Innate Immunity: A Comprehensive Guide for Medical Students

Question 1

Which of the following is NOT a component of the innate immune system?

Accepted Answer

Antibodies

Answer

Phagocytes

Answer

Inflammation

Answer

Natural killer cells

Question 2

Which of the following cells is NOT involved in phagocytosis?

Accepted Answer

Hepatocytes

Answer

Neutrophils

Answer

Macrophages

Answer

Dendritic cells

Question 3

What is the primary function of natural killer (NK) cells in innate immunity?

Accepted Answer

To eliminate virus-infected cells and tumor cells

Answer

To engulf and destroy microorganisms

Answer

To produce antibodies

Answer

To activate complement

Question 4

What is the process by which damaged or infected cells attract immune cells to the site of infection known as?

Accepted Answer

Chemotaxis

Answer

Phagocytosis

Answer

Opsonization

Answer

Complement activation

Question 5

Which of the following is NOT a function of the complement system?

Accepted Answer

To produce antibodies

Answer

To lyse bacteria

Answer

To opsonize microorganisms

Answer

To activate macrophages

Question 6

What is the name of the protein that binds to microorganisms, facilitating their recognition and uptake by phagocytes?

Accepted Answer

C3b

Answer

Immunoglobulin G

Answer

Mannose-binding lectin

Answer

Lipopolysaccharide

Question 7

Which of the following is NOT a mechanism by which innate immunity can restrict viral replication?

Accepted Answer

Production of antibodies

Answer

Production of interferons

Answer

Activation of the complement system

Answer

Phagocytosis of virus-infected cells

Question 8

What is the type of immunity that develops after exposure to a specific pathogen called?

Accepted Answer

Adaptive immunity

Answer

Innate immunity

Answer

Passive immunity

Answer

Natural immunity

Question 9

Which type of immune cell is directly involved in recognizing and destroying virus-infected cells?

Accepted Answer

Natural killer cell

Answer

B lymphocyte

Answer

T lymphocyte

Answer

Dendritic cell

Question 10

Which characteristic is NOT associated with the adaptive immune system?

Accepted Answer

Innate recognition of pathogens

Answer

Antigen specificity and tailored responses

Answer

Clonal expansion and generation of effector cells

Answer

Formation of immunological memory

Question 11

Which therapeutic approach targets innate immune pathways to potentially enhance protection against infections?

Accepted Answer

Use of TLR agonists to stimulate immune responses

Answer

Administration of anti-inflammatory drugs

Answer

Treatment with antibiotics to directly kill bacteria

Answer

Vaccination to induce adaptive immunity

Question 12

How does innate immunity facilitate the initiation of adaptive immune responses?

Accepted Answer

Dendritic cells present processed antigens to T cells, triggering T cell activation and clonal expansion.

Answer

Neutrophils and macrophages release cytokines that directly activate B cells.

Answer

Inflammatory mediators recruit natural killer cells to the infection site, where they release cytotoxic granules.

Answer

Phagocytes release antimicrobial peptides that directly target and destroy pathogens.

Question 13

Which of the following is NOT a component of the innate immune system?

Accepted Answer

Antibodies

Answer

Phagocytes

Answer

Natural killer cells

Answer

Cytokines

Question 14

What is the primary function of natural killer cells?

Accepted Answer

Killing virus-infected cells

Answer

Producing antibodies

Answer

Releasing cytokines

Answer

Activating macrophages

Question 15

What is the primary role of toll-like receptors in innate immunity?

Accepted Answer

Recognizing pathogen-associated molecular patterns

Answer

Producing antibodies

Answer

Activating complement proteins

Answer

Killing infected cells

Question 16

Which of the following is an example of an adaptive immune response?

Accepted Answer

Antibody production

Answer

Phagocytosis

Answer

Inflammation

Answer

Release of cytokines

Question 17

What is the primary function of the complement system?

Accepted Answer

Enhancing phagocytosis of microbes

Answer

Neutralizing viruses

Answer

Degrading pathogens

Answer

Releasing histamine

Question 18

Which of the following is a characteristic of innate immunity?

Accepted Answer

Rapid response

Answer

Specific pathogen recognition

Answer

Memory of infections

Answer

Production of antibodies

Question 19

What is the primary role of interferons in innate immunity?

