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BioSc221/325
Exam 4
Name ______________________________
Multiple choice. (1 point each) Choose the one best answer to each of the following questions.
_____ What stimulates T-cell proliferation in response to the presence of a pathogen?
A. protein-protein interaction between CD-4 and MHC I or II.
B. protein-protein interaction between the T-cell receptor and MHCI or II.
C. cytokines released by the APC.
D. cytokines released by B-cells
____ A cell that recognizes microbial antigens displayed on a macrophage MHCII complex eventually leading to
stimulation of antibody production.
A. cytotoxic T cell
B. B cell
C. macrophage
D. T helper cell
_____ A virus which becomes avirulent through the loss of virulence factors (often occurring due to multiple
passages through a different host) is described as __.
A. adjuvent
B. attenuated
C. acellular
D. amplified
_____ Which of the following antibody based serological tests involves separation of proteins by electrophoresis
which is then used for detection of antibodies in serum?
A. ELISA
B. Agglutination
C. Western Blot
D. All of the above
____ Long lived T or B cells produced during an initial immune response that can respond quickly to subsequent
infections.
A. macrophages
B. antigen presenting cells
C. cytotoxic cells
D. memory cells
____ A vaccine generated by fusing a polysaccharide to an immunogenic protein is called a __.
A. subunit vaccine
B. conjugate vaccine
C. toxoid
D. toxinoid
____ Why is Salmonella typhimurium being used for the development of a recombinant vaccine against Cholera?
A. Salmonella typhimurium is non-pathogenic.
B. Salmonella typhimurium closely resembles Vibrio cholera
C. Salmonella typhimurium targets the same tissues as Vibrio cholera.
D. Salmonella typhimurium should not being used for recombinant vaccine development.
____ Vaccines are successful in preventing disease due to __.
A. the production of large quantities of antibodies that remain in the bloodstream and attach subsequent invading
microbes.
B. production of long-lived "memory" cells that can quickly respond to invading microbes.
C. production of additional neutrophils that can seek out and destroy invading microbes.
D. production of more complement proteins that can increase the bodies response to subsequent invading microbes
_____ What is the primary cause of “walking” pneumonia?
A. Klebsiella pneumoniae
B. Streptocococcus pneumoniae
C. Mycoplasma pneumoniae
D. Haemophilus influenza
_____ Why is malaria also called blackwater fever?
A. malaria arises from ingesting contaminated water.
B. malaria arises from mosquitos that thrive on “black” water
C. malaria results in the release of hemoglobin which turns black in the patients urine
D. malaria causes the patient to black-out due to the high fever
_____ What unusual compound is found in the membranes of Mycoplasma pneumoniae?
A. mycolic acid
B. teichoic acid
C. uronic acid
D. cholesterol
_____ What surface protein, expressed at higher levels in response to cytokines. is the cellular target for
rhinoviruses?
