micro final hw – Flashcards
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If a person turns their ankle, how would one determine if damage to the tissue in the ankle has occurred a The ankle is red. b The ankle is red, swollen, and warm to the touch. c The ankle swells. d The ankle is very warm to the touch.
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The ankle is red, swollen, and warm to the touch.
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What is the function of inflammation in response to a burn from a hot iron a To limit the effects of the agent on the rest of the body b To destroy the agent causing injury, to limit the effects of the agent on the rest of the body, and to repair the damaged tissue c To repair the damaged tissue d To destroy the agent causing injury
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To repair the damaged tissue
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What does the plasma membrane of a phagocyte attach to on a microorganism a Pseudopods b Lysosomes c Phagosomes d Glycoproteins
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Glycoproteins
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The process by which a phagocyte moves toward a chemical signal at the site of an infection is called a chemotaxis. b exocytosis. c digestion. d adherence. e elimination.
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chemotaxis
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Which of the following phagocytic processes occurs last in the sequence a Exocytosis b Adherence c Formation of the phagolysosome d Chemotaxis of the phagocyte to the site of infection
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Exocytosis
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What is the role of opsonins a They are present on the surface of phagocytes. b They attract phagocytes to the location of infection. c They aid in the formation of the phagolysosome. d They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.
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They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.
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What is a phagolysosome? a) A vesicle containing only digestive enzymes and other antimicrobial compounds. b) The structure that results from the fusion of a phagosome and a lysosome. c) A protein that covers the surface of an invading microbe, making it easier for the phagocyte to ingest. d) A vesicle containing only an engulfed invading microorganism.
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The structure that results from the fusion of a phagosome and a lysosome.
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How does cytolysis occur via the complement pathway a) Stimulation of the inflammatory response b) Formation of the MAC in invading cells, killing them c) Triggering the release of histamine d) Disrupting cell wall of pathogens
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Formation of the MAC in invading cells, killing them
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Which complement protein is used as an opsonin a) C5b b) C4a c) C2a d) C3b e) C3a f) C7
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C3b
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If a person lacked the ability to form C5, what direct result of complement could still occur a) Opsonization b) Chemotaxis c) Cytolysis
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Opsonization
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If a person could not form C2, which result of complement would be affected a) Chemotaxis and inflammation b) Cytolysis, chemotaxis, inflammation, and opsonization c) Opsonization d) Cytolysis
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Cytolysis, chemotaxis, inflammation, and opsonization
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What complement result involves the use of phagocytes a) Cytolysis b) Opsonization c) Chemotaxis d) Chemotaxis and opsonization
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Chemotaxis and opsonization
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Which of the following statements regarding the surface of the skin is false? a) It is acidic. b) It has goblet cells. c) It has sebum as a coating. d) It has normal microbiota. e) It is salty.
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It has goblet cells
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A differential white blood cell count that shows elevated levels of eosinophils probably indicates which of the following in the patient? a) allergies b) viral infection c) cancer d) bacterial infection
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allergies
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Tears contain which of the following antibacterial substances? a) mucus b) lysozyme c) sebum d) hydrogen peroxide
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lysozyme
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The characteristic of adaptive immunity by which the adaptive immune response acts against one molecular shape and no others is called __________. a) inducibility b) memory c) specificity d) clonality
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specificity
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Antigen processing and presentation a) is a way for viruses to infect cells. b) is the way foreign cells engulf macrophages. c) is a way for a cell to give information about its activities. d) is only accomplished by bacterial cells.
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is a way for a cell to give information about its activities.
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Why would a body cell that is not a phagocyte need to present antigens? a) Antigens are infectious and can spread to normal cells. b) Non-phagocytic body cells can become infected with a virus. c) Antigens are required for cell-to-cell attachment. d) All cells of the body can engulf invading cells.
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Non-phagocytic body cells can become infected with a virus.
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How do phagocytes communicate to other cells what they have captured? a) They engulf virally infected cells. b) They spread viruses to other cells. c) They present antigens from engulfed foreign cells.
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They present antigens from engulfed foreign cells.
