Micro Final (quiz questions)
The genome of which of the following types of animal virus can act directly as mRNA? dsRNA viruses +ssRNA viruses -ssRNA viruses retroviruses ssDNA viruses
+ssRNA viruses
Which of the following is known to be teratogenic? cytomegalovirus Epstein-Barr virus Borrelia Plasmodium dengue virus
cytomegalovirus
What are NOD proteins? receptors of microbial molecules in phagocyte cell membranes activators of complement cytoplasmic receptors of microbial molecules cellular signals triggering inflammation chemotactic factors
cytoplasmic receptors of microbial molecules
Which of the following are examples of pyrimidines? cytosine and guanine uracil and adenine thymine and guanine cytosine and thymine thymine and adenine
cytosine and thymine
What is the underlying problem in most acquired immunodeficiencies? declining cell-mediated immunity declining humoral immunity eosinophilia anemia production of autoantibodies
declining cell-mediated immunity
In Gram staining, ethanol-acetone is used as a drying agent. decolorizing agent. counterstain. primary stain. mordant.
decolorizing agent.
The function of a mordant in staining procedures is to provide contrasting color. remove dye from certain structures. decrease the solubility of dye molecules. damage cellular structures so they take up dyes better. fix the specimen to the slide.
decrease the solubility of dye molecules.
Nucleic acid polymers, proteins, and complex carbohydrates are all produced by hydrogen bonding. dehydration synthesis. catabolic reactions. hydrolytic reactions. exchange reactions.
dehydration synthesis.
Exogenous antigens are processed for immune recognition by ________ cells. dendritic helper T all nucleated macrophage dendritic and macrophage
dendritic and macrophage
"Ringworm" is caused by parasitic worms that infect the skin. dermatophytes that have invaded deep layers of the skin. a hypersensitivity reaction caused by superficial contact with dermatophytes. immunosuppression due to HIV infection. dermatophytes growing in the upper dead tissue layers of the skin.
dermatophytes growing in the upper dead tissue layers of the skin.
Blood agar plates are an example of ________ medium. defined reducing selective differential transport
differential
Lipid-soluble molecules would be expected to cross the cytoplasmic membrane by which of the following processes? osmosis active transport group translocation facilitated diffusion diffusion
diffusion
Which of the following is a characteristic shared by DNA and RNA polymerases? efficiency of proofreading direction of polymerization type of nucleotides used speed dependence on helicase
direction of polymerization
Semiconservative DNA replication means that nucleotides are constantly being recycled as cells make DNA. each strand of a double-stranded DNA molecule is replicated differently. the sequence of a DNA molecule is preserved as it is being replicated. the cell can proofread its newly synthesized DNA only part of the time. each daughter DNA molecule is composed of one original strand and one new strand.
each daughter DNA molecule is composed of one original strand and one new strand.
What is the mode of transmission of Diphyllobothrium latum? eating raw fish eating under cooked beef Mosquito bite Ingesting food with larvae.
eating raw fish
What is the mode of transmission of Taenia saginata? eating raw fish eating under cooked beef Mosquito bite Ingesting food with larvae.
eating under cooked beef
Which of the following causes of viral meningitis is transmitted by the fecal-oral route? West Nile virus California encephalitis virus rabies echovirus Eastern equine encephalitis virus
echovirus
Which of the following causes of viral meningitis is transmitted by the fecal-oral route? rabies Eastern equine encephalitis virus California encephalitis virus echovirus West Nile virus
echovirus
Exposure to large accumulations of bird dropping may result in which of the following mycoses? histoplasmosis Pneumocystis pneumonia blastomycosis valley fever coccidioidomycosis
histoplasmosis
Which of the following is an active enzyme? subtrate cofactor coenzyme holoenzyme apoenzyme
holoenzyme
Which of the following is a CORRECT pairing of metabolic terms? dehydration: decomposition synthesis: exothermic synthesis: catabolism hydrolysis: decomposition catabolism: endothermic
hydrolysis: decomposition
A microorganism found living under conditions of high ________ is a barophile. salt concentrations pH values hydrostatic pressure carbon dioxide levels oxygen concentrations
hydrostatic pressure
A cell placed in a(n) __________ solution will __________ water. isotonic; lose hypotonic; gain isotonic; gain hypotonic; lose hypertonic; gain
hypotonic; gain
The integration of phage DNA into the bacterial chromosome occurs because of identical DNA sequences in both the phage's ability to synthesize enzymes to enter the bacterium similar RNA nucleotides in both the similarity in enzyme metabolism
identical DNA sequences in both
Prokaryotic operons typically include a(n) ________ and a(n) ________ with multiple genes. inducer; repressor operator; promoter promoter; repressor operator; terminator CAP-binding site; inducer
operator; promoter
All of the following are possible consequences of pelvic inflammatory disease EXCEPT: ectopic pregnancy. miscarriage. sterility. orchitis.
orchitis.
The use of salt and sugar in preserving various types of foods is an application of which of the following concepts? pH nitrogen fixation hydrostatic pressure osmotic pressure quorum sensing
osmotic pressure
Microaerophiles are microbes that grow best at low salt concentrations. hydrostatic pressure. pH values. carbon dioxide levels. oxygen levels.
oxygen levels.
Common skin warts are the result of infection with herpesviruses. papillomaviruses. poxviruses. parvoviruses. rubeola virus.
papillomaviruses.
The least common type of polio is nonparalytic polio. minor polio. an asymptomatic infection. postpolio syndrome. paralytic polio.
paralytic polio.
Which of the following is the major sign or symptom of mumps? deafness parotitis difficulty in breathing diarrhea nausea and vomiting
parotitis
Bacterial cell walls are composed of waxes. carbohydrates and waxes. peptides and polysaccharides. polysaccharides. peptides.
peptides and polysaccharides.
What is the primary symptom of Enterobius infections? bloody diarrhea liver enlargement perianal itching intestinal blockage
perianal itching
All of the following structures are associated with eukaryotic cells EXCEPT: cytoskeleton. cilia. periplasmic space. flagella. glycocalyx.
periplasmic space.
Which of the following terms is NOT associated with bacterial cell walls? tetrapeptide lipoteichoic acids peritrichous porins peptidoglycan
peritrichous
Flagella that cover the surface of a prokaryotic cell are called peritrichous. spirochetes. polar. biofilms. filamentous.
peritrichous.
A macromolecule containing two fatty acids and a phosphate group is a phospholipid. wax. saturated fatty acid. steroid. glycerol.
phospholipid.
Lipids found in the membranes of most eukaryotic cells are triglycerides. waxes. steroids. polyunsaturated fats. phospholipids.
phospholipids.
A cell that uses an organic carbon source and obtains energy from light would be called a lithoautotroph. chemoautotroph. photoheterotroph. photoautotroph. chemoheterotroph.
photoheterotroph
Which of the following is paired incorrectly? algae: glycocalyx absent archea: polysaccharide cell wall fungi: cellulose, chitin, and/or glucomannan cell wall plants: cellulose and carrageenan cell wall bacteria: peptidoglycan cell wall
plants: cellulose and carrageenan cell wall
DNA is composed of repeating units of sugars, phosphates, and nucleic acids. This is an example of a lipid. monomer. polymer. micelle. salt.
polymer.
The highly destructive form of Hansen's disease is the result of autoimmune disease triggered by Mycobacteriu leprae. poor immune response to Mycobacterium leprae. poor immune response to Streptococcus agalactiae. infection with rabies virus. intracellular infection with Clostridium botulinum.
poor immune response to Mycobacterium leprae.
Slow deterioration of muscle function occurring over many years occurs in postpolio syndrome. African sleeping sickness. West Nile encephalitis. minor polio. leprosy.
postpolio syndrome.
A limiting factor for viral infection is presence of specific receptor molecules on the host cell internal metabolic temperature of the host cell nutrition of the host cell stage of cell cycle of the host cell
presence of specific receptor molecules on the host cell
Class I MHC molecules are essential for recognition of class II MHC. detection of IL-2. presentation of exogenous antigens. recognition of chemokines. presentation of endogenous antigens.
presentation of endogenous antigens.
Carbolfuchsin is the ________ in the acid-fast stain. fixing reagent decolorizer primary stain mordant counterstain
primary stain
Class II MHC are found on red blood cells. cytoplasmic membranes of nucleated cells. the skin. muscle cells. professional antigen-presenting cells.
professional antigen-presenting cells.
