Question 1

Which of the following best describes the main difference between the innate and adaptive immune systems?

Accepted Answer

The innate immune system recognizes general patterns, while the adaptive immune system recognizes specific molecular structures.

Question 2

Which of the following is NOT a physical barrier provided by the innate immune system?

Accepted Answer

Sebum

Question 3

A patient is infected with a Gram-negative bacterium. Which Toll-like receptor (TLR) is most likely to recognize a component of this pathogen?

Accepted Answer

TLR4

Question 4

Which of the following best explains why the innate immune response is considered 'non-specific'?

Accepted Answer

It uses pattern recognition receptors to detect common features of pathogens, not unique antigens.

Question 5

Which of the following is a function of the complement system in innate immunity?

Accepted Answer

Forming the membrane attack complex (MAC) to lyse microbial cells.

Question 6

Which of the following best describes the role of phagocytic cells in the innate immune response?

Accepted Answer

They ingest and destroy microbes through phagocytosis and respiratory burst.

Question 7

Which of the following is a Pathogen-Associated Molecular Pattern (PAMP) recognized by Toll-like receptors?

Accepted Answer

Bacterial flagellin

Question 8

A mutation in the gene encoding TLR5 would most likely impair the immune system’s ability to detect which microbial structure?

Accepted Answer

Flagellin

Question 9

Which of the following events is NOT a typical feature of inflammation?

Accepted Answer

Decreased recruitment of white blood cells

Question 10

Which of the following best describes the function of chemokines in the innate immune response?

Accepted Answer

They control the localization and recruitment of immune cells to sites of infection.

Question 11

Which of the following is a correct sequence of events in the innate immune response?

Accepted Answer

Recognition → Alarm → Inflammation → Recruitment → Effector Function

Question 12

Which of the following is a characteristic of the adaptive immune system but NOT the innate immune system?

Accepted Answer

Recognition of specific 3-D structures or protein sequences

Question 13

Which of the following best explains why normal flora (microbiota) are considered a biological barrier in innate immunity?

Accepted Answer

They compete with pathogens for nutrients and attachment sites, limiting pathogen colonization.

Question 14

Which of the following is a correct description of the classical pathway of complement activation?

Accepted Answer

It is initiated by antibody binding to a microbe, leading to a cascade of complement activation.

Question 15

Which of the following best describes the role of dendritic cells in the immune system?

Accepted Answer

They are professional antigen-presenting cells that bridge innate and adaptive immunity.

Question 16

A patient with a deficiency in neutrophils would most likely have difficulty with which of the following?

Accepted Answer

Phagocytizing bacteria and forming pus at infection sites

Question 17

Which of the following is a chemical barrier that contributes to the first line of defense?

Accepted Answer

Lysozyme in tears and saliva

Question 18

Which of the following best describes the function of Natural Killer (NK) cells in innate immunity?

Accepted Answer

They kill virus-infected or cancerous cells by recognizing changes in surface molecules.

Question 19

Which of the following is a correct statement about the lymphatic system?

Accepted Answer

It drains excess fluid and proteins from tissues and provides sites for immune cell interactions.

Question 20

Which of the following best explains why the response of the innate immune system does not improve upon repeated exposure to the same pathogen?

Accepted Answer

Innate immunity does not generate immunological memory.

Innate Immune System: Structure, Function, and Response

Study Guide - Practice Questions