Microbiology Multiple Choice Questions PDF

## Multiple-Choice Questions ### 1. Outline the Relationship Between Microbes And Their Host **Question:** Which of the following best describes the relationship between microbes and their host? - Microbes always cause disease in the host. - Microbes and hosts have a symbiotic relationship where bot...

## Multiple-Choice Questions ### 1. Outline the Relationship Between Microbes And Their Host **Question:** Which of the following best describes the relationship between microbes and their host? - Microbes always cause disease in the host. - Microbes and hosts have a symbiotic relationship where both benefit. - Microbes are always harmful and must be eliminated. - Microbes can be beneficial or harmful depending on the context. ### 2. Outline Components of the Chain of Infection **Question:** Which of the following is NOT a component of the chain of infection? - Source of infection - Mode of transmission - Susceptible host - Antibiotic resistance ### 3. Categorize Human Microbiota **Question:** Which of the following is a characteristic of resident microbiota? - Found temporarily on and in the body sites. - Routinely found on and in the body sites. - Always pathogenic. - Only found in the gut. ### 4. Explain the Role of Microbiome in Health and Disease **Question:** Which of the following is a role of the microbiome in health? - Synthesize several of the B vitamins and vitamin K. - Increase the risk of infections. - Cause autoimmune diseases. - Suppress the immune system. ### 5. List The Factors Determining Host-Microbe Relationship **Question:** Which of the following is a microbial factor that determines the host-microbe relationship? - Innate immunity. - The number of organisms. - Acquired immunity. - Phagocytosis. ### 6. Recognize Bacterial Virulence Factors **Question:** Which of the following is a virulence factor that helps bacteria adhere to host cells? - Collagenase. - Hyaluronidase. - Pili. - Leukocidin. ### 7. Compare Exotoxins and Endotoxins **Question:** Which of the following statements is true regarding exotoxins? - Composed of lipopolysaccharides. - Stable at 100°C for one hour. - Poorly antigenic. - Can be converted to toxoids. ### 8. Modes of Transmission of Infection **Question:** Which mode of transmission involves the transfer of infectious material from a vector to the host? - Direct contact. - Indirect contact. - Vector-borne transmission. - Airborne transmission. ### 9. Horizontal Transmission **Question:** What type of horizontal transmission occurs when large droplets containing microorganisms are generated from infected persons during sneezing, coughing, or talking? - Direct contact. - Indirect contact. - Droplet transmission. - Airborne transmission. ### 10. Vertical Transmission **Question:** Which of the following is an example of vertical transmission? - From one person to another. - From mother to offspring. - Through contaminated food. - By insect bites. ### 11. Resident Microbiota **Question:** Where are resident microbiota typically found? - Temporarily on and in the body sites. - Routinely on and in the body sites. - Only in the gut. - Only on the skin. ### 12. Transient Microbiota **Question:** Which of the following best describes transient microbiota? - Microbial populations routinely found on and in the body sites. - Microbial populations found temporarily on and in the body sites. - Always pathogenic. - Only found in the gut. ### 13. Role of Microbiome in Immune System Development **Question:** How does the microbiome contribute to the immune system in newborns? - By suppressing the immune response. - By increasing the risk of infections. - By acting as a powerful stimulus for the developing immune system. - By causing autoimmune diseases. ### 14. Limiting Pathogen Growth **Question:** How do resident microbiota limit the growth of pathogens? - By occupying attachment sites on the mucosa. - By increasing the pH of the environment. - By producing antibiotics. - By enhancing the host's immune response. ### 15. Nutritional Contribution of Microbiome **Question:** Which of the following is a nutritional contribution of the microbiome? - Synthesizing several of the B vitamins and vitamin K. - Increasing the risk of nutrient deficiencies. - Causing malabsorption syndromes. - Reducing the absorption of minerals. ### 16. Pathogenicity of Microbiome **Question:** Under what conditions can the microbiome cause disease? - In healthy individuals. - In immunocompromised individuals. - When the