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microbiology BI280
study Unit 6-10
Question | Answer |
---|---|
Virulence is the degree of pathogenicity. True or False | True |
Pathogenicity is the ability to cause disease. True or False | True |
Which of the following virulent factors impairs phagocytosis? A. capsules B. components of the cell wall C. coagulases D. all of the above | D. all of the above |
Which of the following refers to the presence of toxins in the blood? A. bacteriemia B. anemia C. toxemia D. gonorrhoeae | C. Toxemia |
Viruses are dependent upon host cells for growth. True or False | True |
The removal of plasmids reduces virulence in which of the following organisms? A. Clostridium tetani B. Escherichia coli C. Staphylococcus aureus D. Streptococcus mutans E. Clostridium botulinum | E. Clostridium botulinum |
Which of the following is not a portal of entry for pathogens? A. mucous membranes of the respiratory tract B. mucous membranes of the gastrointetenal tract C. skin D. blood E parenteral route | D. blood |
All of the following can occur during bacterial infection. Which would prevent all of the others? A. vaccination against fimbriae B. phagocytosis C. inhibition of phogoctic digestion D. destruction of adhesins E. alteration of cytoskele | D. destruction of adhesins |
An encapsulated bacterium can be virulent because the capsule A. resists phagocytosis B. is an endotoxin C. destrous host tissues D. interferes with physiological processes | C. destrous host tissues |
A drug that binds to mannose on human cells would prevent A. the entrance of Vibrio enterotoxin B. the attachment of pathogenic E. coli C. the action of botulinum Toxin D. streptococcal pneumonia | B. the attachment of pathogenic E. coli |
The ID50 for Campylobacter sp. is 500 cells; the ID50 for Cryptosporidium sp. is 100 cells. Which of the following statements is not true? | C. Cryptosporidium is more virulent than Campylobacter |
The earliest smallpox vaccines were infected tissue rubbed into the skin of a healthy person. That recipient of the vaccine usually developed a mild case of smallpox, recovered, & was immune thereafter. The reason this vaccine did not kill more people is; | A. skin is the wrong portal of entry for smallpox B. the vaccine consisted of a mild form of the virus C. smallpox is normally transmitted by skin-to-skin contact D. smallpox is a virus E. the virus mutated Answer A |
Which of the following statements is true? A. Epstein-Barr (EB) virus binds to the host receptor fot C3 B. suface protein genes in Neisseria ganorrhoeae mutate frequently | B. suface protein genes in Neisseria ganorrhoeae mutate frequently |
Which of the following statements is true? A. evolution selects for the most virulent pathogens B. A successful pathogen doesn't kill its host before it is transmitted C. a successful pathogen never kills its host | B. A successful pathogen doesn't kill its host before it is transmitted |
Bacterial capsules form from the glycocalyx and can contribute to the virulance of the microorganism. True or False | True |
Pathology is the scientific study of disease. True or False | True |
Microorganisms that establish permanent residence without causing disease become 'normal microbiota. True or False | True |
Which type of symbiosis describes a relationship in which the symbiont benefits at the expense of the host? A. parasitism B. mutualism C. commensalism D. herocitism | A. parasitism |
S. epidermidis and S. aureus live off of dead epithelial cells on the conjunctiva of the eye. This benefits the microbes and has no effect on the host. What type of relationship is this? A. Parasitism B. mutualism C. commensalism D. herocitism | C. commensalism |
Which of the following is an emerging infectious disease? A. lyme disease B. anthrax C. mad cow disease D. hantavirus E. all of the above | E. all of the above |
Emergence of new infectious diseases is probably due to the following except? A. need of bacteria to cause disease B. humans traveling by air C. changing environments i.e. flood, drought, pollution | A. the need of bacteria to cause disease |
All members of a group of ornithologists studying barn owls in the wild have had salmonellosis (Samonella gastroenteritis). One birder is experiencing her third infection. What is the most likely source of their infections? | A. the ornithologists are eating the same food B. they are contaminating their hands while handling the owls and nests C. one of the workers is a Samonella carrier D. their drinking water is Contaminated ANSWER: b |