A virion is composed of protein, either RNA or DNA, and possibly lipid lipid, protein, and both RNA or DNA protein and either RNA or DNA protein and both, RNA and DNA
protein, either RNA or DNA, and possibly lipid
Toxoplasmosis is caused by a virus protozoa bacteria fungus
protozoa
Which of the following is found in nucleic acids? amino groups carboxylic acid glycerol R group purines
purines
Which of the following nervous system diseases is treated with both passive and active immunization? primary amebic meningoencephalopathy botulism rabies West Nile encephalitis arboviral encephalitis
rabies
Persons with asymptomatic infections may be _____________ of disease. contaminants zoonoses reservoirs vector
reservoirs
The disease known as "Croup" is often a result of infection with which of the following? influenzavirus respiratory syncytial virus Bordetella pertussis hantavirus Mycoplasma pneumoniae
respiratory syncytial virus
Using a microscope, you observe an amoeba moving toward a food source. This is an example of responsiveness. growth. metabolism. reproduction. cellular structure.
responsiveness.
Reverse transcriptase is associated with which of the following? dsRNA viruses -ssRNA viruses retroviruses +ssRNA viruses dsDNA viruses
retroviruses
The viruses responsible for the majority of infant deaths resulting from diarrhea in the world are the hepaciviruses. noroviruses. astroviruses. caliciviruses. rotaviruses.
rotaviruses.
Which of the following can cause birth defects? rubella chickenpox measles smallpox roseola
rubella
All of the following are types of light microscopes EXCEPT phase-contrast. scanning tunneling. fluorescent. confocal. bright-field.
scanning tunneling.
"Swimmer's itch" is an initial symptom of which of the following? tularemia Lyme disease schistosomiasis Chagas' disease malaria
schistosomiasis
Merozoites are a result of conjugation. schizogony. meiosis. crossing over. mitosis.
schizogony.
Which of the following methods provides information about the number of living cells in a sample of bacterial culture? a Coulter counter flow cytometry a Petroff-Hauser counting chamber membrane filtration serial dilution and viable plate count
serial dilution and viable plate count
Which of the following is an iron-binding protein produced by pathogens to access the body's store of iron? ferritin transferrin siderophores gastroferritin hemolysin
siderophores
What is the role of interleukins? chemotaxis of leukocytes complement activation ensuring production of enough leukocytes signaling between leukocytes production of virally infected cells
signaling between leukocytes
If the codon AAA is changed to AAG, it still codes for the amino acid lysine; this is an example of a dimer formation. silent mutation. missense mutation. frameshift mutation. nonsense mutation.
silent mutation.
The protein projections on the surface of a virus that are involved in attachment to the host cell are called spikes hooks pili cilia
spikes
The molecule that an enzyme acts upon is known as its coenzyme. substrate. apoenzyme. catalyst. product.
substrate.
Amino acids are delivered in their appropriate order by tRNAs. rRNAs. RNA-induced silencing complexes (RISC). ribozymes. mRNAs.
tRNAs.
Intermediate hosts become infested with tapeworms through ingestion of gravid proglottids. mature tapeworms. cysticerci. tapeworm larvae. tapeworm eggs.
tapeworm eggs.
Which of the following is another term for a lysogenic phage? retrovirus temperate phage nucleocapsid enveloped virus bacteriophage
temperate phage
AIDS has gotten much less public attention and media coverage today than it did from the 1980s through the 1990s. Many public health officials fear that this decrease in publicity could lead to the following consequence. A decrease in AIDS funding. Self-satisfaction about the spread of HIV. People becoming less aware of the severity of HIV Less advocacy for AIDS education programs All of the above
All of the above
Untreated gonorrhea in males and females may lead to sterility. urinary tract infection. pelvic inflammatory disease All of the above
All of the above
Which of the following is AIDS defining condition? Repeated candidiasis tuberculosis Repeated Herpes virus infection Histoplasmosis All of the above
All of the above
All of the following are diseases known to be caused by prions EXCEPT: Creutzfeldt-Jakob disease. Alzheimer's disease. scrapie. kuru. bovine spongiform encephalopathy.
Alzheimer's disease.
HIV diagnosis often relies on the detection of HIV____________ in the blood. Particles Antibodies Proteins reverse transcriptase
Antibodies
Which of the following statements about T lymphocytes is FALSE? T lymphocytes are called such because they mature in the thymus. T lymphocytes directly attack cells and produce the cell-mediated immune response. T lymphocytes produce antibody molecules. There are three types of T lymphocytes. T lymphocytes have TCRs that recognize antigen only if it is bound to MHC.
T lymphocytes produce antibody molecules.
Which of the following arthropods does NOT transmit diseases by sucking blood from a human host? Mosquitoes Kissing bug House flies Fleas
House flies
Which of the following immunoglobulins is produced by plasma cells in response to an allergen? IgM IgD IgA IgE IgG
IgE
The most prevalent antibody class in the blood is IgA. IgM. IgE. IgD. IgG.
IgG.
Where is DNA stored?
In the sequence
All of the following are AIDS- defining conditions EXCEPT: Influenza Pneumocystis jiroveci invasive cancer of the uterine cervix Kaposi's sarcoma
Influenza
What is the mode of transmission of Ascaris lumbricoides? Larvae penetrate skin. Ingestion of cyst or eggs in the contaminated food and water. Mosquito bite Eating raw fish
Ingestion of cyst or eggs in the contaminated food and water.
All of the following are true statements concerning Toxoplasma infection EXCEPT: It is typically contracted by eating undercooked meat. The majority of infected people are asymptomatic. In healthy individuals, the infection is self-limiting and results in no permanent damage. It causes severe problems when it infects a fetus. It is a rare infection.
It is a rare infection.
Which of the following is TRUE of foodborne botulism? Normal food preparation methods can prevent it. It is not a life-threatening infection even when left untreated. It is an intoxication disorder. An effective vaccine is available. Large amounts of bacteria must be consumed to produce disease.
It is an intoxication disorder
Which of the following is NOT a function of the eukaryotic cytoskeleton? It strengthens the cell surface. It anchors organelles within the cell. It plays a role in cytoplasmic streaming. It makes amoeboid action possible. It helps organelles move within the cytosol.
It strengthens the cell surface.
Which of the following bacterial genera protects areas of the body such as the intestinal tract and the vagina from invasion by pathogens? Mycobacterium Staphylococcus Listeria Lactobacillus Corynebacterium
Lactobacillus
Each of the following parasites is transmitted by mosquito EXCEPT: Leishmania donovani Wuchereria bancrofti Plasmodium vivax Plasmodium falciparum
Leishmania donovani
Contaminated food is the source of ________, which causes meningitis in the elderly and susceptible persons. Streptococcus pneumoniae Streptococcus agalactiae Listeria monocytogenes Haemophilus influenzae Neisseria meningitidis
Listeria monocytogenes
Which of the following causative agents of bacterial meningitis is transmitted by contaminated food? Haemophilus influenzae Listeria monocytogenes Neisseria meningitidis Streptococcus pneumoniae
Listeria monocytogenes
Bacteria that have an axial filament cause which of the following diseases? Lyme disease gonorrhea syphilis Both A and B are correct. Both A and C are correct.
Lyme disease
Which of the following statements concerning cellular metabolism is FALSE? The goal of metabolism is reproduction of the organism. ATP is used in the formation of macromolecules. Macromolecules are converted into cell structures via catabolism. Enzymes are used in both catabolic and anabolic reactions. Energy obtained from nutrients or light is stored in the bonds of ATP.
Macromolecules are converted into cell structures via catabolism.
Schizogony is an important aspect of which of the following diseases? Chagas' disease toxoplasmosis malaria plague schistosomiasis
Malaria
Why are modern light microscopes better than the ones Leeuwenhoek used? Modern microscopes are compound instead of simple. Modern microscopes have a fivefold better resolution. Modern lenses are made of prisms. Modern microscopes are compound and have fivefold better resolution. Modern microscopes have lenses with smaller numerical apertures.
Modern microscopes are compound and have fivefold better resolution.
Which of the following does NOT transmit HIV? Homosexual activity Heterosexual activity Mosquitoes Human milk
Mosquitoes
A type of lymphocyte called a(n) ________ detects cells with abnormal surface proteins and kills them. mast cell NK cell eosinophil neutrophil basophil
NK cell
Ophthalmia neonatorum is an infection caused by Neisseria gonorrhoeae. Gardnerella vaginalis. Treponema pallidum. Staphylococcus aureus.
Neisseria gonorrhoeae.
Which of the following is mismatched? Staphylococcus aureus- toxic shock syndrome Clostridium perfringens- gas gangrene Neisseria meningitidis- scarlet fever Clostridium difficile - pseudomembranous colitis
Neisseria meningitidis- scarlet fever
The only type of bacterial meningitis that becomes epidemic is caused by Haemophilus influenzae. Neisseria meningitidis. Streptococcus agalactiae. Listeria monocytogenes. Streptococcus pneumoniae.
Neisseria meningitidis.
Which of the following are considered roundworms? Flukes Tapeworms Nematodes All of the above are correct
Nematodes
Infection with which of the following species of Plasmodium is usually fatal? P. malariae P. falciparum P. vivax P. ovale All of these can cause a fatal infection.
