Chester Clinic

 

Practcie quiz 3

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Agents that kill bacteria are said to be A) bacteriostatic.
B) inhibitory.
C) bacteriocidal.
D) all of the above.
2) Compared with decontamination, disinfection is A) equally aggressive.
B) more aggressive.
C) less aggressive.
D) either more or less aggressive, depending on the situation in question.
3) The complete elimination of all microorganisms, including viruses, is called A) sterilization.
B) decontamination.
C) disinfection.
D) any of the above, depending on the circumstances.
4) The process by which macromolecules lose their structure and ability to function is called A) thermal death.
B) sterilization.
C) denaturation.
D) none of the above.
5) Which statement is TRUE about heat sterilization? A) The amount of water in a substance is a major factor in heat resistance.
B) High concentrations of sugars and salts influence sterilization time.
C) Microbial death is more rapid at an acidic pH.
D) All of the above are true.
6) UV radiation is antimicrobial, because A) energy present causes modifications or breaks in the DNA molecules.
B) radiation generates magnetic poles that denature the cellular components.
C) radiation generates significant amounts of heat within the given cell.
D) all of the above are true.
7) Common radioactive isotopes for sterilization are A) cesium and potassium.
B) cobalt and cesium.
C) cobalt and potassium.
D) cobalt and iodine.
8) Ergosterol inhibitors specifically target A) eukaryotes.
C) bacteria.
9) A filter is most often used in scanning electron microscopy.
B) nucleation track 10) Semisynthetic antibiotics A) are natural antibiotics that have been chemically modified in the laboratory.
B) have an artificially constructed core that stimulates the production of "natural products." C) are natural antibiotics that have been purified by artificial means.
D) are found in nature, but their rate of production is enhanced in the laboratory.
11) Important targets of antibiotics in Bacteria are A) the cytoplasmic membrane.
B) the cell wall.
C) DNA replication and transcription elements.
D) all of the above.
12) Antimicrobial drugs are often grouped according to A) molecular structure.
B) mechanism of action.
C) spectrum of antimicrobial activity.
D) all of the above.
13) The β-lactam antibiotics A) inhibit cell wall synthesis.
B) inhibit plasma membrane synthesis.
C) inhibit protein synthesis.
D) prevent chromosomal replication.
14) The most successful agents used for antiviral chemotherapy are A) ATP reductase inhibitors.
B) nucleotide analogs.
C) nucleoside analogs.
D) protein synthesis inhibitors.
15) Erythromycin acts as a(n) A) inhibitor of ribosome production.
B) protein synthesis inhibitor at the level of the 50S subunit of the ribosome.
C) protein synthesis inhibitor at the level of the 30S subunit of the ribosome.
D) nucleic acid enzyme inhibitor.
16) Penicillin was considered a "miracle drug" for all of the following reasons EXCEPT A) It doesn't affect eukaryotic cells.
B) It inhibits gram-positive cell wall synthesis.
C) It has selective toxicity.
D) It kills bacteria.
E) It was the first antibiotic.
17) A drug that inhibits mitosis, such as griseofulvin, would be more effective against A) Gram-positive bacteria.
B) Mycobacteria.
C) Gram-negative bacteria.
D) Wall-less bacteria.
18) The antibiotic tetracycline binds to the 30S subunit of the ribosome as shown in Figure 20.1. The A) Prevent transcription.
B) Stop the ribosome from moving along the mRNA.
C) Prevent attachment of tRNA and mRNA.
D) Prevent peptide bond formation.
E) Prevent attachment of tRNA.
19) The antibiotic cycloheximide binds to the 60S subunit of the ribosome as shown in Figure 20.2.
A) Prevent peptide bond formation in prokaryotes.
B) Prevent ribosome formation in bacteria.
C) Prevent transcription in prokaryotes.
D) Prevent mRNAribosome binding in eukaryotes.
E) Prevent polypeptide elongation in eukaryotes.
20) The antibiotic chloramphenicol binds to the 50S subunit of the ribosome as shown in Figure 20.3.
A) Stop the ribosome from moving along the mRNA.
B) Prevent transcription.
C) Prevent peptide bond formation.
D) Prevent attachment of tRNA.
E) Prevent polypeptide formation in eukaryotes.
21) Which of the following antibiotics are used to treat fungal infections? 1. Aminoglycosides2. Cephalosporins3. Griseofulvin4. Polyenes5. Bacitracin E) All of the antibiotics 22) Protozoan and helminthic diseases are difficult to treat because A) They don't reproduce.
B) They replicate inside human cells.
C) They have more genes than bacteria.
D) They don't have ribosomes.
E) Their cells are structurally and functionally similar to human cells.
23) In the presence of penicillin, a cell dies because A) It plasmolyzes.
B) It undergoes osmotic lysis.
C) It lacks a cell membrane.