composition of normal flora is stable. - When the microbiome is absent. ### 17. Host Factors In Host-Microbe Relationship **Question:** Which of the following is a host factor that influences the host-microbe relationship? - The number of organisms. - The virulence factors. - Innate and acquired immunity. - The presence of a capsule. ### 18. Virulence Factors: Adherence **Question:** Which of the following is a virulence factor that enables bacteria to adhere to host cell surfaces? - Collagenase. - Hyaluronidase. - Pili. - Leukocidin. ### 19. Virulence Factors: Invasion **Question:** Which enzyme helps bacteria invade host tissues by degrading collagen and hyaluronic acid? - Collagenase. - Hyaluronidase. - Lecithinase. - Leukocidin. ### 20. Virulence Factors: Iron Competition **Question:** How do bacteria compete for iron in the host? - By producing antibodies. - By using siderophores. - By producing toxins. - By increasing the pH of the environment. ### 21. Virulence Factors: Limiting Host Defense **Question:** Which of the following is a virulence factor that prevents phagocytes from adhering to bacteria? - Pili. - Adhesins. - Capsule. - Leukocidin. ### 22. Intracellular Survival **Question:** Why do some bacteria survive intracellularly? - To avoid detection by the immune system. - To avoid being eaten by phagocytes. - To produce more toxins. - To increase their virulence. ### 23. Virulence Factors: Toxin Production **Question:** Which of the following is a type of bacterial toxin? - Collagenase. - Hyaluronidase. - Exotoxin. - Leukocidin. ### 24. Exotoxins **Question:** Which of the following is a characteristic of exotoxins? - Composed of lipopolysaccharides. - Stable at 100°C for one hour. - Poorly antigenic. - Can be converted to toxoids. ### 25. Endotoxins **Question:** Which of the following is a characteristic of endotoxins? - Composed of proteins. - Can be converted to toxoids. - Composed of lipopolysaccharides. - Highly antigenic. ### 26. Horizontal Transmission: Contact **Question:** What is an example of direct contact transmission? - Touching a contaminated surface. - Sneezing. - Physical touch between two people. - Eating contaminated food. ### 27. Horizontal Transmission: Inhalation **Question:** What is an example of airborne transmission? - Touching a contaminated surface. - Sneezing. - Physical touch between two people. - Breathing in droplet nuclei. ### 28. Horizontal Transmission: Vehicle **Question:** What is an example of vehicle transmission? - Touching a contaminated surface. - Sneezing. - Physical touch between two people. - Drinking contaminated water. ### 29. Horizontal Transmission: Vector-Borne **Question:** What is an example of vector-borne transmission? - Touching a contaminated surface. - Sneezing. - Physical touch between two people. - Mosquito bite. ### 30. Resident Microbiota: Examples **Question:** Which of the following is an example of a site where resident microbiota can be found? - Bloodstream. - Brain. - Skin. - Heart. ### 31. Transient Microbiota: Examples **Question:** Which of the following is an example of a site where transient microbiota can be found? - Gut. - Skin. - Mouth. - All of the above. ### 32. Role of Microbiome: Immune System **Question:** How does the microbiome stimulate the immune system in newborns? - By producing antibodies. - By acting as a powerful stimulus for the developing immune system. - By causing inflammation. - By suppressing immune responses. ### 33. Role of Microbiome: Pathogen Limitation **Question:** How do resident microbiota limit the growth of pathogens? - By occupying attachment sites on the mucosa. - By producing antibiotics. - By increasing the pH of the environment. - By enhancing the host's immune response. ### 34. Role of Microbiome: Nutrition **Question:** Which of the following is a nutritional benefit provided by the microbiome? - Synthesizing several of the B vitamins and vitamin K. - Causing malabsorption syndromes. - Reducing the absorption of minerals. - Increasing the risk of nutrient deficiencies. ### 35. Pathogenicity of Microbiome: Conditions **Question:** Under which condition can the microbiome become pathogenic? - In healthy individuals. - In immunocompromised individuals. - When the composition of normal flora is stable. - When the microbiome is absent. ### 36. Host Factors: Immunity **Question:** Which of the following is a host factor that influences the host-microbe relationship? - The number of organisms. - The virulence factors. - Innate and acquired