P. falciparum
Cycles of fever, chills, anemia and headache along with passage of dark colored urine are the symptoms of infection with yellow fever virus. dengue virus. P. vivax. P. ovale. P. falciparum.
P. falciparum.
Microbial molecules detected by phagocytes are called NODs. prostaglandins. TLRs. leukotrienes. PAMPs.
PAMPs.
Pathogens are examples of what type of symbiotic relationship? Mutualism Commensalism Parasitism Pathogens can come from all three symbiotic associations.
Parasitism
All of the following statements concerning pili are true EXCEPT: Pili facilitate the transfer of DNA among bacterial cells. Pili are longer than fimbriae and flagella. A bacterial cell will usually have only one or two pili. Pili are composed of protein called pilin. Not all bacteria have pili.
Pili are longer than fimbriae and flagella.
Schizogony is an important aspect of which of the following pathogens? Plasmodium species Yersinia pestis Schistosoma mansoni Trypanosoma cruzi Toxoplasma gondii
Plasmodium species
Which of the following diseases is almost diagnostic for AIDS? Hantavirus pulmonary syndrome Pneumocystis pneumonia coccidioidomycosis blastomycosis histoplasmosis
Pneumocystis pneumonia
Which of the following diseases is almost diagnostic for AIDS? blastomycosis coccidioidomycosis Pneumocystis pneumonia histoplasmosis Hantavirus pulmonary syndrome
Pneumocystis pneumonia
Opportunistic infections typical of AIDS but rare otherwise include Pneumocystis pneumonia and Kaposi's sarcoma Tuberculosis and Shingles Folliculitis and Pneumonia Wound infection and skin infections
Pneumocystis pneumonia and Kaposi's sarcoma
All of the following statements concerning prokaryotic flagella are true EXCEPT: Treponema is an example of a bacterium that has an endoflagellum. Prokaryotic flagella are anchored to the cell wall by means of the basal body. Prokaryotic flagella can rotate 360 degrees. A "run" results from counterclockwise movement of the flagellum. Prokaryotic flagella are composed of tubulin.
Prokaryotic flagella are composed of tubulin.
Which of the following helps convert HIV into its final, virulent form? Integrase Protease reverse transcriptase gp41 gp120
Protease
What is the mode of transmission of American trypanosomiasis? Female anopheles mosquito bite Reduviidae bug bite Testse fly bite Bed bug bite
Reduviidae bug bite
Which of the following could result in hemolytic disease of the newborn? Rh-negative mother and Rh-negative father either Rh-positive mother and Rh-negative father or Rh-negative mother and Rh-positive father Rh-positive mother and Rh-positive father Rh-negative mother and Rh-positive father Rh-positive mother and Rh-negative father
Rh-negative mother and Rh-positive father
All of the following statements concerning the endoplasmic reticulum (ER) are correct EXCEPT: Rough ER contains ribosomes. The ER is continuous with the outer membrane of the nuclear envelope. Rough ER is involved in the synthesis of proteins and lipids. The ER is a system of hollow tubules. The ER functions primarily as a transport system within the cytoplasm of eukaryotic cells.
Rough ER is involved in the synthesis of proteins and lipids.
Which of the following DNA repair processes is most likely to introduce mutations into the repaired DNA? light repair base-excision repair SOS response repair single-strand repair mismatch repair
SOS response repair
You advise your pregnant friend to give her cat away because She could contract plague. She could give the cat tularemia. She could get toxoplasmosis. All of the above
She could get toxoplasmosis.
All of the following are true statements concerning tetanus EXCEPT: Soil is the reservoir. Sign and symptoms of the disease is because of the bacteria in the body. Death can result from respiratory failure. It is synonymous with lockjaw. It is transmitted via endospores.
Sign and symptoms of the disease is because of the bacteria in the body.
A series of nodular lesions on an arm that fill with pus and ulcerate through the skin is characteristic of infection with the fungus Trichophyton. Sporothrix schenckii. Epidermophyton. Micrococcus. Microsporum.
Sporothrix schenckii.
All of the following can cause urinary tract infections EXCEPT: Staphylococcus saprophyticus Staphylococcus aureus. Proteus. E. coli.
Staphylococcus aureus.
Which of the following is a frequent cause of meningitis in newborns? Streptococcus pneumoniae Haemophilus influenzae Streptococcus agalactiae Neisseria meningitidis
Streptococcus agalactiae
Erysipelas is caused by Streptococcus pyogenes. Pseudomonas aeruginosa. Bartonella henselae. Staphylococcus epidermidis. Staphylococcus aureus.
Streptococcus pyogenes.
AIDS is actually a group of signs, symptoms, and diseases associated with a common pathology, otherwise known as a(n) __________. Disease Infection Contagion Syndrome
Syndrome
The responses observed in type IV hypersensitivities result from the action of IgG and complement. T cells and phagocytes. autoantibodies. inflammatory chemicals. IgE antibodies and mast cells.
T cells and phagocytes
Cell-mediated immunity is a function of macrophages. dendritic cells. B lymphocytes. T lymphocytes. NK cells.
T lymphocytes
________ are complex communities of various types of microbes that adhere to surfaces. Isolates Biofilms Colonies Aggregates Media
Biofilms
Which of the following agents is capable of inducing conversion of a prophage back to a lytic phage? X rays UV light presence of +ssRNA Both A and B are correct. A, B, and C are correct.
Both A and B are correct. X rays, and UV light
The outermost layer of a virion fulfills which of the following functions of the virus? protection recognition replication Both A and B are correct. A, B, and C are correct.
Both A and B are correct. protection, and recognition
Impetigo can be caused by Staphylococcus aureus. Staphylococcus epidermidis. Streptococcus pyogenes. Both A and C are correct. Both B and C are correct.
Both A and C are correct. Staphylococcus aureus, and Streptococcus pyogenes
Which of the following bacterial cell structures plays an important role in the creation of biofilms? fimbriae flagella glycocalyces Both A and C are correct. A, B, and C are correct.
Both A and C are correct. fimbriae, glycocalyces
Cells of the genus Mycoplasma lack which of the following? peptidoglycan a cell membrane a cell wall Both A and C are correct. A, B, and C are correct.
Both A and C are correct.a peptidoglycan, and a cell wall
Which of the following processes requires a carrier protein? diffusion facilitated diffusion active transport Both B and C are correct. A, B, and C are correct.
Both B and C are correct. facilitated diffusion, and active transport
Which of the following forms of leishmaniasis is NOT fatal? visceral cutaneous mucocutaneous Both A and B are correct. Both B and C are correct.
Both B and C are correct. cutaneous, and mucocutaneous
Each of the following statements concerning fungi and protozoa is correct EXCEPT: Both fungi and protozoa are eukaryotic organisms Fungi possess a cell wall, whereas protozoa do not Both fungi and protozoa use flagella as their organ of motility Both fungi and protozoa generate energy in mitochondria
Both fungi and protozoa use flagella as their organ of motility
A child has a history of recurring serious bacterial infections. A blood sample shows lymphocyte levels are a little below normal, and no antibodies to the pathogens are detected in serologic tests. Based on this information, which of the following is the likeliest diagnosis for this child? systemic lupus erythematosus (SLE) hemolytic disease of the newborn Bruton-type agammaglobulinemia Grave's disease severe combined immune deficiency (SCID)
Bruton-type agammaglobulinemia
How do physicians prevent pneumocystis pneumonia in AIDS patients? By administering a medication such as penicillin when the CD4+ lymphocyte count drops to 200 cells per microliter By administering a medication such as acyclovir when the CD4+ lymphocyte count drops to 200 cells per microliter. By administering a medication such as trimethoprim-sulfamethoxazole when the CD4+ lymphocyte count drops to 200 cells per microliter. All of the above drug treatments can be given.
By administering a medication such as trimethoprim-sulfamethoxazole when the CD4+ lymphocyte count drops to 200 cells per microliter.
Each of the following statements concerning Trypanosoma cruzi is correct EXCEPT: T. cruzi is transmitted by the reduviid bug T. cruzi typically affects heart muscle, leading to cardiac failure T. cruzi occurs primarily in tropical Africa T. cruzi can be diagnosed by seeing trypomastigotes in a blood smear
T. cruzi occurs primarily in tropical Africa
Which of the following is NOT a characteristic of Okazaki fragments? They make up the lagging strand of replicated DNA. They begin with an RNA primer. They are joined together by DNA ligase. They are longer in eukaryotic cells. They are checked for accuracy by DNA polymerase III.
They are longer in eukaryotic cells.
Which of the following statements is TRUE of bacterial plasmids? They carry genes for essential metabolic functions. They are small circular DNA molecules. They are small circular DNA molecules that can replicate autonomously. They can replicate autonomously. They are always found in the nucleoid.