D) It lacks a cell wall.
E) Its contents leak out.
24) A gene is best defined as A) A sequence of nucleotides in RNA that codes for a functional product.
B) Three nucleotides that code for an amino acid.
C) A segment of DNA.
D) A sequence of nucleotides in DNA that codes for a functional product.
E) A transcribed unit of DNA.
25) DNA is constructed of A) Nucleotides bonded AC and GT.
B) Two strands of identical nucleotides with hydrogen bonds between them.
C) A single strand of nucleotides with internal hydrogen bonding.
D) Two strands of nucleotides running antiparallel.
E) None of the above.
26) Transformation is the transfer of DNA from a donor to a recipient cell A) By cell-to-cell contact.
B) By crossing over.
C) As naked DNA in solution.
D) By a bacteriophage.
E) By sexual reproduction.
27) Genetic change in bacteria can be brought about by A) Transformation.
B) Mutation.
C) Conjugation.
D) Transduction.
E) All of the above.
28) Synthesis of a repressible enzyme is stopped by A) The substrate binding to the repressor.
B) The end-product binding to the promoter.
C) The corepressor-repressor binding to the operator.
D) The corepressor binding to the operator.
E) The allosteric transition.
29) An enzyme that copies DNA to make a molecule of RNA is A) DNA ligase.
B) Restriction enzyme.
C) RNA polymerase.
D) Transposase.
E) DNA polymerase.
30) An enzyme that cuts double-stranded DNA at specific nucleotide sequences.
B) RNA polymerase D) Restriction enzyme E) DNA polymerase 31) In transcription, A) Proteins are made.
B) DNA is replicated.
C) RNA is copied to DNA.
D) DNA is copied to RNA.
E) DNA is changed to RNA.
32) Repair of damaged DNA might be viewed as a race between an endonuclease and B) DNA polymerase.
C) Helicase.
D) Methylase.
E) DNA ligase.
33) A nosocomial infection is A) Always caused by medical personnel.
B) Always caused by pathogenic bacteria.
C) Acquired during the course of hospitalization.
D) Always present but is inapparent at the time of hospitalization.
E) Only a result of surgery.
34) Koch's postulates don't apply to all diseases because A) Some microorganisms can't be observed.
B) Not all diseases are caused by microorganisms.
C) Some microorganisms can't be cultured in laboratory media.
D) Some microorganisms don't cause the same disease in laboratory animals.
E) Some microorganisms cause different symptoms under different conditions.
35) Which of the following diseases is NOT spread by droplet infection? 36) Mechanical transmission differs from biological transmission in that mechanical transmission A) Involves fomites.
B) Doesn't involve specific diseases.
C) Doesn't work with noncommunicable diseases.
D) Requires direct contact.
E) Doesn't require an arthropod.
37) Which of the following definitions is incorrect? A) Pandemic  a disease that affects a large number of people in the world in a short time B) Sporadic  a disease that affects a population occasionally C) Epidemic  fraction of the population having a disease at a specified time D) Endemic  a disease that is constantly present in a population E) Incidence  number of new cases of a disease 38) Which of these infections can cause septicemia? A) Focal infection B) Systemic infection D) Local infection 39) Transient microbiota differ from normal microbiota because transient microbiota A) Are found in a certain location on the host.
B) Are acquired by direct contact.
C) Never cause disease.
D) Are present for a relatively short time.
E) Cause diseases.
40) One effect of washing regularly with antibacterial agents is the removal of normal microbiota.
This can result in A) Body odor.
B) Normal microbiota returning immediately.
C) Increased susceptibility to disease.
D) Fewer diseases.
E) No bacterial growth because washing removes their food source.
41) Which of the following is NOT a reservoir of infection? A) A healthy person E) All of the above can be reservoirs of infection.
42) Which of the following is NOT a communicable diseases? 43) Which of the following is a fomite? C) A hypodermic needle D) Droplets from a sneeze 44) Which of the following definitions is incorrect? A) Primary infection  an initial illness B) Secondary infection  a long-lasting illness C) Inapparent  infection characteristic of a carrier state D) Acute  a short-lasting primary infection E) Chronic  a disease that develops slowly and lasts for months 45) A cold transmitted by a facial tissue is an example of A) Droplet transmission.
B) Vehicle transmission.
E) Direct contact.
46) Symptoms of disease differ from signs of disease in that symptoms A) Are changes felt by the patient.
B) Always occur as part of a syndrome.
C) Are changes observed by the physician.
D) Are specific for a particular disease.
E) None of the above.
47) Influenza transmitted by an unprotected sneeze is an example of B) Direct contact.
C) Vehicle transmission.
D) Droplet transmission.
48) A sexually transmitted disease is an example of A) Droplet transmission.
C) Direct contact.
D) Vehicle transmission.
49) Gastroenteritis acquired from roast beef is an example of A) Direct contact.