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Which type of cell directly attacks infected cells? a) Helper T-cells b) Cancerous cells c) Bacterial cells d) Cytotoxic T-cells
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Cytotoxic T-cells
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Cytokines are produced by which of the following cells? a) Cytotoxic T-cells b) Virally infected cells c) Invading pathogenic bacteria d) Abnormal body cells e) Helper T-cells
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Helper T-cells
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HIV directly infects T-cells. Why is this problematic for cell-mediated immunity? a) HIV reprograms these cells to attack the body cells. b) Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body. c) HIV causes cytokines to be produced at much higher levels, altering the normal function of the immune system. d) HIV transforms the T-cells into cancer cells.
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Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body.
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How do helper T-cells and cytotoxic T-cells work together? a) Cytotoxic T-cells attack abnormal body cells, while helper T-cells attack virally infected cells. b) Cytotoxic T-cells produce cytokines to activate helper T-cells. c) Helper T-cells produce cytokines to activate other cells of the immune system. d) Helper T-cells produce cytotoxic T-cells.
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Helper T-cells produce cytokines to activate other cells of the immune system.
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Mucous membranes are a part of a) cell-mediated immunity. b) humoral immunity. c) innate defense. d) the complement system. e) adaptive defense
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innate defense.
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B cells interact directly with a) helper T cells. b) phagocytes. c) the complement system. d) inflammation.
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helper T cells.
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Which of the following defense systems would be involved in fighting a viral pathogen? a) T lymphocytes b) Humoral immunity c) Complement system d) Phagocytosis
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T lymphocytes
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antibodies interact with which innate defenses? a) The complement system b) Phagocytosis and the complement system c) Phagocytosis d) Phagocytosis, inflammation, and the complement system e) Inflammation f) First-line defenses
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Phagocytosis and the complement system
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Which cells directly attack abnormal cells in the body? a) Cytotoxic T cells b) Phagocytes c) B cells d) Helper T cells
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Cytotoxic T cells
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Are Clostridium botulinum vegetative cells required to be present for foodborne botulism to occur? a) No, foodborne botulism is caused by the botulinum toxin produced by the bacteria, not the bacteria themselves. b) Yes, the foodborne botulism is caused by endotoxic shock, which occurs when the cell walls of Clostridium botulinum are disrupted. c) Yes, the foodborne botulism can only be caused by infection with Clostridium botulinum vegetative cells. d) No, foodborne botulism is caused by the endospore form of Clostridium botulinum, not vegetative cells.
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No, foodborne botulism is caused by the botulinum toxin produced by the bacteria, not the bacteria themselves.
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In which of the following cases would you suspect wound botulism? A person injures herself while gardening. Four days later she begins to feel weak and dizzy, with blurred vision and progressive paralysis. A person injures herself by stepping on a rusty garden tool while gardening. Within a week, her jaw and neck muscles begin to tighen and she begins to sweat profusely. A person injures herself in a minor car accident. Within two days she develops redness, swelling, and pus at the injury site. A person injures herself with a sharp knife while cutting vegetables for dinner. Her wound becomes inflamed and warm to the touch and about four days later she develops a fever and chills.
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A person injures herself while gardening. Four days later she begins to feel weak and dizzy, with blurred vision and progressive paralysis.
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Which practice would NOT be a good way to prevent foodborne botulism? Storing canned foods in the refrigerator. Storing canned foods at room temperature. Maintaining an acidic environment below ph 4.5. Heat canned foods to at least 80 degrees Celsius for 20 minutes before consuming.
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Storing canned foods at room temperature.
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Analysis of the second swab has confirmed that the causative organism is Streptococcus pyogenes, a gram-positive organism. Imagine that you are the technician looking at the Gram stain from Shelly's culture. What would you expect to see as you look through the microscope? purple, spherical-shaped organisms arranged in chainlike formations purple, spherical-shaped organisms arranged in grapelike clusters pink, spherical-shaped organisms arranged in chainlike formations pink, rod-shaped organisms arranged in pairs
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purple, spherical-shaped organisms arranged in chainlike formations
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How will the prescribed penicillin kill S. pyogenes that is causing Shelly's infection? Penicillin will interfere with peptidoglycan synthesis, ultimately weakening the cell wall and leading to cellular lysis. Penicillin will poke holes in the plasma membrane, weakening the cell and leading to cellular lysis. Penicillin will attach to bacterial ribosomes and inhibit protein synthesis, which will lead to the death of S. pyogenes. Penicillin will disrupt the outer membrane, leading to a loss of structural integrity and death of S. pyogenes.
