Adaptive Immunity: A Comprehensive Guide for Medical Students

Question 1

Which type of cell presents antigens to helper T cells, initiating the adaptive immune response?

Accepted Answer

Dendritic cells

Answer

B cells

Answer

Macrophages

Answer

Natural killer cells

Question 2

Which cytokine plays a key role in promoting the development of Th2 cells, which are involved in humoral immune responses?

Accepted Answer

Interleukin-4

Answer

Interleukin-12

Answer

Interferon-gamma

Answer

Tumor necrosis factor

Question 3

Which type of T cell is responsible for directly killing infected cells?

Accepted Answer

Cytotoxic T cells

Answer

Th1 cells

Answer

Th2 cells

Answer

Regulatory T cells

Question 4

Which class of the major histocompatibility complex (MHC) is primarily responsible for presenting antigens to CD8+ T cells?

Accepted Answer

MHC class I

Answer

MHC class II

Answer

Both MHC class I and II

Answer

Neither MHC class I nor II

Question 5

Which class of antibody is most effective in neutralizing viruses and preventing their entry into host cells?

Accepted Answer

IgG

Answer

IgA

Answer

IgE

Answer

IgM

Question 6

Which of the following is a type of hypersensitivity reaction characterized by immediate symptoms such as sneezing, runny nose, and watery eyes?

Accepted Answer

Type I: immediate allergy

Answer

Type II: antibody-mediated

Answer

Type III: immune complex

Answer

Type IV: delayed-type hypersensitivity

Question 7

How does clonal expansion contribute to the specificity and diversity of the adaptive immune response?

Accepted Answer

Amplifies antigen-specific T cells, enhancing response specificity and strength

Answer

Introduces new antigen specificities into the immune repertoire

Answer

Increases T cell affinity for MHC-antigen complexes

Answer

Reduces the diversity of the adaptive immune response

Question 8

Which event initiates the adaptive immune response?

Accepted Answer

Recognition of an antigen by an antigen-presenting cell

Answer

Expansion of antigen-specific T cells

Answer

Production of antibodies by B cells

Answer

Release of cytokines by T cells

Question 9

What is the primary role of MHC molecules?

Accepted Answer

To present antigens to T cells

Answer

To stimulate B cells to produce antibodies

Answer

To bind directly to pathogens

Answer

To release cytokines

Question 10

What is the defining feature of cell-mediated immunity?

Accepted Answer

Destroys infected cells

Answer

Uses antibodies

Answer

Produces memory cells

Answer

Recognizes extracellular antigens

Question 11

Which cells are central to both humoral and cell-mediated immunity?

Accepted Answer

T cells

Answer

B cells

Answer

Macrophages

Answer

Neutrophils

Question 12

What is the intended purpose of immune checkpoint inhibitors?

Accepted Answer

To enhance immune response against cancer

Answer

To suppress immune responses in autoimmune diseases

Answer

To prevent organ rejection in transplant patients

Answer

To treat bacterial infections

Question 13

What is the primary role of cytokines in adaptive immunity?

Accepted Answer

To regulate immune cell differentiation and function

Answer

To directly neutralize pathogens

Answer

To initiate the complement cascade

Answer

To enhance phagocytosis

Question 14

What is the key advantage of adaptive immunity over innate immunity?

Accepted Answer

Both specificity and memory

Answer

Specificity

Answer

Memory

Answer

Neither specificity nor memory

Question 15

Which mechanisms are involved in cytotoxic T cell killing?

Accepted Answer

Fas-FasL interaction and release of perforin and granulysin

Answer

Antibody-dependent cell-mediated cytotoxicity and complement activation

Answer

Cytokine release and activation of natural killer cells

Question 16

Which of the following mechanisms is crucial in preventing the development of autoimmune disorders?

Accepted Answer

Clonal anergy

Accepted Answer

Clonal deletion

Answer

Immunoglobulin class switching

Answer

Cytokine production

Question 17

Which immune cell type presents antigens to T cells?

Accepted Answer

Dendritic cells

Answer

Macrophages

Answer

B cells

Answer

Eosinophils

Question 18

The rapid clonal expansion and differentiation of B cells into antibody-producing plasma cells is termed:

Accepted Answer

Germinal center reaction

Answer

Somatic hypermutation

Answer

Class switching

Answer

Affinity maturation

Question 19

Cell-mediated immunity is characterized by the ability to:

Accepted Answer

Recognize infected cells

Answer

Produce antibodies

Answer

Activate complement

Answer

Opsonize pathogens

Question 20

Antibodies that are specific for a particular antigen are known as:

Accepted Answer

Immunoglobulins

Answer

Hypersensitivity

Answer

Complement activation

Answer

Antibody-dependent cell-mediated cytotoxicity

Question 21

The process by which antibody affinity for an antigen increases over time is known as:

Accepted Answer

Affinity maturation

Answer

Somatic hypermutation

Answer

Class switching

Answer

Germinal center reaction

Question 22

The primary function of cytotoxic T cells is to:

Accepted Answer

Release cytotoxic granules

Answer

Produce antibodies

Answer

Activate macrophages

Answer

Opsonize pathogens

Question 23

Which cytokine is a key regulator of Th2 cell differentiation?