They are small circular DNA molecules that can replicate autonomously.
Which of the following best describes IgM antibodies? They are the antibody class found in body secretions. They interact with phagocytes and NK cells. They cause basophils and eosinophils to degranulate. They are the most common type of antibody in the blood during the initial stages of an immune response. They can cross the placenta to provide passive immunity.
They are the most common type of antibody in the blood during the initial stages of an immune response.
Which of the following statements about eosinophil function is CORRECT? They attach to the surface of parasitic helminths and produce toxins that kill the parasite. They secrete toxins onto virally infected cells. They produce defensins. They identify and spare normal cells. They are involved in the removal of neoplastic cells.
They attach to the surface of parasitic helminths and produce toxins that kill the parasite.
Which of the following statements regarding antibody function is FALSE? They can bind more than one pathogen at a time, forming complexes. They can facilitate cytotoxic attack by natural killer lymphocytes. They can prevent virus attachment to host cells. They can facilitate phagocyte attack on bacteria with a capsule (glycocalyx). They can penetrate host cells to bind intracellular antigens.
They can penetrate host cells to bind intracellular antigens.
Which of the following statements concerning allografts is TRUE? They always require complete destruction of the recipient's bone marrow cells. They are impossible to perform because the antigens between donor and recipient are so different. They induce strong type IV hypersensitivity reactions and must be treated with immunosuppressive drugs. They are the best type of transplants because they are not associated with rejection. They are the rarest type of transplants.
They induce strong type IV hypersensitivity reactions and must be treated with immunosuppressive drugs.
How are prions different from all other known infectious agents? They can be destroyed by incineration. They lack nucleic acid. They act as slow viruses. They cannot reproduce outside a cell. They cause neurological problems.
They lack nucleic acid.
Which of the following statements is TRUE of eosinophils? They decline during allergic reaction. They secrete toxins onto the surface of helminth parasites. They release prostaglandins and leukotrienes in response to microbes. They are in intact skin, sebum, tears, etc. They produce the coating of a pathogen by complement.
They secrete toxins onto the surface of helminth parasites.
provides a basis for the alternative name? Activated lymphocytes may persist for years in the body. Activated lymphocytes produce daughter cells that are identical in specificity and function. To become activated, lymphocytes require exposure to the epitope for which they are specific. Lymphocytes reactive to normal body components are removed. Lymphocytes of the adaptive immune system are highly specific for a single epitope.
To become activated, lymphocytes require exposure to the epitope for which they are specific.
Which of the following is mismatched? Toxoplasma: cilia Giardia: flagella Entamoeba: pseudopodia Plasmodium: non-motile
Toxoplasma: cilia
Which opportunistic fungal infection leads to the suspicion of HIV in patients? Pneumocystosis Toxoplasmosis Tuberculosis Cytomegalovirus
Toxoplasmosis
Which of the following is described as a sexually transmitted flagellate which produces a copious malodorous frothy, yellow green discharge with intense itching? Gardnerella vaginalis Herpes simplex II Chlamydia trachomatis Trichomonas vaginalis
Trichomonas vaginalis
A single basic dye is used in simple stains. True False
True
Accumulation of a metabolic pathway product may result in decreased activity of the pathway enzymes. True False
True
Cryptococcal meningitis can affect both healthy and immunocompromised individuals. True False
True
Cytokines are soluble regulatory proteins that act as intercellular signals and include substances such as interleukins, interferon, and growth factors. True False
True
Essential amino acids are amino acids that cannot be synthesized by an organism and so must be provided as nutrients. True False
True
Quorum sensing is involved in the development and propagation of a biofilm. True False
True
Serial dilution can be used in combination with pour plates as a method for isolating pure cultures. True False
True
Streak plates are a useful way to obtain CFUs. True False
True
Sweat can cause damage to bacteria because it contains salt and lysozyme. True False
True
The adaptive immune response requires exposure to specific epitopes for activation. True False
True
The amount of energy required for a reaction to occur is its activation energy. True False
True
Trypanosoma brucei is transmitted to animals and people by a bloodsucking fly. True False
True
Which of the following statements about transmission electron microscopy is CORRECT? Stains can be applied to create a color image. Three-dimensional images are produced. Lasers are used for visualization. Up to 1,000,000X magnification may be achieved. Living specimens may be used.
Up to 1,000,000X magnification may be achieved.
1. All of the following statements concerning viruses are true EXCEPT: Viruses enter a cell to complete the replication they have begun extracellularly. Viral capsids can assume one of three basic shapes. Tobacco mosaic virus was the first virus to be discovered and characterized. Viruses never contain both DNA and RNA. Some viruses have an outer membrane called an envelope.
Viruses enter a cell to complete the replication they have begun extracellularly.
You are examining a bacterial smear on a light microscope. You observe pinkish-red bacilli and blue cells of various shapes. You are probably looking at a smear prepared with the ________ stain. Hematoxylin and eosin Ziehl-Neelsen acid-fast Schaffer-Fulton endospore Gomori methenamine Gram
Ziehl-Neelsen acid-fast
IgE antibodies are best described as the trigger for antibody-dependent cellular toxicity (ADCC). the antibodies found in body secretions. a cause of basophil and eosinophil degranulation. the most common type of antibody in the blood during the initial phases of an immune response. those involved in complement activation.
a cause of basophil and eosinophil degranulation.
Peptidoglycan is composed of NAG, NAM, and LPS. present in all prokaryotic cells. a complex polysaccharide. Both B and C are correct. A, B, and C are correct.
a complex polysaccharide.
A reaction requires water as a reactant and produces heat. What type of reaction is likely to be involved? a synthesis reaction a decomposition reaction an exchange reaction a hydrolysis reaction The answer cannot be determined with the available information.
a decomposition reaction
Which of the following is found at the 5' end of a DNA strand? a hydrogen bond histones a phosphate group a methyl group a hydroxyl group
a phosphate group
An aquatic microbe that can grow only near the surface of the water is probably which of the following? a phototroph a lithotroph an anaerobe a heterotroph a chemotroph
a phototroph
Which of the following is NOT an example of a walled-off site of infection that contains a fluid made of dead and dying tissue cells, leukocytes, and pathogens? a boil a tumor an abscess a pimple a pustule
a tumor
Which does not refer to the shape of a virus? bacillus icosahedral (isometric) helical complex
bacillus
The modified amino acid fMet is essential for eukaryotic transcription. eukaryotic translation. bacterial transcription. bacterial translation. eukaryotic mRNA processing.
bacterial translation.
Viruses that infect bacteria are referred to as viralcidens bacteriocidins bacterialogens bacteriophages
bacteriophages
Which of the following is a type of blood cell that undergoes degranulation in type I hypersensitivity reactions? T cell macrophage basophil B cell plasma cell
basophil
Match the following: Neurotoxin which inhibits inhibitory neurons. Neurotoxin which blocks acetylcholinereceptors. Exotoxin which causes dissolution of desmosomes. Exotoxin which inhibits protein synthesis by inactivating elongation factor. A. Tetanospasmin B. Botulinum exotoxin C. Exfoliatin toxin D. Diphtheria toxin E. Anthrax toxin
A. Tetanospasmin:Neurotoxin which inhibits inhibitory neurons. B. Botulinum exotoxin:Neurotoxin which blocks acetylcholinereceptors. C. Exfoliatin toxin:Exotoxin which causes dissolution of desmosomes. D. Diphtheria toxin:Exotoxin which inhibits protein synthesis by inactivating elongation factor. E. Anthrax toxin:N/A
The normal hosts for St. Louis encephalitis virus are birds. humans. small mammals. horses. horses and humans.
birds.
The normal hosts for St. Louis encephalitis virus are humans. horses and humans. horses. birds. small mammals.
birds.
Botulism toxin disrupts motor control by killing motor neurons. blocking the release of acetylcholine by motor neurons. blocking inhibitory signals to motor neurons. blocking acetylcholine receptors on muscle cells. causing demyelination of motor neurons.
blocking the release of acetylcholine by motor neurons.
Nasal or ocular contact with water containing ________ may result in primary amebic meningoencephalitis. Naegleria Trypanosoma brucei Acanthamoeba both Acanthomoeba and Naegleria Acanthamoeba, Naegleria and Trypanosoma brucei
both Acanthomoeba and Naegleria
MacConkey agar plates represent ________ medium. a selective a differential a minimal both a differential and a selective both a minimal and a selective
both a differential and a selective
The bacterial chromosome is found in a nucleoid. found in a nucleus. usually found in the cytoplasm. both circular and found in a nucleoid. both circular and found in a nucleus.
both circular and found in a nucleoid.