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Penicillin will interfere with peptidoglycan synthesis, ultimately weakening the cell wall and leading to cellular lysis
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What effect will the penicillin have on Shelly's cells? The penicillin will not have any impact on Shelly's cells because it targets peptidoglycan, which is found only in bacteria. The penicillin will also kill some of Shelly's cells by disrupting the structure of the plasma membrane. The penicillin will kill some of Shelly's cells because it targets the ribosomes, a structure found in both prokaryotes and eukaryotes. There will be no impact on Shelly's cells because penicillin targets the flagella, which are found only in bacteria.
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The penicillin will not have any impact on Shelly's cells because it targets peptidoglycan, which is found only in bacteria.
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What is the best way to prevent nosocomial MRSA infections? People should be vaccinated with the MRSA vaccine. Everyone should wash their hands before eating and after contact with any potentially contaminated surface/person. All hospitalized patients should take antibiotics daily. All hospitalized patients should wear a surgical mask
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Everyone should wash their hands before eating and after contact with any potentially contaminated surface/person.
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What is empyema? Septicemia refers to a pocket of pus in between the lung and the inner surface of the chest wall. Empyema refers to a pocket of pus in between the lung and the inner surface of the chest wall. Empyema refers to blood in the pleural cavity. Empyema refers to air in the pleural cavity.
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Empyema refers to a pocket of pus in between the lung and the inner surface of the chest wall.
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How does β-lactamase contribute to the virulence of Staphylococcus spp.? β-lactamase breaks down penicillin and cephalosporin. β-lactamase breaks down hyaluronic acid in the matrix between cells. β-lactamase destroys neutrophils. β-lactamase triggers blood clot formation.
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β-lactamase breaks down penicillin and cephalosporin.
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Which of the following lists the criteria for a diagnosis of Staphylococcus aureus infection? Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive bacilli. Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive cocci. Staphylococcus aureus cultures are coagulase positive, catalase negative, translucent colonies that are composed of Gram-positive cocci. Staphylococcus aureus cultures are coagulase negative, catalase positive, white colonies that are composed of Gram-positive cocci.
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Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive cocci.
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A patient has a positive tuberculin skin test. Without any other information about the patient, which of the following is the most accurate interpretation of this result? The patient is able to transmit M. tuberculosis to other individuals. The patient has disseminated tuberculosis. The patient has been exposed to M. tuberculosis. The patient has primary tuberculosis.
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The patient has been exposed to M. tuberculosis.
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Which of the following statements about Bacillus anthracis is FALSE? It is primarily a disease of humans. It has a capsule. It can be lethal even after treatment because antimicrobial drugs do not inactivate accumulated anthrax toxin. It produces endospores. It normally dwells in the soil and can survive in the environment for centuries or longer.
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It is primarily a disease of humans.
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Which of the following bacteria can cause life-threatening pseudomembranous colitis? Staphylococcus aureus Clostridium difficile Enterococcus species Clostridium botulinum Streptococcus pyogenes
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Clostridium difficile
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Which of the following forms of anthrax is transmitted by the endospores of Bacillus anthracis? cutaneous and inhalation inhalation and gastrointestinal cutaneous only cutaneous, gastrointestinal, and inhalation
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cutaneous, gastrointestinal, and inhalation
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Gonorrhea is usually a sexually transmitted disease caused by the organism Neisseria gonorrhoeae. Which of the following statements regarding the transmission of Neisseria gonorrhoeae is FALSE? Neisseria gonorrhoeae can be transmitted via direct contact during sexual intercourse. Neisseria gonorrhoeae is commonly transmitted through the sharing of needles during drug use or by contaminated blood products. Neisseria gonorrhoeae can be transmitted to a child by direct contact by an infected mother during birth. Neisseria gonorrhoeae can be transmitted through autoinoculation from the reproductive tract to the rectum.
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Neisseria gonorrhoeae is commonly transmitted through the sharing of needles during drug use or by contaminated blood products.