immunity. - The presence of a capsule. ### 37. Virulence Factors: Adherence **Question:** Which of the following is a virulence factor that enables bacteria to adhere to host cell surfaces? - Collagenase. - Hyaluronidase. - Pili. - Leukocidin. ### 38. Virulence Factors: Invasion **Question:** Which enzyme helps bacteria invade host tissues by degrading collagen and hyaluronic acid? - Collagenase. - Hyaluronidase. - Lecithinase. - Leukocidin. ### 39. Virulence Factors: Iron Competition **Question:** How do bacteria compete for iron in the host? - By producing antibodies. - By using siderophores. - By producing toxins. - By increasing the pH of the environment. ### 40. Virulence Factors: Limiting Host Defense **Question:** Which of the following is a virulence factor that prevents phagocytes from adhering to bacteria? - Pili. - Adhesins. - Capsule. - Leukocidin. ### 41. Intracellular Survival **Question:** Why do some bacteria survive intracellularly? - To avoid detection by the immune system. - To avoid being eaten by phagocytes. - To produce more toxins. - To increase their virulence. ### 42. Virulence Factors: Toxin Production **Question:** Which of the following is a type of bacterial toxin? - Collagenase. - Hyaluronidase. - Exotoxin. - Leukocidin. ### 43. Exotoxins **Question:** Which of the following is a characteristic of exotoxins? - Composed of lipopolysaccharides. - Stable at 100°C for one hour. - Poorly antigenic. - Can be converted to toxoids. ### 44. Endotoxins **Question:** Which of the following is a characteristic of endotoxins? - Composed of proteins. - Can be converted to toxoids. - Composed of lipopolysaccharides. - Highly antigenic. ### 45. Horizontal Transmission: Contact **Question:** What is an example of indirect contact transmission? - Touching a contaminated surface. - Sneezing. - Physical touch between two people. - Eating contaminated food. ### 46. Horizontal Transmission: Inhalation **Question:** What is an example of droplet transmission? - Touching a contaminated surface. - Sneezing. - Physical touch between two people. - Breathing in droplet nuclei. ### 47. Horizontal Transmission: Vehicle **Question:** What is an example of vehicle transmission? - Touching a contaminated surface. - Sneezing. - Physical touch between two people. - Drinking contaminated water. ### 48. Horizontal Transmission: Vector-Borne **Question:** What is an example of vector-borne transmission? - Touching a contaminated surface. - Sneezing. - Physical touch between two people. - Mosquito bite. ### 49. Resident Microbiota: Examples **Question:** Which of the following is an example of a site where resident microbiota can be found? - Bloodstream. - Brain. - Skin. - Heart. ### 50. Transient Microbiota: Examples **Question:** Which of the following is an example of a site where transient microbiota can be found? - Gut. - Skin. - Mouth. - All of the above. ## Model Answers 1. Microbes can be beneficial or harmful depending on the context. 2. Antibiotic resistance 3. Routinely found on and in the body sites. 4. Synthesize several of the B vitamins and vitamin K. 5. The number of organisms. 6. Pili. 7. Can be converted to toxoids. 8. Vector-borne transmission. 9. Droplet transmission. 10. From mother to offspring. 11. Routinely on and in the body sites. 12. Microbial populations found temporarily on and in the body sites. 13. By acting as a powerful stimulus for the developing immune system. 14. By occupying attachment sites on the mucosa. 15. Synthesizing several of the B vitamins and vitamin K. 16. In immunocompromised individuals. 17. Innate and acquired immunity. 18. Pili. 19. Collagenase. 20. By using siderophores. 21. Capsule. 22. To avoid being eaten by phagocytes. 23. Exotoxin. 24. Can be converted to toxoids. 25. Composed of lipopolysaccharides. 26. Physical touch between two people. 27. Breathing in droplet nuclei. 28. Drinking contaminated water. 29. Mosquito bite. 30. Skin. 31. All of the above. 32. By acting as a powerful stimulus for the developing immune system. 33. By occupying attachment sites on the mucosa. 34. Synthesizing several of the B vitamins and vitamin K. 35. In immunocompromised individuals. 36. Innate and acquired immunity. 37. Pili. 38. Collagenase. 39. By using siderophores. 40. Capsule. 41. To avoid being eaten by phagocytes. 42. Exotoxin. 43. Can be converted to toxoids. 44. Composed of lipopolysaccharides. 45. Touching a contaminated surface. 46. Sneezing. 47. Drinking contaminated water. 48. Mosquito bite. 49. Skin. 50. All of the above.