B) Vehicle transmission.
E) Droplet transmission.
50) A needlestick is an example of A) Droplet transmission.
D) Direct contact.
E) Vehicle transmission.
51) Legionellosis transmitted by a grocery store mist machine is an example of A) Vehicle transmission.
C) Droplet transmission.
E) Direct contact.
During a 6-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever≥39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints,fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii.
Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positivefor C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each ofthe previous 3 years.
52) Situation 14.1 is an example of A) A zoonosis.
B) Human reservoirs.
C) A nonliving reservoir.
D) A focal infection.
E) A vector.
53) In Situation 14.1, the etiologic agent of the disease is A) Coxiella burnetii. E) Pneumonia.
54) In Situation 14.1, the method of transmission of this disease was A) Vector-borne.
C) Direct contact.
D) Indirect contact.
55) The yeast Candida albicans does not normally cause disease because of A) Parasitic bacteria.
B) Commensal bacteria.
C) Other fungi.
D) Antagonistic bacteria.
E) Symbiotic bacteria.
56) Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery.
This is an example of a A) Communicable disease.
B) Sporadic disease.
C) Latent infection.
D) Nosocomial infection.
E) None of the above.
57) The graph in Figure 14.3 shows the incidence of polio in the United States. The period between 1945 and 1955 indicates A) An endemic level.
B) An epidemic level.
C) A communicable disease.
D) A pandemic.
E) A sporadic infection.
58) The most frequently used portal of entry for pathogens is the A) Mucous membranes of the gastrointestinal tract.
C) Parenteral route.
D) Mucous membranes of the respiratory tract.
E) All are used equally.
59) The ID50 is a A) Dose that will kill 50% of the test population.
B) Dose that will cause an infection in 50% of the test population.
C) Dose that will cause an infection in some of the test population.
D) Measure of pathogenicity.
E) Dose that will kill some of the test population.
60) Which of the following diseases is NOT usually contracted by the respiratory route? B) Whooping cough C) Infectious hepatitis E) All of the above are usually contracted by the respiratory route.
61) Which of the following organisms causes the most severe disease? A) Shigella B) Treponema pallidum C) E. coli O157:H7 D) Rhinovirus 62) The mechanism by which gram-negative bacteria can cross the blood-brain barrier? A) Producing fimbriae C) Inducing endocytosis D) Producing toxins E) All of the above 63) Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides A) Polypeptide A would bind to target cells.
B) Polypeptide B would not be able to enter the cells.
C) Polypeptide A would enter the cells.
D) Vibrio would bind to target cells.
E) Vibrio would not produce cholera toxin.
64) Poliovirus is ingested and gains access to tissues by which portal of entry? C) Mucous membranes D) All of the above E) None of the above 65) Septic shock due to gram-positive bacteria is caused by B) A-B toxins.
C) Membrane-disrupting toxins.
D) Superantigens.
E) Erythrogenic toxin.
66) Which of the following statements about staphylococcal enterotoxin is false? A) It is an exotoxin.
B) It is a superantigen.
C) It causes diarrhea.
D) It is produced by Staphylococcus aureus growing in the host's intestines.
E) It causes vomiting.
67) Botulism is caused by a proteinaceous exotoxin; therefore it can easily be prevented by A) Boiling food prior to consumption.
B) Administering antibiotics to patients.
C) Preventing fecal contamination of food.
D) Filtering food.
E) Not eating canned food.
68) Which of the following CANNOT be used for adherence? A) Cell membrane mannose 69) Siderophores are bacterial proteins that compete with animal A) Transferrin.
B) Receptors.
C) Red blood cells.
D) Antibodies.
E) White blood cells.
70) Cytopathic effects are changes in host cells due to A) Bacterial infections.
B) Protozoan infections.
C) Helminthic infections.
D) Viral infections.
E) Fungal infections.
71) Which of the following is NOT a membrane-disrupting toxin? A) Streptolysin O C) Streptolysin S 72) Endotoxins are A) Part of the gram-negative cell wall.
B) Associated with gram-positive bacteria.
C) A-B toxins.
D) Specific in their method of action.
E) Excreted from the cell.
73) Which of the following statements is false? A) Kinase destroys fibrin clots.
B) Leukocidins destroy neutrophils.
C) Coagulase destroys blood clots.
D) Hemolysins lyse red blood cells.
E) Hyaluronidase breaks down substances between cells.
74) In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes A) An increase in red blood cells.
B) The disease to subside.
D) A gram-negative infection.
E) A decrease in blood pressure.
75) Patients developed inflammation a few hours following eye surgery. Instruments and solutions were sterile, and the Limulus assay was positive. The patients' inflammation was due to A) Viral infection.
B) Bacterial infection.
C) Endotoxin.
D) Exotoxin.
E) Can't tell.

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