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_________ are the primary means by which Neisseria gonorrhoeae attaches to the mucous membranes of the reproductive tract. Flagella Endotoxins Capsules Fimbriae
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Fimbriae
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Who do you think would be more likely NOT to recognize the symptoms of gonorrhea: a man or a woman? Why? Because men normally have discharge from the penis on a regular basis, a man may not recognize this as abnormal and fail to seek treatment. Because of her particular anatomy, the normal discharge associated with the female reproductive tract, plus the fact that more women are asymptomatic for gonorrhea, a woman would be less likely to recognize the symptoms as being gonorrhea and seek treatment. Because of a woman's anatomy, it is harder for her to contract gonorrhea from a man, so she would be less likely to suspect it as a cause for her symptoms. Because males most often have pain with urination as one of their main symptoms, they could confuse these symptoms with those of a urinary tract infection rather than gonorrhea.
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Because of her particular anatomy, the normal discharge associated with the female reproductive tract, plus the fact that more women are asymptomatic for gonorrhea, a woman would be less likely to recognize the symptoms as being gonorrhea and seek treatment.
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Even though Escherichia coli can cause, on occasion, severe human disease, there is no vaccine developed for it. Why do you think this is? There is no vaccine developed for Escherichia coli because it is an advantageous part of our normal intestinal flora. There is no vaccine developed for Escherichia coli because there are not very many antigenic determinants on the surface of the cell that are suitable for making antibodies. There is no vaccine developed for Escherichia coli because there are simply too many strains to make an effective vaccine that would eliminate it. There is no vaccine developed for Escherichia coli because there is a capsule that coats the surface of the cell, hiding the antigens from the immune system.
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There is no vaccine developed for Escherichia coli because it is an advantageous part of our normal intestinal flora.
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A man comes to the clinic with an oozing wound he got while preparing dinner. The doctors at the clinic suspect infection with E. coli and treat him with an antibiotic. The man goes home and his symptoms improve, so he discontinues the antibiotic. Within a few days he becomes gravely ill with shocklike symptoms such as fever, hypotension, high heart rate and fatigue/mental confusion. Why did the man become so sick after taking the antibiotic that was supposed to make him better? The man discontinued his antibiotic and the infection rebounded, causing his symptoms. The initial E. coli infection was resistant to the antibiotic and the man became more ill. The antibiotic given to the man and the man's own immune response caused the lysis of the E. coli cells and release of endotoxin (LPS). This caused his secondary symptoms of endotoxic shock. The man developed a secondary infection due to his weakened immune system from fighting the first infection.
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The antibiotic given to the man and the man's own immune response caused the lysis of the E. coli cells and release of endotoxin (LPS). This caused his secondary symptoms of endotoxic shock.
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Over 90% of urinary tract infections (UTIs) are caused by Escherichia coli strains. UTIs are 14 times more common in women than in men. Why do you think this is? UTIs caused by E. coli are 14 times more common in women than in men because E. coli does not adhere to the man's urethra as well as the woman's. UTIs caused by E. coli are 14 times more common in women than in men because the pH of a woman's urinary tract is more favorable for the growth of E. coli. UTIs caused by E. coli are 14 times more common in women than in men because women have a shorter urethra than men and the proximity of the urethra to the anus is much closer in women. UTIs caused by E. coli are 14 times more common in women than in men because the temperature of urine in men is less than body temperature, which is less favorable for the growth of E. coli.
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UTIs caused by E. coli are 14 times more common in women than in men because women have a shorter urethra than men and the proximity of the urethra to the anus is much closer in women.
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Of the pathogenic forms of Escherichia coli, the strain O157:H7 is the primary cause of hemorrhagic colitis, or bloody diarrhea, and can progress to the often fatal hemolytic uremic syndrome (HUS). What is the main reason for the severity of illness from this strain of E. coli? The main reason for the severity of illness comes from the ability of this particular strain of E. coli to produce Shiga-like toxin, which causes an intense inflammatory response in the gut. The main reason for the severity of illness comes from the ability of this particular strain of E. coli to hide from the host immune system. The main reason for the severity of illness comes from the ability of this particular strain of E. coli to kill off the nonpathogenic strains of E. coli and colonize the host. The main reason for the severity of illness comes from the ability of this particular strain of E. coli to adhere very tightly to the cells lining the gut, which allows it to multiply rapidly.
