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Exam 3 for microbiology

all of exam 3
STUDY
PLAY
A commensal bacterium
May also be an opportunistic bacterium
Which of the following statements is TRUE?
A) At least one member must not benefit in a symbiotic relationship.
B) Members of a symbiotic relationship cannot live without each other.
C) A parasite is not in symbiosis with its host.
D) Symbiosis refers to different organisms living together and benefiting from each other.
E) At least one member must benefit in a symbiotic relationship.
E) at least one member must benefit in a symbiotic relationship
A nosocomial infection is
aquired during the course of hospitalization
The major significance of Robert Koch's work is that
microrganism can cause disease
Which of the following is NOT a verified exception in the use of Koch's postulates?
A) Some diseases have poorly defined etiologies.
B) Some pathogens can cause several disease conditions.
C) Some human diseases have no other known animal host.
D) Some diseases are not caused by microbes.
E) Some diseases are noncommunicable.
E) some diseases are noncommunicable
Which of the following diseases is NOT spread by droplet infection?
A) botulism
B) tuberculosis
C) measles
D) the common cold
E) diphtheria
A) botulism
Biological transmission differs from mechanical transmission in that biological transmission
Involves specific diseases
Focal infections initially start out as
local infections
The rise in herd immunity amongst a population can directly attributed to
vaccinations
Koch observed Bacillus anthracis multiplying in the blood of cattle. What is this condition called?
septicemia
Which one of the following does NOT contribute to the incidence of nosocomial infections?
A) antibiotic resistance
B) lapse in aseptic techniques
C) gram-negative cell walls
D) lack of handwashing
E) lack of insect control
c) gram negative cell walls
Transient microbiota differ from normal microbiota in that transient microbiota
are present for relatively a short time
Which of the following statements about nosocomial infections is FALSE?A) They occur in compromised patients.
B) They may be caused by opportunists.
C) They may be caused by drug-resistant bacteria.
D) They may be caused by normal microbiota.
E) The patient was infected before hospitalization.
e) the patient was infected before hospilization
One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in
increased susceptability to disease
Which of the following is NOT a reservoir of infection?
A) a sick person
B) a healthy person
C) a sick animal
D) a hospital
E) None of the answers is correct; all of these can be reservoirs of infection.
E) none
Which of the following is NOT a communicable diseases?
A) malaria
B) AIDS
C) tuberculosis
D) tetanus
E) typhoid fever
D) tetanus
Which of the following is a fomite?
a hypodermic needle
Which of the following statements about biological transmission is FALSE?A) The pathogen reproduces in the vector.
B) The pathogen may enter the host in the vector's feces.
C) Houseflies are an important vector.
D) The pathogen may be injected by the bite of the vector.
E) The pathogen may require the vector as a host
C) house flies are an important vector
Which of the following definitions is INCORRECT?
A) acute: a short-lasting primary infection
B) inapparent: infection characteristic of a carrier state
C) chronic: a disease that develops slowly and lasts for months
D) primary infection: an initial illness
E) secondary infection: a long-lasting illness
E) secondary infections: a long lasting illness
The science that deals with when diseases occur and how they are transmitted is called
epidemiology
shows the incidence of influenza during a typical year. Which letter on the graph indicates the endemic level? GRAPH
D
Emergence of infectious diseases can be attributed to all of the following EXCEPT
A) antibiotic resistance.
B) climatic changes.
C) new strains of previously known agents.
D) ease of travel.
E) None of the answers is correct; the emergence of infectious diseases can be attributed to all of these.
E) none the emergence of infections can be attributted to all of these
Which of the following pairs is mismatched?