A. MHC I
B. MHC II
C. ICAM I
D. EGF 1
_____ What arthropod borne disease is also known as “breakbone fever”
A. malaaria
B. dengue fever
C. the plague
D. lyme disease
_____ Most bacteria that cause pneumonia have what virulence factor in common?
A. capsules
B. hemolysins
C. ability to multiply inside phagocytes
D. toxins that kill alveolar macrophages
_____ Anthrax, brucellosis and rabies have been “controlled” by __.
A. immunization of their domestic animal hosts
B. elimination of intermediate hosts
C. slaughter of all infected animals
D. development of effective antibiotics
_____ A factor that has allowed new diseases to emerge and old ones to re-emerge is
A. homeless shelters.
B. overuse or incorrect use of antibiotics.
C. cancer chemotherapy.
D. international travel.
E. All of the above have contributed.
_____ The two species of bacteria most commonly associated with burn wound infections are
A. Staphylococcus aureus and Streptococcus pyogenes
B. Staphylococcus aureus and Pseudomonas aeruginosa.
C. Streptococcus pyogenes and Pseudomonas aeruginosa.
D. Staphylococcus epidermidis and Pseudomonas aeruginosa.
E. Staphylococcus epidermidis and Bacteroides fragilis.
_____ Cancer chemotherapy increases risk of infection because it kills
A. neutrophils
B. memory T cells
C. liver cells.
D. skin cells.
E. antibody-producing cells
_____ What distinguishes do endotoxins from exotoxins?
A. endotoxins are proteins
B. endotoxins are heat stable
C. endotoxins ADP-ribosylate host enzymes
D. endotoxins create holes in host cell membranes
E. endotoxins induce the stimulation of multiple helper T-cells
_____ Which of the following vaccines is/are accurately described as a subunit vaccine?
A. Vaccine composed of killed bacteria.
B. Vaccine composed of a pilus protein
C. Vaccine composed of a live attenuated virus.
D. Antibodies injected into a non-immune person exposed to a disease
_____ Toxoid vaccines such as the vaccines against diphtheria and tetanus
A. preferentially stimulate a cytotoxic T cell response
B. are designed to elicit an activated macrophage response
C. are composed of polysaccharides.
D. elicit antibodies that inactivate bacterial protein toxins
E. must be given orally
_____ A malarial infection is initiated when a mosquito injects the following form of the parasite when it bites a
human.
A. merozoite
B. microgamete
C. macrogamete
D. sporozoite
_____ All of the following are transmitted by arthropods, EXCEPT
A. Dengue virus.
B. Plasmodium vivax.
C. Borrelia burgdorferi
D. Ehrlichia spp.
E. Bacillus anthracis.
_____ The lethal form of anthrax is associated with
A. production of spores.
B. infection of skin lesions.
C. production of a two-component protein toxin.
D. infection of bones and joints.
E. ingestion of the bacteria.
_____ Fever and shaking chills in a malaria attack are the result of
A. lysis of red blood cells when merozoites escape.
B. excretion of hemoglobin from lysed red blood cells.
C. attachment of the malaria parasite to endothelial cells lining blood vessels.
D. release of parasites from liver cells.
E. fusion of micro- and macrogametes.
_____ Characteristics of microorganisms that cause nosocomial infections today are different from those in earlier
decades. Characteristics of the microbes that cause such infections today are
A. An equal mixture of gram-positive and gram-negative species.
B. Predominantly gram-negative.
C. Predominantly yeasts.
D. Likely to be resistant to antimicrobial agents.
Short answer. (1 point each)
The diagram to the left shows the results a a DNA
based technique used to distinguish specific strains
of a bacterial species. Each lane represents the
results of a different isolate of the same species.
What is the name of this technique?
What is the advantage of using the above technique compared to standard biochemical tests for tracking the source
of an outbreak?
The figure to the right illustrates the results of a test to
determine the Minimal Inhibitory Concentration (MIC)
of an antibiotic that stops the growth of a strain of
Streptococcus pyogenes isolated from a patient. After
incubation gray indicates growth and colorless indicates
no growth. What is the MIC of this antibiotic for this
particular strain of Streptococcus pyogenes?
The figure to the left shows the results of a test for antibiotic sensitivity by the
disk diffusion method. Is it possible to distinguish which of the three
antibiotics is most effective against the organism? If so, which one? If not,
explain why?
Why are some viruses harder to make vaccines against compared to others?
What is herd immunity?
Describe one example of passive immunization.
What kinds of social reforms in the late 1800s led to a decline in the incidence of TB?
What are some factors in modern society that could potentially lead to new or re-emerging diseases?
What is an endemic disease?
What are our bodies defenses against lung infections?
How do new strains of influenza virus arise?
Short Essay Questions. Please answer four of the following five short essay questions (6 points each - 6 bonus
points possible for answering all 5 questions)
Select any microbial disease and explain how Koch’s postulates would be used to verify that a specific microbe
causes that disease.
Describe the steps in the development of tuberculosis.
Design a pathogen. Select a target tissue/cell type, reservoir, mode of entry, mode of dissemination etc.
Describe the life-cycle and mode of transmission of the plaque.
Draw a(n) LD50 or ID50 curve for a pathogen that requires about 10 4 cells/viruses to cause a measurable effect. Be
sure to label all parts of the graph. Add to the graph two additional curves representing 1) a variant strain in which a
key virulence factor has been disrupted and 2) a second variant strain in which an additional virulence factor has
been added which makes the strain more virulent.