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 the pathogen-associated molecular pattern (PAMP) on this bacterium?

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

A mutation causes a loss of function in TLR5. Which type of pathogen recognition would be most affected?

Accepted Answer

Recognition of bacterial flagellin

Question 8

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

Accepted Answer

Lysozyme in tears and saliva

Question 9

Which event occurs earliest in the innate immune response to a bacterial infection?

Accepted Answer

Recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs)

Question 10

Which of the following best describes the function of cytokines during the innate immune response?

Accepted Answer

They control immune cell activation and coordinate the inflammatory response.

Question 11

A patient with a genetic deficiency in complement protein C3 would most likely have which of the following problems?

Accepted Answer

Impaired ability to lyse bacteria and recruit phagocytes

Question 12

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

Accepted Answer

Recognition → Alarm → Inflammation → Recruitment → Effector Function

Question 13

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

Accepted Answer

Recognition of specific 3-D structures or protein sequences

Question 14

Which of the following best explains why normal flora are considered a biological barrier?

Accepted Answer

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

Question 15

Which of the following is a function of Natural Killer (NK) cells in the innate immune system?

Accepted Answer

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

Question 16

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

Accepted Answer

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

Question 17

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

Accepted Answer

It is initiated by antibody binding to antigens on the pathogen surface.

Question 18

Which of the following is a characteristic sign of inflammation?

Accepted Answer

Heat, pain, redness, and swelling

Question 19

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

Accepted Answer

The innate immune system does not generate immunological memory.

Question 20

Which of the following is a direct result of the activation of pattern recognition receptors (PRRs) on innate immune cells?

Accepted Answer

Activation of immune cells and initiation of inflammatory responses

Innate Immune System: Structure, Function, and Mechanisms

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