Which of the following are considered to be frameshift mutations? insertions only deletions only inversions only both inversion and insertions both deletions and insertions
both deletions and insertions
Which of the following bind the constant region of IgE? monocytes mast cells eosinophils both mast cells and monocytes both eosinophils and mast cells
both eosinophils and mast cells
Which of the following substances contributes to the edema associated with inflammation? histamine defensin leukotrienes interferon both leukotrienes and histamine
both leukotrienes and histamine
Which of the following are magnifying lenses? objectives oculars prisms condensers both objectives and the oculars
both objectives and the oculars
The syndrome known as AIDS is characterized by the presence of HIV. by one or more opportunistic diseases and the presence of HIV. as an opportunistic disease resulting from herpesvirus reactivation. by cytotoxic T lymphocytes attack on CD4 T -helper cells.
by one or more opportunistic diseases and the presence of HIV.
Plasmodium falciparum produces proteins that cause ________ in addition to the anemia due to erythrocyte destruction. black vomit DIC toxemia capillary damage damage to the heart muscle
capillary damage
Which of the following processes occurs in eukaryotes but not prokaryotes? gene regulation DNA replication translation transcription capping
capping
Enzymes known as lyases participate in ________ reactions. catabolic anabolic neither anabolic nor catabolic both anabolic and catabolic oxidation-reduction
catabolic
The Gram stain works because of differences in the ________ of bacteria. cell membranes cell walls antigens genetic characteristics capsules
cell walls
Shingles, or herpes zoster, is a reactivation of the virus that causes whitlows. German measles. chickenpox. measles. smallpox.
chickenpox.
Which of the following may have served as the ultimate source of HIV? chimpanzees Apes Gorillas orangutans
chimpanzees
Short, hairlike structures used only by eukaryotic cells for movement are called cilia. flagella. pseudopodia. fimbriae. pili.
cilia.
Which of the following is characteristic of prokaryotic genomes but NOT eukaryotic genomes? circular chromosomes typically consist of a few to several chromosomes histones linear chromosomes enclosed in a nuclear membrane
circular chromosomes
Which of the following is characteristic of prokaryotic genomes but NOT eukaryotic genomes? enclosed in a nuclear membrane circular chromosomes typically consist of a few to several chromosomes histones linear chromosomes
circular chromosomes
Tetanus, botulism, and gangrene are all associated with which of the following? lactobacilli clostridia streptococci mycoplasmas actinomycetes
clostridia
Dust storms in arid regions of the Southwestern U.S. may lead to outbreaks of histoplasmosis. blastomycosis. Pneumocystis pneumonia. Hantavirus pulmonary syndrome. coccidioidomycosis.
coccidioidomycosis.
Many vitamins are important ________ of enzymes. protein cofactors allosteric inhibitors competitive inhibitors coenzymes activators
coenzymes
Sulfanilamide is an antimicrobial drug that mimics the shape of an important substrate for a particular bacterial enzyme, thereby inhibiting the enzyme. This type of inhibition is known as feedback inhibition. allosteric inhibition. allosteric activation. noncompetitive inhibition. competitive inhibition.
competitive inhibition.
Variant Creutzfeldt-Jakob disease can be prevented by avoiding contact with bird droppings. contaminated waterways. contact with mosquitoes. consumption of undercooked meat. consumption of contaminated meat.
consumption of contaminated meat.
In conjugation, F+ cells contain an F plasmid. serve as recipient cells. do not have conjugation pili. can transfer DNA only to other F+ cells. contain "jumping genes."
contain an F plasmid.
Even though mycoplasmas pass through filters that normally trap bacteria, they are known to be bacteria, not viruses, because they synthesize peptidoglycan. contain both DNA and RNA. divide by binary fission. contain both DNA and RNA and divide by binary fission. synthesize peptidoglycan and divide by snapping division.
contain both DNA and RNA and divide by binary fission.
Poliovirus is most often transmitted via droplets. household pets. contaminated water. mosquitoes. endospores.
contaminated water.
When cells are placed in a hypertonic solution, they lose water and shrivel. This process is called plasmalemma. passive transport. periplasm. crenation. endocytosis.
crenation.
All of the following are associated with the nucleus of a eukaryotic cell EXCEPT: chromatin. nucleolus. histones. nucleoplasm. cristae.
cristae.
A baby arrives at an emergency room suffering from violent muscles spasms and difficulty breathing. The baby's body is so rigid a proper exam is difficult, but the staff note the baby is only a few weeks old and the umbilicus has not healed properly. The signs are consistent with which of the following diseases? acute bacterial meningitis listeriosis tetanus infant botulism rabies
tetanus
All of the following terms can be used to refer to both a bacterial genus and an arrangement or shape of bacterial cells EXCEPT: bacillus. streptococcus. sarcina. tetrad. staphylococcus.
tetrad.
Production of secretory vesicles is a function of which of the following? chloroplasts endoplasmic reticulum the nucleus the Golgi body Centrioles
the Golgi body
Encephalitis is an infection of the meninges. the cauda equina. the brain. neurons of the peripheral nervous system. the eye.
the brain.
Opsonization is nonspecific leukocyte secretion of toxins onto the surface of virally infected cells. the coating of a pathogen by complement to facilitate phagocytosis. damage resulting in cell lysis. phagocyte receptors detecting PAMPs. the sticking of monocytes to the wall of the blood vessels at the site of infection.
the coating of a pathogen by complement to facilitate phagocytosis.
The phenomenon known as chemotaxis is defined as the coating of a pathogen by complement. the squeezing of cells through the lining of capillaries. an increase in allergies and helminth infection. the release of prostaglandins and leukotrienes in response to microbes. the movement of a cell toward or away from a chemical stimulus.
the movement of a cell toward or away from a chemical stimulus.
A few days of fever with vomiting followed by high fever, jaundice, and "black vomit" are characteristic of yellow fever. Chagas' disease. malaria. schistosomiasis. dengue fever.
yellow fever.
Epstein-Barr virus infections are typically asymptomatic in ________ because of incomplete development of adaptive immunity. adolescents AIDS patients adults the elderly young children
young children
Which of the following types of animal virus requires RNA-dependent RNA transcriptase to be replicated? +ssRNA viruses ssDNA viruses retroviruses -ssRNA viruses dsDNA viruses
-ssRNA viruses
Approximately how many people are living with HIV worldwide? 40 million 39.5 billion 25.8 million 3.5 Million
40 million
DNA is composed of four nucleotides, A, C, G and T. Each codon is composed of three nucleotides. The number of possible codons is 12. 4. 32. 16. 64.
64.
Which of the following statements regarding the cell-mediated immune response is TRUE? Cytotoxic T lymphocytes do not require antigen presentation to become activated. A single cytotoxic T lymphocyte can kill many target cells. Helper T lymphocytes have no role in the activation of cytotoxic T lymphocytes. Cytotoxic T lymphocytes interact with antibodies that have bound antigen to identify their target. Cytotoxic T lymphocytes kill by producing hydrogen peroxide.
A single cytotoxic T lymphocyte can kill many target cells.
ATP energy is expended in which of the following processes?
ACTIVE and GROUP TRANSLOCATION
Which of the following is both a codon for an amino acid and a start signal? AAA AUG UGA GAU UAG
AUG
Which of the following pairings is incorrect? Aflatoxin- controls uterine bleeding and relieves migraine. Coccidioides immitis - Valley fever Candida albicans - oral and vaginal thrush Histoplasma capsulatum- Spelunker's disease
Aflatoxin- controls uterine bleeding and relieves migraine.
Tsetse flies transmit St. Louis encephalitis. Venezuelan equine encephalitis. new variant Creutzfeldt-Jakob disease. African sleeping sickness. trachoma.
African sleeping sickness.
Which of the following is TRUE concerning the structure and function of enzymes? Competitive inhibition of an enzyme occurs when an inhibitor binds to an allosteric site on the enzyme. Enzymes can function at a wide range of pH. An apoenzyme is a combination of a cofactor bound to a holoenzyme. All enzymes bind cofactors necessary for their function. After an enzyme has catalyzed a reaction, it resumes its original shape and can interact with a new substrate molecule.
After an enzyme has catalyzed a reaction, it resumes its original shape and can interact with a new substrate molecule.
Which of the following statements concerning rabies is FALSE? All mammals can serve as a reservoir for the disease. Treatment includes vaccination. It is caused by an ssRNA virus. Bats are the source of most cases of rabies in humans. Transmission is usually via a bite from a rabid animal.
All mammals can serve as a reservoir for the disease.
Which of the following statements concerning rabies is FALSE? Transmission is usually via a bite from a rabid animal. Bats are the source of most cases of rabies in humans. It is caused by an ssRNA virus. All mammals can serve as a reservoir for the disease. Treatment includes vaccination.
All mammals can serve as a reservoir for the disease.
Which of the following statements about lymphocytes is FALSE? Once they are mature, they migrate to secondary lymphoid organs. The glycoproteins on the surface of a lymphocyte are designated with the prefix CD, for "cluster of differentiation." Lymphocytes have integral surface proteins by which they can be recognized. B and T lymphocytes can be differentiated using a bright-field light microscope. Lymphocytes have different types of CD molecules in their cytoplasmic membranes.