Which of the following statements is not true? A. E. coli never causes disease B. E. coli provides vitamin K for its host C. E. coli often exists in a mutualistic relationship with humans D. E. coli gets nutrients from intentional c | A. E. coli never causes disease |
Which of the following is NOT one of Koch's Kostulates? A. pathogen must be isolated & grown in pure culture from the diseased host B. disease must be transmitted from a diseased animal to a Healthy, susceptible laboratory animal by some form of contac | B. disease must be transmitted from a diseased animal to a Healthy, susceptible laboratory animal by some form of contact |
E. coli and humans have a mutalistic symbiotic relationship in that the E. coli make vitamin K for the human host. True or False | True |
The conjunctiva of the eye is a common portal of entry for parasitic microorganisms. True or False | True |
There are no exceptions to Koch's postulates for connecting a disease with a causative agent. True or False | False |
Clostridium tentani causes tetanus and is an example of a communicable disease. True or False | False |
A fomite is a living reservoir; e.g., ticks carry the causative agent for Lyme disease. True or False | False |
Nosocomial infections are common and occur in hospitals where there is a compromised host and a chain of infection. True or False | True |
Transcription is the synthesis of RNA from DNA. True or False | True |
RNA polymerase catalyzes transcription. True or False | True |
Genetics is the scientific study of heredity. True or False | True |
Replication is the synthesis of protein from RNA. True or False | False |
DNA is a double stranded molecule arranged in a helical shape. True or False | True |
The transfer of DNA from a donor to a recipient cell by a bacteriophage. A. conjugation B. transcription C. transduction D. transformation E. translation | C. transduction |
The transfer of DNA from a donor to a recipient as naked DNA in solution. A. conjugation B. transcription C. transduction D. transformation E. translation | D. transformation |
Feedback inhibition differs from repression because feedback inhibition A. is less precise B. is slower acting C. stops the action of Preexisting enzymes D. stops the synthesis of new enzymes E. all of the above | C. stops the action of Preexisting enzymes |
Bacteria can acquire antibiotic resistance by A. mutation B. insertion of transposons C. acquiring plasmids D. all of the above E. none of the above | D. all of the above |
Three flasks are inoculate with minimal salts broth w/E. coli. #A contains glucose. #B contains glucose and lactose. #C contains lactose. After incubation, you test the flasks for presence of Beta-galactosidase. Which flask(s)will have this enzyme | B and C |
Plasmids differ from transposons because plasmids A. become inserted into chromosomes B. are self-replicated outside the chromosome C. move from chromosome to chromosome D. carry genes for antibiotic resistance | B. are self-replicated outside the chromosome |
Eukaryotic DNA is linear while prokaryotic DNA is cirular, but both are double stranded. True or False | True |
The mechanism by which the presence of glucose inhibits the lac operon. A. catabolite repression B. DNA polymerase C. induction D. Repression E. translation | A. catabolite repression |
A mutation in microbial DNA always results in alteration of protein structure. True or False | False |
Two daughter cells are most likely to inherit which one of the following from the parent cell? A. change in a nucleotide in mRNA B. change in a nucleotide in tRNA C. change in a nucleotide in rRNA D. change in a nucleotide in DNA E. change in a pro | D. change in a nucleotide in DNA |
Most microbes grow optimally at or around 37 C. True OR False | True |
Microbial growth refers to an increase in the size of individual microbes. True or False | False |
The generation time is the amount of time required for a population of bacteria to double in size. True or False | True |
Which phase of microbial growth is characterized by a decline in population size? A. lag phase B. growth phase C. stationary phase D. death phase | D. death phase |
Which of the following terms refers to the destruction and removal of ALL forms of microbial life. A. Sterilization B. disifection C. antisepsis D. sanitation | A. Sterilization |