Accepted Answer

Inhibiting viral replication

Answer

Killing infected cells

Answer

Activating macrophages

Answer

Producing antibodies

Question 20

Which of the following conditions can result from a deficiency in innate immunity?

Accepted Answer

Cystic fibrosis

Answer

HIV

Answer

Autoimmune disease

Answer

Allergies

Question 21

How does the complement system promote opsonization and enhance phagocytic activity?

Accepted Answer

By binding to pathogens and marking them for destruction

Answer

By producing antibodies that neutralize pathogens

Answer

By releasing cytokines that attract immune cells to the site of infection

Answer

By directly stimulating the production of antimicrobial peptides

Question 22

Which component is NOT part of the innate immune system?

Accepted Answer

Adaptive antibodies

Answer

Phagocytic cells

Answer

Inflammatory mediators

Answer

Natural killer cells

Question 23

Which cells are responsible for phagocytosis?

Accepted Answer

Neutrophils and macrophages

Answer

Natural killer cells

Answer

Dendritic cells

Answer

Basophils

Question 24

What do natural killer cells release to kill infected cells?

Accepted Answer

Perforin and granzymes

Answer

Antibodies

Answer

Cytokines

Answer

Complement proteins

Question 25

What primary function do Toll-like receptors (TLRs) perform?

Accepted Answer

Acknowledge pathogen-associated molecular patterns (PAMPs)

Answer

Activate the adaptive immune response

Answer

Produce antibodies

Answer

Regulate inflammation

Question 26

Which cytokine is crucial for the acute phase response?

Accepted Answer

Interleukin-6

Answer

Interleukin-10

Answer

Transforming growth factor-β

Answer

Interferon-α

Question 27

What primarily triggers the activation of the innate immune system?

Accepted Answer

Recognition of conserved molecular patterns on pathogens

Answer

Antigen presentation to T cells

Answer

Somatic hypermutation

Answer

Class switching

Question 28

Which characteristics define the inflammatory response?

Accepted Answer

Vasodilation, edema, and leukocyte recruitment

Answer

Antigen presentation and activation of T cells

Answer

Production of antibodies

Answer

Clonal expansion of B cells

Question 29

Which of the following cell types does NOT participate in the phagocytosis process?

Accepted Answer

Lymphocytes

Answer

Neutrophils

Answer

Macrophages

Answer

Eosinophils

Question 30

The process by which microorganisms trigger the release of inflammatory mediators is known as:

Accepted Answer

Inflammation

Answer

Opsonization

Answer

Phagocytosis

Answer

Complement activation

Question 31

Natural killer cells, as effector lymphocytes, target and eliminate:

Accepted Answer

Cancerous cells

Answer

Bacteria

Answer

Viruses

Answer

Parasites

Question 32

Which substance enhances the recognition and engulfment of pathogens by phagocytes by binding to them?

Accepted Answer

Complement proteins

Answer

Immunoglobulin G

Answer

Interferon gamma

Answer

Tumor necrosis factor alpha

Question 33

Which innate immune response involves the release of antimicrobial peptides?

Accepted Answer

Chemical barriers

Answer

Physical barriers

Answer

Cellular barriers

Answer

Humoral barriers

Question 34

The innate immune system primarily functions to:

Accepted Answer

Offer immediate defense against infections

Answer

Provide long-lasting immunity

Answer

Recognize specific pathogens

Answer

Generate memory cells

Question 35

The innate immune system is triggered by the presence of:

Accepted Answer

Pathogen-associated molecular patterns

Answer

Antigen-presenting cells

Answer

Cytokines

Answer

Antibodies

Question 36

How do genetic variations influence the effectiveness of innate immune responses? Provide specific examples to illustrate your answer.

Accepted Answer

Genetic variations can alter the expression of pattern recognition receptors (PRRs), affecting their ability to recognize and respond to pathogens.

Answer

Genetic variations have no impact on the effectiveness of innate immune responses.

Answer

Genetic variations solely affect the adaptive immune system, not the innate immune system.

Answer

Genetic variations can enhance the specificity of innate immune responses but have no impact on their efficiency.

Question 37

What is the primary function of natural killer (NK) cells?