B and T lymphocytes can be differentiated using a bright-field light microscope.
The lymphocytes of adaptive immunity called ________ mature in the red bone marrow. T cells macrophages B cells NK cells dendritic cells
B cells
The white blood cells primarily responsible for adaptive immunity are NK lymphocytes and neutrophils. macrophages and neutrophils. neutrophils and dendritic cells. macrophages and eosinophils. B lymphocytes and T lymphocytes.
B lymphocytes and T lymphocytes.
Which of the following is mismatched? C. botulinum- upper respiratory tract S. aureus- nose and skin Clostridium perfringens- soil B. anthracis- contact with infected animal or inhalation of endospores
C. botulinum- upper respiratory tract
Which of the following acts as a chemotactic factor? factor P interferon β leukotriene C5a MAC
C5a
Which of the following is mismatched? TM- entry of the virus CCR5- Encodes for MA, CA and NC SU- attachment MA- maintain viral structure, transport viral genome to host cell nucleus and viral assembly
CCR5- Encodes for MA, CA and NC
All of the following are HIV antigens EXCEPT: TM CD4 RT MA
CD4
Symptoms of AIDS appear when CD4 counts are under 200/µl CD4 counts are at 1000/µl CD8 counts are over 1000/µl CD8 counts are under 700/µl
CD4 counts are under 200/µl
Which of the following recognizes and binds to MHC I proteins and helps stabilize the binding of epitopes to T cell receptors? CD26 MHC I CD8 CD95 CD4
CD8
All of the following statements concerning centrioles are true EXCEPT:
CENTRIOLES ARE FOUND IN ALL ORGANISMS EXCEPT PROKARYOTES.
Pure cultures are often obtained by isolating inoculums. broths. specimens. streaks. CFUs (colony forming units).
CFUs (colony forming units).
How is the development of autoimmunity normally prevented? Clonal deletion of T cells and regulatory T cell suppression prevent autoreactive T cell activation. T lymphocytes require a specific set of cytokine signals to become activated. Regulatory T cells suppress autoimmune responses. Clonal deletion of T cells, lack of necessary cytokine signals, and regulatory T cell suppression prevent activation of autoreactive T cells. T lymphocytes that respond to autoantigens in the thymus undergo clonal deletion.
Clonal deletion of T cells, lack of necessary cytokine signals, and regulatory T cell suppression prevent activation of autoreactive T cells.
The events of ________ are initiated at sequences called origins. translation transposition DNA replication splicing transcription
DNA replication
The process of ________ requires the activity of DNA ligase. transduction transcription translation DNA replication capping
DNA replication
Failure of thymus development may result in type I diabetes. Grave's disease. Bruton-type agammaglobulinemia. chronic granulomatous disease. DiGeorge syndrome.
DiGeorge syndrome.
Which of the following statements concerning the Rh factor is CORRECT? Eighty-five percent of humans are Rh positive. Eighty-five percent of the human population is Rh negative. The Rh antigen is on white blood cells. Preexisting antibodies occur in 85% of the population. Rh antibodies are more abundant than the ABO antibodies.
Eighty-five percent of humans are Rh positive.
Which of the following statements concerning endocytosis and exocytosis is correct? These processes occur in both prokaryotes and eukaryotes. Endocytosis produces a structure called a food vesicle. Endocytosis is a form of passive transport, while exocytosis is a form of active transport. Waste products and secretions are exported from the cell during endocytosis. Phagocytosis is a type of endocytosis in which liquids are brought into the cell.
Endocytosis produces a structure called a food vesicle.
Which of the following is NOT true of endospores? Sporulation results in the degradation of the vegetative cell DNA. Endospores are resistant to boiling and chemicals. Bacillus and Clostridium are genera that produce them. Endospores are a reproductive structure. Endospores are dormant.
Endospores are a reproductive structure.
Which of the following is a common childhood parasite in the United States? Taenia solium Enterobius vermicularis Entamoeba histolytica Cryptosporidium parvum
Enterobius vermicularis
Toxins that affect the lining of the gastrointestinal tract are Enterotoxin Neurotoxin Cardiotoxin Cytotoxin
Enterotoxin
Which type of HIV is most prevalent in the United States? HIV-1 HIV-2 HIV-3 HIV-4
HIV-1
All of the following are true statements concerning the endosymbiotic theory EXCEPT: Mitochondria and chloroplasts can divide independently of the cell. The cristae of mitochondria evolved from the plasma membrane of prokaryotes. Eukaryotes were formed from the union of small anaerobic cells by larger aerobic cells. The endosymbiotic theory is not universally accepted. Mitochondria and chloroplasts have their own DNA and ribosomes.
Eukaryotes were formed from the union of small anaerobic cells by larger aerobic cells.
A single B lymphocyte can recognize multiple antigenic determinants. True False
False
Acid-fast cells such as Mycobacterium lose the color of the primary stain in the presence of hydrochloric acid. True False
False
All arboviruses are members of the same virus family. True False
False
As the concentration of substrate increases, the activity of the enzyme decreases. True False
False
Denaturation of a protein is always permanent. True False
False
Pneumocystis jiroveci infects only immunocompromised patients. True False
False
Rodents are a major reservoir for rabies. True False
False
The three domains proposed by Carl Woese and George Fox are the Archaea, the Eukarya, and the Protista. True False
False
What is the mode of transmission of Plasmodium spp? Female anopheles mosquito bite Reduviidae bug bite Testse fly bite Bed bug bite
Female anopheles mosquito bite
What distinguishes influenza from the common cold? Pharyngitis Malaise Nasal congestion Cough Fever
Fever
The accumulation of glucose inside a bacterial cell via phosphorylation of the molecule is an example of
GROUP TRANSLOCATION
Care in the handling and disposal of diapers in day care centers may prevent the spread of which of the following? Giardia intestinalis hepatitis A virus norovirus Salmonella enterica Cryptosporidium parvum
Giardia intestinalis
Which of the following causes "beaver fever"? Taenia saginata Giardia lamblia Campylobacter jejuni Enterobius vermicularis
Giardia lamblia
If a microbiology lab student left the safranin out of the Gram stain procedure, what would be the result? Gram-positive cells would be purple and Gram-negative cells would be colorless. Gram-positive cells would be colorless and Gram-negative cells would be pink. Gram-positive cells would be pink and Gram-negative cells would be purple. All cells would be pink. All cells would be purple.
Gram-positive cells would be purple and Gram-negative cells would be colorless.
Antibody binding to receptors on the thyroid may result in DiGeorge syndrome. autoimmune hemolytic anemia. Graves' disease. multiple sclerosis. type I diabetes.
Graves' disease.
Which of the following contributes to protecting the eyes from microbial invasion? Tears mechanically flush particles from the eyes. A mucus layer traps and removes microbes. Tears contain lysozyme and salt. Tears contain lysozyme and salt and mechanically flush particles from the eyes. Tears and mucus combine to trap microbes and remove them.
Tears contain lysozyme and salt and mechanically flush particles from the eyes.
An accident victim receives a blood transfusion. Shortly thereafter, he begins to have difficulty breathing, develops a fever, and experiences nausea and vomiting. Which of the following is the most likely interpretation of these events? The blood transfusion was mismatched and the recipient had previously been exposed to the foreign blood group antigens. The blood transfusion contained pyrogens. The blood transfusion was mismatched and contained pyrogens. The recipient had previously been exposed to foreign blood group antigens. The blood transfusion was mismatched.
The blood transfusion was mismatched and the recipient had previously been exposed to the foreign blood group antigens.
Which of the following statements concerning the chemical structure of an antibody is FALSE? Antibodies have two long peptide chains known as heavy chains. The heavy and light chains are connected by hydrogen bonds. The stem and arm are connected by a hinge. Antibodies have two short peptide chains known as light chains. Antibodies are formed of four polypeptide chains.
The heavy and light chains are connected by hydrogen bonds.
Which of the following statements concerning the chemical structure of an antibody is FALSE? The heavy and light chains are connected by hydrogen bonds. Antibodies have two short peptide chains known as light chains. The stem and arm are connected by a hinge. Antibodies have two long peptide chains known as heavy chains. Antibodies are formed of four polypeptide chains.
The heavy and light chains are connected by hydrogen bonds.
Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense against microbial invaders? The mucus is a physical trap that contains a variety of antimicrobial chemicals. The mucus contains a variety of antimicrobial chemicals and molecules. Both the mucus and the outer layer of cells are shed frequently. The mucus secreted by the mucous membrane physically traps microbes. The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.
The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.