The term trace elements refers to A. the elements CHONPS B. vitamins C. nitrogen, phosphorus, and sulfur D. small mineral requirements E. toxic substances | D. small mineral requirements |
Which one of the following temperatures is most ideal for a mesophile? A. -50 C B. 9 C C. 60 C D. 0 C E. 37 C | E. 37 C |
All of the following are true about agar except A. It is a source of nutrients in culture media B. it is a polysaccharide C. It liquifies at 100 C D. It solidifies at approximately 40 C E. It is metabolized by few bacteria | A. It is a source of nutrients in culture media |
Which of the following types of media would not be used to culture aerobes? A. selective media B. reducing media C. enrichment media D. differential media E. complex media | B. reducing media |
An organism that has peroxidase and superoxide dismutase but lacks catalase is most likely an A. aerobe B. aerotolerant anaerobe C. obligate anaerobe | B. aerotolerant anaerobe |
Which of the following does not kill endospores? A. autoclaving B. incineration C. hot-air sterilization D. pasteurization E. all of the above kill endospores | D. pasteurization |
Which of the following is most effective for sterilizing matresses and plastic Petri dishes? A. chlorine B. ethylene oxide C. glutaraldehyde D. autoclaving E. nonionizing radiation | B. ethylene oxide |
Which of these disinfectants does not act by disrupting the plasma membrane? A. phenolics B. phenol C. quaternary mmonium compounds D. halogens E. biguanides | D. halogens |
Which of the following is not a characteristic of quaternary ammonium compounds? A. bactericidal against gram-positive bacteria B. sporicidal C. amoebicidal D. fungicidal E. kills enveloped viruses | B. sporicidal |
Immunity is the ability to fight off disease. True or False | True |
Phagocytosis is the ingestion of a particle or cell by another cell. True or False | True |
Which of the following are part of the non-specific defense system? A. complement system B. inflammation C. phagocytosis D. mucus membranes E. all of the above | E. all of the above |
A substance that induces a specific immune response is ... A. a pathogen B. an antigen C. a hormone D. a cytokine | B. an antigen |
What type of cell contain CD4 receptors and play a pivotal role in activating both humoral and cell-mediated immunity? A. helper T cells B. helper B cells C. plamsa cells D. natural killer cells | A. helper T cells |
Legionella uses C3b receptors to enter monocytes. This ... A. prevents phagocytosis B. degrades complement C. inactivates complement D. prevents inflammation | A. prevents phagocytosis |
Chlamydia can prevent the formation of phagolysosomes, and therefore can ... A. avoid being phagocytized B. avoid compliment fixation C. prevent adherence D. avoid being digested E. none of the above | D. avoid being digested |
If the following are placed in the order of occurrence, which would be the third step of phagocytosis? A. Emigration B. digestion C. formation of phagosome D. formation of phagolysosome E. margination | C. formation of phagosome |
If the following are placed in order of occurrence, which would be the third step in the complement system? A. activation of C5-C9 B. cell lysis C. anatigen-antibody reaction D. activation of C3 | D. activation of C3 |
A human host can prevent a pathogen from getting enough iron by ... A. reducing dietary intake B. binding iron with transferrin C. binding iron with hemoglobin D. excreting excess iron Points Received: 2 of 2 | B. binding iron with transferrin |
Helicobacter pylori uses the enzyme urease to counteract a chemical defense in the human organ in which it lives. This chemical defense is ... A. lysosome B. hydrochloric acid C. superoxide dismutase D. complement | B. hydrochloric acid |
Protection provided by injection of a toxoid is ... A. Innate resistance B. naturally acquired active immunity C. naturally acquired passive immunity D. artificially acquired active immunity E. artificially acquired passive im | D. artificially acquired active immunity |
A partical capable of activating the immune system is ... A. an antigen B. an antibody C. a microbe D. a macrobe | A. an antigen |
Helper T cells activate B cell proliferation. True or False | True |
Humoral immunity involved antibodies that are produced by plasma T cells. True or False | False |