WK 6: Host-Pathogen Interactions Microbiology

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What is the primary function of exterior defences in non-specific host defence?

To provide a physical and biochemical barrier against infectious agents (correct)

To recognize and respond to specific pathogens

To produce antibodies against pathogens

To activate the adaptive immune response

Which of the following is NOT a function of phagocytes?

Producing interferons to combat viral infections

Engulfing and digesting foreign particles and microorganisms

Releasing antibodies into the bloodstream (correct)

Presenting antigens to T-cells

What is the role of interferons in the innate immune response?

To produce antibodies against viruses

To directly kill infected cells

To inhibit viral replication and induce an antiviral state (correct)

To activate the adaptive immune response

Which of the following is an example of antibody-mediated immunity?

Antibodies neutralizing toxins produced by bacteria (B) Signup and view all the answers

What is the primary function of complement proteins in the innate immune response?

To mark pathogens for destruction by phagocytic cells (D) Signup and view all the answers

Which of the following is an example of cell-mediated immunity?

T-cells recognizing and killing infected cells (D) Signup and view all the answers

What happens when virally infected cells release interferons?

Signal neighbouring cells to produce antiviral proteins (B) Signup and view all the answers

Which pathway is involved in the activation of complement proteins that bind directly to bacteria?

Alternate pathway (B) Signup and view all the answers

What is the process by which antibodies facilitate the engulfment of bacteria by phagocytic cells?

Opsonisation (C) Signup and view all the answers

What is the primary function of antibodies in antibody-mediated immunity?

Directly bind to and neutralise a pathogen (B) Signup and view all the answers

Which cells are responsible for displaying viral fragments on their surface via MHC I?

Infected cells (D) Signup and view all the answers

What is the result of the membrane attack complex (MAC) formation in complement-mediated lysis?

Insertion into the membrane and facilitates osmotic lysis (B) Signup and view all the answers

What is the primary function of phagocytes in the immune system?

To recognize and engulf foreign microorganisms (A) Signup and view all the answers

Which of the following is NOT a type of phagocyte?

Lymphocytes (A) Signup and view all the answers

What is the process by which phagocytes are attracted to microorganisms?

Chemotaxis (C) Signup and view all the answers

What is the name of the vesicle that forms when phagosomes fuse with lysosomes?

Phagolysosome (D) Signup and view all the answers

Which type of granulocyte predominates in the initial phase of infection?

Neutrophils (A) Signup and view all the answers

What is the function of lysozyme in phagocytosis?

To destroy microorganisms (C) Signup and view all the answers

What is the primary mechanism of Natural Killer cells in destroying infected cells?

By releasing enzymes that induce apoptosis in infected cells (C) Signup and view all the answers

What is the role of interferons in the immune response?

To activate Natural Killer cells and macrophages (C) Signup and view all the answers

What is the result of antibody-antigen binding?

All of the above (D) Signup and view all the answers

What is the primary function of the adaptive immune system?

To produce antibodies against specific pathogens (A) Signup and view all the answers

What is the role of an antibody in activating the classical pathway of complement?

It activates the classical pathway (A) Signup and view all the answers

What is the end result of the activation of the adaptive immune system?

Recovery and immunologic memory (C) Signup and view all the answers

What is the result of capsule production by some bacteria?

It prevents phagocytosis (D) Signup and view all the answers

What is the function of leukocidins produced by some bacteria?

They kill white blood cells (D) Signup and view all the answers

What is the primary function of macrophages in the immune response?

To phagocytose infected cells and foreign particles (B) Signup and view all the answers

What is the outcome of acquired immunity?

No disease results upon re-infection (B) Signup and view all the answers

What is the difference between exotoxins and endotoxins?

Exotoxins are produced by Gram-positive bacteria, while endotoxins are produced by Gram-negative bacteria (A) Signup and view all the answers

What is the purpose of toxoids?

To stimulate the production of antitoxins and provide immunity (B) Signup and view all the answers