Each of the following statements concerning malaria is correct EXCEPT: The female Anopheles mosquito is the vector. There are four species in genus Plasmodium. Release of merozoites from red blood cells causes periodic fever and chills. The principal site of gametocyte formation is the human gastrointestinal tract.
The principal site of gametocyte formation is the human gastrointestinal tract.
Which of the following is TRUE of both DNA and RNA? The purines and pyrimidines form hydrogen-bonded pairs. They contain adenine, cytosine, guanine and thymine. The "backbone" is composed of riboses and phosphates. They are usually double-stranded helices. They are highly hydrophobic macromolecules.
The purines and pyrimidines form hydrogen-bonded pairs.
Which of the following is a characteristic of the third line of defense that makes it significantly different from the second line? The response is specific to a single antigen. The response is effective on a broad range of antigens. The initial response is very rapid, beginning in minutes to a couple of hours. The responding cells are a variety of cell types. The response to a second exposure is similar to the response to a first exposure.
The response is specific to a single antigen.
Which of the following statements concerning enzymes is FALSE? They form a temporary intermediate compound with a substrate. They can be denatured if the pH of their environment is too high or too low. They always function best at 37°C. They can be used to catalyze a chemical reaction over and over again. They are usually, but not always, proteins.
They always function best at 37°C.
Which of the following is TRUE of chemokines? They are involved in B lymphocyte activation and differentiation. They ensure production of enough leukocytes. They cause basophils and eosinophils to degranulate. They are chemotactic factors for leukocytes. They are substances used to signal between leukocytes.
They are chemotactic factors for leukocytes.
Which of the following statements concerning B cell receptors (BCRs) is FALSE? They are formed in response to an encounter with an antigen. They are complementary in shape to a specific antigenic determinant that they may or may not encounter. Scientists estimate that each person forms at least 1011 different types of B lymphocytes with distinct BCRs. They are bound to the surface of B lymphocytes and have two antigen-binding sites. Each B lymphocyte is randomly generated with antibody variable regions that determine its BCR.
They are formed in response to an encounter with an antigen.
Multiple sclerosis is a type II hypersensitivity to the myelin of neurons. a genetic birth defect of the nervous system. the formation of antibodies against transplanted tissue. a type IV hypersensitivity disease in which cytotoxic T cells attack the myelin sheath of neurons. a neurological disease due to the accumulation of immune complexes in nerves.
a type IV hypersensitivity disease in which cytotoxic T cells attack the myelin sheath of neurons.
Sebum contains ________ which contributes to creating an inhospitable environment on the surface of the body. acids lysozyme salts bile collagens
acids
Treatment with glucocorticoids to suppress type IV hypersensitivity may result in autoimmune disease. primary immunodeficiency. DiGeorge syndrome. anaphylaxis. acquired immunodeficiency.
acquired immunodeficiency.
The "backbone" of the DNA molecule is composed of pentoses. amino acids. alternating phosphates and pentoses. phosphates. nitrogenous bases.
alternating phosphates and pentoses.
What functional groups are present in ALL amino acids? hydroxyl groups. amino and carboxyl groups amino and sulfhydryl groups. carboxyl groups amino groups
amino and carboxyl groups
Which of the following organisms would be most likely to contaminate a jar of pickles? an obligate anaerobe an acidophile a thermophile a neutrophile a mesophile
an acidophile
One summer, bird watchers and zookeepers in a major city notice that more birds than usual are dying. At the same time reports of human encephalitis cases increase sharply. The cerebrospinal fluid of human patients is clear. Similar enveloped RNA virus particles are detected in samples from both birds and humans. Which of the following might be responsible for this outbreak? rabies virus coxsackie A virus Cryptococcus neoformans Neisseria meningitidis an arbovirus
an arbovirus
A young woman comes into the clinic complaining of itchy, red skin and swelling on her arms and legs. She had not been in any parks or wooded areas recently, but she had been shopping. A blood sample reveals elevated levels of granulocytes. What treatment is the physician likely to prescribe at this point? antihistamines corticosteroids methylprednisolone azathioprine cyclophosphamide
antihistamines
Primary immunodeficiency diseases may be caused by malnutrition. are never associated with genetic defects. are detectable close to birth. develop later in life. are sometimes caused by severe stress.
are detectable close to birth.
Acidic dyes are lipid soluble. are used for staining negatively charged molecular structures. work best in low pH environments. are negatively charged. are negatively charged and work best at low pH.
are negatively charged and work best at low pH.
A structure that appears in a transmission electron micrograph but is NOT actually present in the specimen is known as a(n) mordant. biofilm. antigen. artifact. refraction.
artifact.
Some microbes gain access to the normally axenic central nervous system by damaging the blood-brain barrier. infecting macrophages which subsequently enter the CNS. infecting lymph nodes in the cranium. axonal transport from infected peripheral neurons. either damaging the blood-brain barrier or by axonal transport from infected peripheral neurons.
either damaging the blood-brain barrier or by axonal transport from infected peripheral neurons.
The ________ stain makes use of malachite green. endospore negative acid-fast flagellar electron microscopy
endospore
Lipid A is a(n) ______________ that stimulates the body to release chemicals that cause fever, inflammation, diarrhea, hemorrhaging, shock, and blood coagulation. exotoxin endotoxin neurotoxin cytotoxin
endotoxin
Lipid A is also known as endotoxin. lipopolysaccharide. pilin. mycolic acid. teichoic acid.
endotoxin.
A fastidious organism might be grown on which of the following types of media? reducing media transport media differential media selective media enriched media
enriched media
Most infections of the Mycobacterium avium complex are from person to person contact sexual transmission Ingestion environmental sources AND reactivation of latent infections.
environmental sources AND reactivation of latent infections.
Which of the following cells increase in number during an infection with parasitic worms? neutrophils basophils lymphocytes eosinophils macrophages
eosinophils
All of the following can be caused by Staphylococcus aureus EXCEPT: erysipelas. a carbuncle. impetigo. scalded skin syndrome.
erysipelas.
A reddening of the skin of the face that intensifies when exposed to the sun is characteristic of rubeola. chickenpox. rubella. erythema infectiosum. herpes.
erythema infectiosum.
The viral envelope closely resembles the eukaryotic cell membrane prokaryotic cell wall capsomere cytoplasm
eukaryotic cell membrane
Decomposition reactions are commonly ________ reactions. endothermic exchange exothermic anabolic dehydration
exothermic
Sour cream, yogurt and citrus fruits are easily contaminated by molds because fungi grow best in alkaline environments. these foods are anaerobic. fungi favor acidic conditions. these foods are normally kept at cold temperatures.
fungi favor acidic conditions.
Transfer of random pieces of DNA mediated by phage is known as transformation of competent cells. transposition. specialized transduction. conjugation. generalized transduction.
generalized transduction.
The ________ of a population is the time it takes for the cells to double in number. binary fission log phase exponential growth generation time arithmetic growth
generation time
When immune complexes in the blood become trapped in the kidneys the resulting disease is known as autoimmunity. anaphylaxis. glomerulonephritis. urticaria. hemolytic disease.
glomerulonephritis.
Which of the following is an example of a polysaccharide? deoxyribose glucose sucrose fructose glycogen
glycogen
Which of the following characteristics of life never occurs among viruses? metabolism growth reproduction responsiveness None of the above are possible in viruses.
growth
Tetanus vaccine contains fragments of Clostridium tetani cell walls. antibodies against Clostridium tetani endospores. inactivated tetanospasmin. inactivated Clostridium tetani endospores. antibodies against Clostridium tetani.
inactivated tetanospasmin.
Some bacteria can produce PHB, a biodegradable type of plastic. Where in these cells can this molecule be found? the nucleus endospores the cell wall inclusions the cell membrane
inclusions
All of the following are found within the mitochondrion EXCEPT: inclusions. cristae. ribosomes. DNA. two membranes.
inclusions.
Blastomycosis results from inhalation of spherules. inhalation of fungal spores. inhalation of respiratory droplets. contact with fomites. contact with infected sputum.
inhalation of fungal spores.
HIV can be spread by all of the following EXCEPT: blood products hypodermic syringes insect bites sexual intercourse
insect bites
First line of defense may be described as the coating of a pathogen by complement. the release of prostaglandins and leukotrienes in response to microbes. intact skin, mucous membranes, sebum, tears, and so forth. damage resulting in cell lysis. nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.
intact skin, mucous membranes, sebum, tears, and so forth.
Some strains of Papillomavirus are oncogenic due to their ability to escape the phagosome before lysosome fusion. integrate into the host cell DNA. lie dormant in cells for years. produce deoxyribonucleases. cause extensive damage to blood vessels.
integrate into the host cell DNA.
The immunological synapse refers to the binding of a monocyte or macrophage to antigen so that it can act as an antigen-presenting cell. interaction between a T cell and an antigen-presenting cell to produce a specialized cell-to-cell contact area. interaction between lymphocytes and foreign antigens to produce memory cells. interaction of the many cytokines produced by different immunological cells. activation of a B cell to become a plasma cell.
interaction between a T cell and an antigen-presenting cell to produce a specialized cell-to-cell contact area.