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The main reason for the severity of illness comes from the ability of this particular strain of E. coli to produce Shiga-like toxin, which causes an intense inflammatory response in the gut.
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Which of the following is NOT a virulence factor for Helicobacter pylori? adhesins that help H. pylori to attach to gastric cells flagella that help H. pylori to burrow through the mucus lining the production of urease, which neutralizes stomach acid the ability of H. pylori to enter cells for protection
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the ability of H. pylori to enter cells for protection
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Until very recently, it was thought that peptic ulcers were caused by stress, spicy foods, alcohol consumption, and excess stomach acid production. Why was it controversial to suggest that a bacterium could be a root cause for peptic ulcers? Because scientists thought that excess acid could cause the erosion of the stomach lining, it followed that production of excess acid caused ulcers. Until recently, scientists did not believe that bacteria could survive and reproduce in the harsh, acidic environment of the stomach. Because people who consume excess amounts of alcohol and often eat spicy foods tend to develop ulcers, it was thought that these were the cause. Because people living in stressful situations often develop ulcers, scientists thought that stress was the most likely cause for this condition.
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Until recently, scientists did not believe that bacteria could survive and reproduce in the harsh, acidic environment of the stomach.
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Helicobacter pylori can survive in the acidic environment of the stomach but is actually considered to be a neutrophile. How can this be? Helicobacter pylori can survive in the acidic environment of the stomach because even though it prefers a neutral environment, it can tolerate an acidic one. Helicobacter pylori can survive in the acidic environment of the stomach because it is a spore former and the spores can survive the acid environment. Helicobacter pylori can survive in the acidic environment of the stomach because it can neutralize the pH in the local area of infection. Helicobacter pylori can survive in the acidic environment of the stomach because it neutralizes the pH of the entire stomach upon infection.
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Helicobacter pylori can survive in the acidic environment of the stomach because it can neutralize the pH in the local area of infection.
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How are viruses different from cells? They do not contain genetic material. They require a host in order to reproduce. They do not contain enzymes. They do not contain protein.
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They require a host in order to reproduce
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What is the function of the structural elements of a virus? To provide a source of energy for the virus To use all of the cell proteins To package and protect the viral genome
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To package and protect the viral genome
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Contact between a phage and its bacterial host occurs by _____. a random collision using flagella using jet-style propulsion using phage tail fibers
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a random collision
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What portion of bacteriophage T4 enters E. coli? No portion of phage T4 actually enters the bacterial cell. The entire phage enters into the bacterial cell. Only the tail fibers penetrate into the interior of the bacterial cell. Only the T4 genome enters the bacterial cell.
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Only the T4 genome enters the bacterial cell.
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Once entry into the bacterial cell has been achieved, the next step in a lytic replication cycle is _____. assembly attachment release synthesis
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synthesis
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During a lytic replication cycle, what action does a phage take to ensure that its host bacterium does NOT continue synthesizing cellular molecules? A phage traps the host DNA in an endosome. The phage integrates its DNA into the host cell DNA. Phage enzymes degrade the bacterial DNA. The host DNA is released from the cell.
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Phage enzymes degrade the bacterial DNA.
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In a lytic cycle of replication, release of phages involves _____. the bacterial cell bursting open exocytosis of phages across the cell wall keeping the host cell alive contact with another uninfected bacterium
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the bacterial cell bursting open
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A major difference between the lytic and lysogenic cycles of phage replication is that during the lysogenic phase _____. the bacterial cell is broken open, destroying the cell the phage genome inserts itself into the host genome the host DNA is degraded attachment of the phage involves a random collision
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the phage genome inserts itself into the host genome
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What factor may induce a prophage to enter the lytic cycle? UV light Infection by an additional phage burst time replication of the host bacterium
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UV light
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During the lysogenic cycle, it is possible for integrated phage genes to change the characteristics of the host cell. This is known as _____. lysogenic conversion synthesis induction transduction
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lysogenic conversion
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Which nucleic acid is part of the varicella-zoster virion? dsDNA ssDNA ssRNA dsRNA
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dsDNA
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What causes warts? herpes virus handling frogs and toads Epstein-Barr virus papillomavirus
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papillomavirus
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Is it possible for Rudy's warts to spread to other areas of his body? No. You have to handle frogs to get or spread warts. Yes, especially if he undergoes laser treatments. No. The virus is inactivated below 35 degrees Celsius. Yes. Papillomaviruses are spread by direct contact.
