30 Questions
What is the primary function of exterior defences in non-specific host defence?
To provide a physical and biochemical barrier against infectious agents
Which of the following is NOT a function of phagocytes?
Releasing antibodies into the bloodstream
What is the role of interferons in the innate immune response?
To inhibit viral replication and induce an antiviral state
Which of the following is an example of antibody-mediated immunity?
Antibodies neutralizing toxins produced by bacteria
What is the primary function of complement proteins in the innate immune response?
To mark pathogens for destruction by phagocytic cells
Which of the following is an example of cell-mediated immunity?
T-cells recognizing and killing infected cells
What happens when virally infected cells release interferons?
Signal neighbouring cells to produce antiviral proteins
Which pathway is involved in the activation of complement proteins that bind directly to bacteria?
Alternate pathway
What is the process by which antibodies facilitate the engulfment of bacteria by phagocytic cells?
Opsonisation
What is the primary function of antibodies in antibody-mediated immunity?
Directly bind to and neutralise a pathogen
Which cells are responsible for displaying viral fragments on their surface via MHC I?
Infected cells
What is the result of the membrane attack complex (MAC) formation in complement-mediated lysis?
Insertion into the membrane and facilitates osmotic lysis
What is the primary function of phagocytes in the immune system?
To recognize and engulf foreign microorganisms
Which of the following is NOT a type of phagocyte?
Lymphocytes
What is the process by which phagocytes are attracted to microorganisms?
Chemotaxis
What is the name of the vesicle that forms when phagosomes fuse with lysosomes?
Phagolysosome
Which type of granulocyte predominates in the initial phase of infection?
Neutrophils
What is the function of lysozyme in phagocytosis?
To destroy microorganisms
What is the primary mechanism of Natural Killer cells in destroying infected cells?
By releasing enzymes that induce apoptosis in infected cells
What is the role of interferons in the immune response?
To activate Natural Killer cells and macrophages
What is the result of antibody-antigen binding?
All of the above
What is the primary function of the adaptive immune system?
To produce antibodies against specific pathogens
What is the role of an antibody in activating the classical pathway of complement?
It activates the classical pathway
What is the end result of the activation of the adaptive immune system?
Recovery and immunologic memory
What is the result of capsule production by some bacteria?
It prevents phagocytosis
What is the function of leukocidins produced by some bacteria?
They kill white blood cells
What is the primary function of macrophages in the immune response?
To phagocytose infected cells and foreign particles
What is the outcome of acquired immunity?
No disease results upon re-infection
What is the difference between exotoxins and endotoxins?
Exotoxins are produced by Gram-positive bacteria, while endotoxins are produced by Gram-negative bacteria
What is the purpose of toxoids?
To stimulate the production of antitoxins and provide immunity
Learn about the complexities of host-pathogen interactions, including non-specific and specific host defenses, and pathogenic mechanisms. Understand the different types of acquired immunity and the role of innate immunity. This quiz covers the key concepts in microbiology and infectious diseases.
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