A) malaria vector
B) salmonellosis vehicle transmission
C) syphilis direct contact
D) influenza droplet infection
E) None of the pairs is mismatched.
none of the pairs are mismatched
Which of the following can contribute to postoperative infections?
using syringes more than once, errors in aseptic technique, normal microbiota in operating staff, antibiotic resistance
A researcher has performed a prospective study on the disease tetanus. To which specific kind of epidemiological study is this referring?
descriptive
The CDC is located in
Atlanta GA
A disease in which the causative agent remains inactive for a time before producing symptoms is referred to as
latent
A needlestick is an example of
fomite
Which of the following is NOT a predisposing factor of disease?
A) lifestyle
B) genetic background
C) climate
D) occupation
E) None of the answers are correct; all of these are predisposing factors of disease.
In which of the following diseases can gender be considered a viable predisposing factor?
A) urinary tract infections
In which of the following patterns of disease does the patient experience no signs or symptoms?
A) UTI
The most frequently used portal of entry for pathogens is the
mucus membranes of the respiratory tract
The ability of some microbes, such as Trypanosoma or Giardia to alter their surface molecules and evade destruction by the host's antibodies is called
antigenic variation
Most pathogens that gain access through the skin
enter through hair follicles and sweat ducts
The ID50 is
the dose that will cause an infection 50% of the test population
All of the following contribute to a pathogen's invasiveness EXCEPT
A) toxins.
B) capsules.
C) cell wall components.
D) hyaluronidase.
E) coagulases.
toxins
Which of the following statements is FALSE?
A) Leukocidins destroy neutrophils.
B) Hemolysins lyse red blood cells.
C) Hyaluronidase breaks down substances between cells.
D) Kinase destroys fibrin clots.
E) Coagulase destroys blood clots.
E) Coagulase destroys blood clots
Which of the following statements about exotoxins is generally FALSE?
A) They are more potent than endotoxins.
B) They are composed of proteins.
C) They are resistant to heat.
D) They have specific methods of action.
E) They are produced by gram-positive bacteria.
C) they are resistant to heat
Endotoxins are
Part of the gram negative cell wall
Which of the following is NOT a membrane-disrupting toxin?
A) A-B toxin
B) hemolysin
C) leukocidin
D) streptolysin O
E) streptolysin S
A-B toxin
Cytopathic effects are changes in host cells due to
viral infections
Which of the following does NOT contribute to the symptoms of a fungal disease?
cell walls
All of the following are methods of avoiding host antibodies EXCEPT
A) antigenic changes.
B) IgA proteases.
C) invasins.
D) membrane-disrupting toxins.
E) inducing endocytosis.
D) membrane disrupting toxins
The fimbriae of Neisseria gonorrhea and enteropathogenic E. coli are examples of
adhesisns and ligands
All of the following are examples of entry via the parenteral route EXCEPT
hair follicle
Superantigens produce intense immune responses by stimulating lymphocytes to produce
cytokines
Botulism is caused by ingestion of a proteinaceous exotoxin; therefore, it can easily be prevented by
boiling food prior to consumption
All of the following organisms produce exotoxins EXCEPT
A) Salmonella typhi.
B) Clostridium botulinum.
C) Corynebacterium diphtheriae.
D) Clostridium tetani.
E) Staphylococcus aureus.
salmonella typhi
Which of the following cytopathic effects is cytocidal?
A) inclusion bodies
B) giant cells
C) antigenic changes
D) transformation
E) release of enzymes from lysosomes
E) release of enzymes from lysosomes
All of the following are used by bacteria to attach to host cells EXCEPT
A) M protein.
B) ligands.
C) fimbriae.
D) capsules.
E) A-B toxins.
A-B toxins
Symptoms of protozoan and helminthic diseases are due to
E) tissue damage due to growth of the parasite on the tissue, wast products excreted by the parasite and products released from damaged tissues
Which of the following statements about staphylococcal enterotoxin is FALSE?
A) It causes vomiting.
B) It causes diarrhea.
C) It is an exotoxin.
D) It is produced by Staphylococcus aureus growing in the host's intestines.
E) It is a superantigen.