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Yes. Papillomaviruses are spread by direct contact.
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What type of cancer is more likely to develop in people who have had papillomavirus infections? colon cancer leukemia lung cancer cancer of the tonsils
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cancer of the tonsils
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Which of the following is NOT an accepted treatment for warts? daily application of salicylic acid daily application of tincture of iodine to the wart surface "freezing" the wart with liquid nitrogen covering the wart with a piece of duct tape for several weeks
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daily application of tincture of iodine to the wart surface
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Reactivation of ________ in immunosuppressed persons may produce Kaposi's sarcoma, a cancer of the blood vessels. HHV-6 HHV-8 cytomegalovirus EBV BK virus
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HHV-8
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Human herpesvirus 4 (EBV) is implicated in which of the following diseases? oral hairy leukoplakia Burkitt's lymphoma cervical cancer chronic fatigue syndrome Burkitt's lymphoma, chronic fatigue syndrome, and oral hairy leukoplakia
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Burkitt's lymphoma, chronic fatigue syndrome, and oral hairy leukoplakia
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Which of the following families of DNA viruses is the most prevalent in humans? Poxviridae Polyomaviridae Adenoviridae Herpesviridae Rhinoviridae
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Herpesviridae
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What organism causes thrush? Streptococcus mutans Candida albicans Saccharomyces cerevisiae Escherichia coli
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Candida albicans
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Pneumocystis pneumonia is caused by an opportunistic __________. virus protozoan fungus bacterium
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fungus
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Many of the most severe strains of influenza A have originated in Asia. Asia is a major originator of pandemic strains and a major site of antigenic shift. Which of the following reasons could be a cause of this? Water sanitation in most Asian countries is not as standardized as it is in other countries. In Asia, the population density of humans, domesticated birds, and pigs is very high. Individuals in Asia are more susceptible to influenza than individuals on other continents. Most Asian countries do not have large-scale vaccination programs for influenza.
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In Asia, the population density of humans, domesticated birds, and pigs is very high.
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Why is it important to get a new flu vaccine every year? Every season, the hemagglutinin and neuraminidase proteins on the viral envelope of influenza are subject to slight changes by mutation, allowing evasion of the immune system. The immune system fails to generate memory B cells when inoculated with this vaccine. Thus, the immune system can't "remember" the influenzavirus. Antigenic shift creates completely new surface proteins every year, allowing for evasion of the immune system. The immunity provided by the flu vaccine lasts only through the flu season.
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Every season, the hemagglutinin and neuraminidase proteins on the viral envelope of influenza are subject to slight changes by mutation, allowing evasion of the immune system.
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The devastating 1918 influenza pandemic killed an estimated 50 million people during the 1918-19 flu season. Unusually, young people between the ages of 15-24 were greatly impacted. It is believed that a robust immune response to this particular virus caused its virulence. Which of the following immune responses is likely to have caused these devastating consequences? antibodies produced by B cells recruitment of an excess of eosinophils an exaggerated complement activation high cytokine concentrations
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high cytokine concentrations
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The antiviral drug oseltamivir (Tamiflu) blocks the release of the virus from infected cells and must be given within 24-48 hours of infection to be effective against the duration of the flu symptoms. Based on how the influenzavirus manifests signs and symptoms, why is the 24-48 hour window important? The signs and symptoms of the flu are caused by the activation of B cells and the antibody response. After 48 hours, this response has already been sufficiently triggered. The signs and symptoms of the flu are caused by the release of cytokines from the host immune system. After 48 hours, this response has already been sufficiently triggered. After 48 hours, so many virions have been released that the drug has no effect. After 48 hours, the virus particles are no longer susceptible to the drug and it has no effect.
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The signs and symptoms of the flu are caused by the release of cytokines from the host immune system. After 48 hours, this response has already been sufficiently triggered.
