanced immune response by mimicking a real infection to provide protection against toxins to provide protection against viruses to enhance the immune response of children to polysaccharide antigens
to enhance the immune response of children to polysaccharide antigens
In which of the following cases would the Limulus amebocyte lysate (LAL) assay be used? to ensure that a sterilized medical device is free of endotoxin to check for enterotoxins to detect the presence of the botulinum toxin to confirm the diagnosis of gas gangrene
to ensure that a sterilized medical device is free of endotoxin
Assume you have isolated an unknown virus. This virus has a single, positive sense strand of RNA, and possesses an envelope. To which group does it most likely belong? papovavirus togavirus herpesvirus retrovirus picornavirus
togavirus
Which of the following is NOT a cytopathic effect of viruses? inclusion bodies forming in the cytoplasm or nucleus increased cell growth cell death toxin production host cells fusing to form multinucleated syncytia
toxin production
All of the following contribute to a pathogens invasiveness EXCEPT cell wall components. hyaluronidase. coagulases. toxins. capsules.
toxins
When microbial control methods are used, microbes are destroyed at a constant rate; there is no instantaneous death of all the microbes present. That microbial death rate is influenced by all of the following factors EXCEPT __________. the time of exposure toxins produced by the microbe the microbial characteristics the number of microbes
toxins produced by the microbe
To vaccinate children against the bacterial infection diphtheria, pure diphtheria toxin is chemically modified and injected as a vaccine. This is an example of which type of vaccine? attenuated whole agent vaccine inactivated whole agent vaccine toxoid vaccine subunit vaccine
toxoid vaccine
Biotechnology involves the use of microorganisms to make desired products. use of animal cells to make vaccines. development of disease-resistant crop plants. use of microorganisms to make desired products and the use of animal cells to make vaccines. use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistanct crop plants.
use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistanct crop plants.
Which of the following are sources of antibodies for serological testing? vaccinated animals monoclonal antibodies viral cultures vaccinated animals and monoclonal antibodies vaccinated animals, monoclonal antibodies, and viral cultures
vaccinated animals and monoclonal antibodies
The rise in herd immunity amongst a population can directly attributed to increased use of antibiotics. antibiotic-resistant microorganisms. improved handwashing. None of the answers is correct. vaccinations.
vaccinations.
All of the following are reasons why an HIV vaccination has not been developed EXCEPT there is no known organism that can provide a model of natural immunity. small and inexpensive animals for vaccine research are not available. HIV has a high mutation rate so one vaccination would not be effective to treat the world-wide pandemic. use of a weakened virus would potentially transmit the infection. vaccines are not effective against viral infections.
vaccines are not effective against viral infections.
All of the following occur during inflammation. What is the first step? margination diapedesis phagocyte migration vasodilation repair
vasodilation
Plague is transmitted through the bite of an infected flea. Which of the following best describes this mode of transmission? vehicle transmission direct contact transmission indirect contact transmission vector transmission
vector transmission
Self-replicating DNA used to transmit a gene from one organism to another is a vector. clone. PCR. library. Southern blot.
vector.
During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years. The method of transmission of the disease in the situation was vector-borne. direct contact. vehicle. droplet. indirect contact.
vehicle
A dog develops a diarrheal disease after drinking water from a creek during a hike with his owner. Which of the following best describes this method of disease transmission? contact transmission vehicle transmission vector transmission There is not enough information to determine the mode of transmission.
vehicle transmission
The clumping of test cells indicates a negative test result in the complement-fixation test. viral hemagglutination inhibition test. direct agglutination test. precipitation test. indirect agglutination test.
viral hemagglutination inhibition test.
Cytopathic effects are changes in host cells due to protozoan infections. helminthic infections. fungal infections. viral infections. bacterial infections.
viral infections.
Certain traits that allow pathogens to create infection and cause disease are termed virulence factors. collagenases. streptokinases. hyaluronidases.
virulence factors.
Which of the following is an organic growth factor? peptone H2O glucose NH4H2PO4 vitamin B1
vitamin B1
Drug resistance occurs when antibiotics are used indiscriminately. against antibiotics and not against synthetic chemotherapeutic agents. when antibiotics are taken after the symptoms disappear. because bacteria are normal microbiota. All of the answers are correct.
when antibiotics are used indiscriminately.
Epidemiology is defined as the study of when a disease occurs. where a disease occurs. where and when a disease occurs, and how it is transmitted. how a disease is transmitted.
where and when a disease occurs, and how it is transmitted.
Which of the following types of transplant is least compatible? xenotransplant isograft autograft allograft All of these types of tranplant are equally compatible.
xenotransplant
During a flood, a community's well water system is contaminated with a pathogenic fungus. If the residents boil their water for 15 minutes prior to consumption, will they be protected? probably not definitely not yes, most likely
yes, most likely
