Question 1

Which of the following best describes the role of Toll-like receptors (TLRs) in innate immunity?

Accepted Answer

TLRs recognize pathogen-associated molecular patterns (PAMPs) and trigger cytokine release.

Question 2

A patient presents with a high white blood cell (WBC) count of 15,000/μl. Which of the following is the most likely explanation for this finding?

Accepted Answer

The patient may have a bacterial infection or an autoimmune disease.

Question 3

Which physical barrier is LEAST likely to be breached by microorganisms under normal, healthy conditions?

Accepted Answer

The intact epidermis of the skin

Question 4

Which of the following is NOT a function of inflammation?

Accepted Answer

To directly produce antibodies against pathogens

Question 5

During phagocytosis, what is the primary function of opsonization?

Accepted Answer

To coat microorganisms with serum proteins, enhancing adherence to phagocytes

Question 6

Which of the following chemical factors is correctly matched with its antimicrobial action?

Accepted Answer

Lysozyme: destroys bacterial cell walls in tears and saliva

Question 7

A patient with a genetic deficiency in complement proteins is MOST likely to experience which of the following?

Accepted Answer

Increased susceptibility to infections

Question 8

Which of the following best explains why fever can be beneficial during an infection?

Accepted Answer

Fever increases the metabolic rate, enhances phagocyte activity, and slows pathogen growth.

Question 9

Which of the following is a correct sequence of events in the process of phagocytosis?

Accepted Answer

Chemotaxis → Adherence → Ingestion → Digestion

Question 10

Which of the following statements about normal microbiota is TRUE?

Accepted Answer

Normal microbiota compete with pathogens for space and nutrients, preventing overgrowth of harmful microbes.

Question 11

Which complement pathway is initiated when antibodies bind to antigens?

Accepted Answer

Classical pathway

Question 12

A patient with a severe bacterial infection develops a 'cytokine storm.' What is the most likely consequence?

Accepted Answer

Significant tissue damage, possibly leading to multiorgan dysfunction

Question 13

Which of the following is a function of the membrane attack complex (MAC) formed during complement activation?

Accepted Answer

Creates pores in microbial membranes, leading to cytolysis

Question 14

Which of the following best describes the role of interferons (IFNs) in innate immunity?

Accepted Answer

They induce nearby cells to produce antiviral proteins that inhibit viral replication.

Question 15

Which of the following is an example of microbial antagonism by normal microbiota?

Accepted Answer

Normal microbiota produce substances harmful to pathogens, preventing their colonization.

Question 16

Which of the following is a granulocyte that releases histamine and is involved in allergic responses?

Accepted Answer

Basophil

Question 17

Which of the following best explains why some bacteria produce siderophores?

Accepted Answer

To bind iron more effectively than host iron-binding proteins

Question 18

A patient is prescribed a probiotic supplement after antibiotic therapy. What is the most likely benefit of this intervention?

Accepted Answer

Probiotics help restore beneficial microbial populations, supporting innate immunity.

Question 19

Which of the following is a correct statement about the phases of inflammation?

Accepted Answer

Phagocyte migration follows vasodilation and increased vascular permeability.

Question 20

Which of the following best describes the function of antimicrobial peptides in innate immunity?

Accepted Answer

They inhibit cell wall synthesis, form pores in microbial membranes, and destroy nucleic acids.

Innate Immunity: Nonspecific Defenses of the Host (Chapter 16 Study Notes)

Study Guide - Practice Questions