Accepted Answer

Killing of infected cells

Answer

Phagocytosis

Answer

Antibody production

Answer

Antigen presentation

Question 38

Which of the following is a pattern recognition receptor (PRR) that recognizes viral RNA?

Accepted Answer

C-type lectin receptor (CLR)

Answer

Toll-like receptor 2 (TLR2)

Answer

Toll-like receptor 4 (TLR4)

Answer

NOD-like receptor (NLR)

Question 39

A patient presents with fever, chills, and muscle aches. Which of the following innate immune mechanisms is most likely contributing to these symptoms?

Accepted Answer

Inflammation

Answer

Phagocytosis

Answer

Natural killer cell activity

Answer

Adaptive immune response

Question 40

Which of the following statements best describes the role of the complement system in innate immunity?

Accepted Answer

It enhances phagocytosis and inflammation.

Answer

It directly kills invading microorganisms.

Answer

It activates adaptive immune responses.

Answer

It provides passive immunity to newborns

Question 41

Which of the following is a defining characteristic of innate immunity?

Accepted Answer

Rapid and non-specific response to pathogens

Answer

Highly specific for particular antigens

Answer

Acquired through vaccination

Question 42

Which type of phagocytic cell is primarily responsible for engulfing and destroying pathogens?

Accepted Answer

Neutrophils

Answer

T lymphocytes

Answer

Erythrocytes

Answer

Platelets

Question 43

C3a is a key component of which immune system pathway?

Accepted Answer

Complement system

Answer

Immunoglobulin response

Answer

Interferon pathway

Answer

Cytokine cascade

Question 44

Natural killer (NK) cells primarily function in:

Accepted Answer

Cytotoxic elimination of infected or cancerous cells

Answer

Antibody production

Answer

Complement activation

Answer

Antigen presentation

Question 45

Which cytokine is a key mediator of the innate immune response to viral infections?

Accepted Answer

Interferon-alpha

Answer

Interleukin-4

Answer

Tumor necrosis factor-alpha

Answer

Interleukin-10

Question 46

Which of the following barriers is NOT part of the innate immune system's defense mechanisms?

Accepted Answer

Adaptive antibodies

Answer

Skin

Answer

Mucous membranes

Question 47

Innate immunity can be influenced by which of the following?

Accepted Answer

All of the following

Answer

Genetic factors

Answer

Lifestyle choices

Answer

Environmental factors

Question 48

Which of the following characteristics is NOT associated with innate immunity?

Accepted Answer

Acquired specificity for specific pathogens

Answer

Rapid response to infection

Answer

Immediate recognition of common pathogens

Answer

Lack of memory for past infections

Question 49

Phagocytosis is a process where:

Accepted Answer

Cells engulf and destroy pathogens and cellular debris

Answer

Complement proteins directly lyse pathogens

Answer

Natural killer cells target and kill infected cells

Answer

Antibodies bind and neutralize pathogens

Question 50

Which of these cell types is NOT directly involved in phagocytosis?

Accepted Answer

B lymphocytes

Answer

Dendritic cells

Answer

Neutrophils

Answer

Macrophages

Question 51

Inflammation is characterized by the following cardinal signs:

Accepted Answer

Redness, swelling, heat, and pain

Answer

Sneezing, coughing, and watery eyes

Answer

Fever, chills, and muscle aches

Answer

Skin rash, itching, and hives

Question 52

Which of the following cytokines is a primary mediator of inflammation?

Accepted Answer

Tumor necrosis factor-alpha (TNF-α)

Answer

Interferon gamma (IFN-γ)

Answer

Transforming growth factor-beta (TGF-β)

Answer

Interleukin-10 (IL-10)

Question 53

Interferons are classified as:

Accepted Answer

Cytokines

Answer

Antigens

Answer

Antibodies

Question 54

Which of the following is a major physical barrier to infection?

Accepted Answer

Skin

Answer

Lymph nodes

Answer

Spleen

Answer

Bone marrow

Question 55

The innate immune system is:

Accepted Answer

Present at birth and provides immediate protection

Answer

Highly specific in its recognition of individual pathogens

Answer

Acquired through exposure to specific pathogens

Answer

Responsible for long-lasting, specific immunity