Host specificity of a virus is due to interactions between viral and cellular surface molecules. the presence or absence of a cell wall on the host cell. the presence of an envelope. particular genes that it shares with the infected cell. differences in size between the virus and the host cell.
interactions between viral and cellular surface molecules
Which of the following cytokines act as a signal between leukocytes? interleukins growth factors tumor necrosis factors interferons chemokines
interleukins
The horizontal transfer process known as transduction involves a mutagen. requires a pilus. requires a cell to be "competent." requires a plasmid. involves a virus.
involves a virus.
Which of the following is a fermentation product useful in the manufacture of cheese? pyruvic acid ethanol ammonia lactic acid acetic acid
lactic acid
When cells are metabolically active but not dividing, they are in the ________ phase. exponential stationary lag log death
lag
The growth of bacterial cultures is best described as cell division. replication. arithmetic growth. logarithmic growth. lag growth.
logarithmic growth.
Which of the following is involved in translation? mRNA only rRNA only tRNA only both mRNA and tRNA mRNA, rRNA, and tRNA are all involved.
mRNA, rRNA, and tRNA are all involved.
Enhanced immune responses to subsequent exposures to an antigen to which the body has already been exposed are known as ________ responses. primary immune third-degree immune autoimmune memory allergic
memory
The majority of cases of staphylococcal toxic shock syndrome occur in menstruating women. nasal surgery patients. anyone with an S. aureus infection. newly delivered mothers.
menstruating women.
Tumors invade other organs and tissues in a process called budding. a plaque assay. neoplasia. latency. metastasis.
metastasis.
A polypeptide in a wild type microbe contains the sequence Leu-Pro-Tyr-Ser-Pro. A phenotypic variant of the species has the peptide sequence Leu-Pro-Cys-Ser-Pro. This is an example of a(n) ________ mutation. inversion missense frameshift nonsense silent
missense
Which of the following organelles is responsible for producing most of the ATP in a eukaryotic cell? Golgi body smooth endoplasmic reticulum nucleus mitochondrion lysosome
mitochondrion
Which cell becomes a macrophage when leaving the bloodstream? monocyte basophil eosinophil neutrophil lymphocyte
monocyte
Which of the following areas of the body have mucous membranes? urinary system mouth and nasal cavity mouth nasal cavity mouth, nasal cavity, and urinary system
mouth, nasal cavity, and urinary system
Typical eukaryotic genomes are composed of ________ chromosomes. a single circular a single linear multiple linear multiple circular both linear and circular
multiple linear
Systemic lupus erythematosus (SLE or lupus) is distinct from other autoimmune disorders because it may be triggered by an infection. it is also a hypersensitivity disorder. multiple organs and tissues are affected. there is a genetic predisposition. it involves an antibody response.
multiple organs and tissues are affected.
The Ames test demonstrates that a chemical is carcinogenic in Salmonella. mutagenic in Salmonella. mutagenic in humans. carcinogenic in humans. carcinogenic.
mutagenic in Salmonella.
Which of the following chemical substances contributes to the unique characteristics of acid-fast bacteria? endotoxin mycolic acid N-acetylglucosamine peptidoglycan lipoteichoic acid
mycolic acid
Which of the following groups is noted for being pleomorphic? actinomycetes streptococci clostridia lactobacilli mycoplasmas
mycoplasmas
Viruses are generally measured in decimeters. centimeters. micrometers. nanometers. millimeters.
nanometers
Acidic dyes are commonly used for ________ stains. acid-fast flagellar endospore negative Gram
negative
In the presence of light, a particular bacterial cell experiences an increased number of tumbles and a decreased number of runs. This cell is exhibiting negative phototaxis. positive phototaxis. positive chemotaxis. negative chemotaxis. It is impossible to tell from this information.
negative phototaxis.
All of the following are associated with Neisseria meningitidis EXCEPT: transmission by inhalation of respiratory droplets. a polysaccharide capsule and fimbriae are important virulence factors. the organism typically appears as a diplococcus. no vaccines are available yet.
no vaccines are available yet.
The rules of naming organisms are called nomenclature. classification. identification. taxonomy. binomials.
nomenclature.
During the intracellular state, a virus exists solely as a protein. lipid. nucleic acid. Both B and C are correct. Both A and C are correct.
nucleic acid.
A microbe that grows only at the bottom of a tube of thioglycollate medium is probably a(n) facultative anaerobe. aerotolerant anaerobe. microaerophile. obligate anaerobe. obligate aerobe.
obligate anaerobe.
Which of the following is the best definition of "microbial antagonism"? the presence of pathogens on the surface of the skin, which will invade the body through abrasions the presence of normal microbiota that protect the body by competing with pathogens in a variety of ways to prevent pathogens from invading the body the presence of resident bacteria on the surface of the body and in cavities that connect to the surface the presence of normal microbiota that can become pathogens under certain conditions the ability of microbiota to mutate into pathogens
the presence of normal microbiota that protect the body by competing with pathogens in a variety of ways to prevent pathogens from invading the body
The perforin-granzyme pathway involves binding CD95L to infected cells, which eventually leads to cell apoptosis. presenting the foreign antigen to B cells. the production of special cell-killing proteins that act on infected or abnormal cells. the production of fever, which kills the pathogen. the production of antibodies toward the invading pathogen.
the production of special cell-killing proteins that act on infected or abnormal cells.
Which of the following phenomena produces magnification? the length of an objective lens the thickness of a microscopic specimen the refraction of radiation as it passes through a lens the numerical aperture of a lens the wavelength of a radiation source
the refraction of radiation as it passes through a lens
Which of the following is NOT included in the MALT? the spleen lymphoid tissue in the respiratory tract lymphoid tissue in the small intestine the appendix Peyer's patches
the spleen
Clonal deletion of developing T lymphocytes takes place in which location(s) in the body? the spleen the bone marrow the liver both the bone marrow and the spleen the thymus
the thymus
The antibody-binding site of an antibody is made up of the variable regions of both light and heavy chains. the light chains only. one heavy chain. the variable regions of the heavy chains. portions of both of the heavy chains only.
the variable regions of both light and heavy chains.
The Most Probable Number (MPN) method is used to determine the generation time of bacterial isolates. when samples contain obligate anaerobes. to isolate autotrophic bacteria. to estimate numbers of cells in samples with a high density of bacterial cells. to estimate numbers of cells in samples with a low density of bacterial cells.
to estimate numbers of cells in samples with a low density of bacterial cells.
Viral meningitis is also called "aseptic meningitis" to distinguish it from encephalitis. because it is vaccine-preventable. since it is treatable with antiviral medications. because it is frequently a nosocomial infection. to indicate no bacteria are involved.
to indicate no bacteria are involved.
Genetic elements known as promoters are initiation points in the process of DNA replication. transformation. transcription. mutation repair. translation.
transcription.
Genetic elements known as promoters are initiation points in the process of translation. transformation. transcription. DNA replication. mutation repair.
transcription.
RNA polymerase is primarily responsible for transformation. DNA replication. translation. polyadenylation. transcription.
transcription.
The glycocalyx of a eukaryotic cell performs all of the following functions EXCEPT: strengthening the cell surface. anchoring cells to each other. protection against dehydration. transfer of genetic material between cells. cellular recognition and communication.
transfer of genetic material between cells.
Frederick Griffith discovered the lac operon. DNA. transformation. conjugation. transposons.
transformation.
A reaction to an allergen is a ________ hypersensitivity. type V type II type III type I type IV
type I
A small amount of antigen is injected under the skin of a patient. After 30 minutes there is no apparent change at the injection site, but 36 hours later the patient reports that the area is red and swollen. This type of response is due to type III hypersensitivity. type IV hypersensitivity. immunodeficiency. type I hypersensitivity. type II hypersensitivity.
type IV hypersensitivity.
Viruses are primarily classified according to their shape. type of life cycle. size. type of nucleic acid. number of chromosomes.
type of nucleic acid.
Which of the following causes mutations by creating thymine dimers? nucleotide analogs gamma rays benzopyrene ultraviolet light nitrous acid
ultraviolet light
Which of the following would NOT normally be found as a component of a cell's nucleic acids? uracil deoxyribonucleotides thymine deoxyribonucleotides cytosine ribonucleotides adenine deoxyribonucleotides adenine ribonucleotides
uracil deoxyribonucleotides
Pleomorphic bacteria are roughly spherical. are flexible. have a slightly curved rod shape. reproduce by snapping division. vary in size and shape.
vary in size and shape.
A herpetic lesion on the finger or hand is known as a furuncle. fever blister. macule. whitlow. pox.
whitlow.