D) it is produced by staphlyococcues aureus growing in the host intestines
Which of the following contributes to the virulence of a pathogen?
A) numbers of microorganisms that gain access to a host
B) evasion of host defenses
C) toxin production
D) numbers of microorganisms that gain access to a host and evasion of host defenses
E) numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production
E)numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production
Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages
give new genes sequences to the host bacteria
Polio is transmitted by ingestion of water contaminated with feces containing polio virus. What portal of entry does polio virus use?
mucus membranes only
Bacteria that cause periodontal disease have adhesins for receptors on streptococci that colonize on teeth. This indicates that
Streptococcal colonization is necessary for periodontal disease
In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes
A decrease in blood pressure
What type of immunity results from vaccination?
Artificial acquired active immunity
What type of immunity results from transfer of antibodies from one individual to a susceptible individual by means of injection?
artificially acquired passive immunity
What type of immunity results from recovery from mumps?
naturally acquired active immunity
Which of the following is the best definition of epitope?
specific regions on antigens that interact with antibodies
Newborns' immunity due to the transfer of antibodies across the placenta is an example of
naturally acquired passive immunity
Which of the following statements is NOT a possible outcome of antigen-antibody reaction?
clonal deletion
Large antibodies that agglutinate antigens are
IgM
All of the following are true of hypersensitivity EXCEPT
A) it occurs in the presence of an antigen.
B) it is synonymous with "allergy."
C) it occurs when an individual is exposed to an allergen for the first time.
D) it is due to an altered immune response.
E) it requires previous exposure to an antigen
C) it occurs when an individual is exposed to an allergen for the first time.
The chemical mediators of anaphylaxis are
A) found in basophils and mast cells.
B) antibodies.
C) antigens.
D) antigen-antibody complexes.
E) the proteins of the complement system.
A)found in basophils and mast cells
Which of the following may result from systemic anaphylaxis?
A) hay fever
B) asthma
C) shock
D) hives
E) immunodeficiency
shock
Rheumatoid arthritis is due to deposition of
E) complexes of IgM and IgG and also complement in joints
Allergic contact dermatitis is due to
sensitized T cells
Hemolytic disease of the newborn can result from an
RH- mother with an RH+ fetus
Worldwide, the primary method of transmission of HIV is
heterosexual intercourse
Which of the following is the least likely vaccine against HIV?
attenuated virus
Which of the following regions has the greatest distribution of HIV infection and AIDS in the world?
sub-Saharan Africa
The initial symptom of HIV infection is
lymphadenopathy
Penicillin was considered a "miracle drug" for all of the following reasons EXCEPT
it was the first antibiotic
Most of the available antimicrobial agents are effective against
bacteria
Antimicrobial peptides work by
disrupting the plasma membrane
Which of the following antimicrobial agents has the fewest side effects?
penicillin
Which of the following methods of action would be bacteriostatic?
A) competitive inhibition with folic acid synthesis
B) inhibition of protein synthesis
C) injury to plasma membrane
D) inhibition of cell wall synthesis
E) competitive inhibition with DNA gyrase
B) inhibition of protein synthesis
More than half of our antibiotics are
produced by bacteria
Which of the following organisms would MOST likely be sensitive to natural penicillin?
Streptocuccus pyogenes
Drug resistance occurs
when antibiotics are used indiscriminately
The most effective antibiotic tested was GRAPH
D
The antibiotic that exhibited bactericidal action was
GRAPH
the answer cannot be determined by graph
Which antibiotic would be most useful for treating a Salmonella infection? graph
The answer cannot be determined by graph
In the presence of penicillin, a cell dies because
it undergoes lysis
plasma cells are activated by
an antigen
antibodies found in mucus, saliva, and tears are
IgA
the antibodies found on the surface of B cells, and which always exist as monomers are
IgD
antibodies that bind to large parasites are
IgE
in addition to IgG, the antibodies that can fix complement are
IgM