Accepted Answer

IL-4

Answer

IL-8

Answer

IFN-γ

Answer

TNF-α

Question 24

The generation of memory cells during an immune response is essential for:

Accepted Answer

Rapid response to subsequent infections

Answer

Antibody production without antigen presence

Answer

T cell activation via MHC-I

Answer

Granulocyte recruitment to inflammation sites

Question 25

How does immunological memory contribute to the enhanced and accelerated adaptive immune response during subsequent encounters with specific pathogens?

Accepted Answer

Immunological memory involves long-lived memory cells that continuously circulate, providing a pool of ready-to-respond cells.

Answer

Immunological memory solely involves the production of new antibodies without the involvement of memory cells.

Answer

Memory cells have reduced affinity for specific antigens compared to naïve lymphocytes.

Answer

Immunological memory is independent of prior antigen exposure.

Question 26

Explain the molecular mechanisms that enable antibody production and describe how these mechanisms contribute to the remarkable diversity of antibody specificities within the immune system.

Accepted Answer

Antibody genes undergo extensive rearrangement and mutation, generating a vast repertoire of unique antibody specificities.

Answer

Antibodies are produced in large quantities by a single clone of B cells, resulting in antibody diversity.

Answer

Antibody diversity is primarily due to variations in the heavy chain constant region.

Answer

All antibodies have the same specificity for a single antigen.

Question 27

Immune checkpoints are molecules that play a crucial role in regulating immune responses. What is their primary function?

Accepted Answer

Inhibiting immune cell activation

Answer

Activating T cells

Answer

Recognizing antigens

Answer

Producing antibodies

Question 28

Immunological tolerance refers to:

Accepted Answer

A state of unresponsiveness to self-antigens to prevent autoimmune reactions.

Answer

A state of heightened responsiveness to foreign antigens to enhance immune defense.

Answer

A state of decreased responsiveness to all antigens, leading to immunosuppression.

Question 29

Which molecular interaction initiates the T cell response?

Accepted Answer

TCR complex binds to a peptide fragment presented by MHC.

Answer

TCR directly binds to the MHC antigen-binding groove.

Answer

TCR complex binds to the MHC constant region.

Answer

TCR complex binds to CD4 or CD8 co-receptors.

Question 30

Which type of lymphocyte is responsible for producing antibodies?

Accepted Answer

B cell

Answer

T cytotoxic cell

Answer

Natural killer cell

Answer

T helper cell

Question 31

What is the process by which T cells become activated and proliferate in response to an antigen?

Accepted Answer

Clonal expansion

Answer

Isotype switching

Answer

Somatic hypermutation

Answer

Antigen presentation

Question 32

What is the role of MHC molecules in adaptive immunity?

Accepted Answer

Present antigens to T cells

Answer

Engulf pathogens

Answer

Produce cytokines

Answer

Activate B cells

Question 33

Which of the following cells is NOT involved in the adaptive immune response?

Accepted Answer

Neutrophil

Answer

B cell

Answer

Dendritic cell

Answer

T cell

Question 34

What is the difference between a primary and a secondary immune response?

Accepted Answer

Secondary response is faster and more robust

Answer

Secondary response is more specific

Answer

Primary response is more specific

Answer

Primary response is faster and more robust

Question 35

Which of the following is a characteristic of adaptive immunity?

Accepted Answer

Specificity

Answer

Non-specific

Answer

Short-lived

Answer

Innate

Question 36

What is the difference between humoral and cell-mediated immunity?

Accepted Answer

Humoral immunity involves antibodies, while cell-mediated immunity involves T cells

Answer

Humoral immunity involves T cells, while cell-mediated immunity involves antibodies

Answer

Humoral immunity is non-specific, while cell-mediated immunity is specific

Question 37

Which cell type plays a dominant role in antibody production within the adaptive immune response?

Accepted Answer

B cell

Answer

Neutrophil

Answer

T cell

Answer

Macrophage

Question 38

Within the adaptive immune response, which process leads to the expansion of lymphocytes into effector cells?

Accepted Answer

Clonal expansion

Answer

Somatic hypermutation

Answer

Isotype switching

Answer

Affinity maturation

Question 39

Which type of molecule is responsible for specific antigen recognition within adaptive immunity?

Accepted Answer

Immunoglobulin

Answer

Cytokine

Answer

Histamine

Answer

Interferon

Question 40

In the context of adaptive immunity, which cell type is responsible for eliminating virus-infected cells?

Accepted Answer

Cytotoxic T cell

Answer

B cell

Answer

Helper T cell

Answer

Regulatory T cell

Question 41

Within adaptive immunity, which cytokine plays a pivotal role in B cell activation?

Accepted Answer

Interleukin-4

Answer

Interferon-gamma

Answer

Tumor necrosis factor-alpha

Answer

Interleukin-2

Question 42

Which receptor is commonly expressed on the surface of all T cells?

Accepted Answer

TCR

Answer

FcR

Answer

MHC

Answer

IgE

Question 43

In adaptive immunity, which type of cell presents antigens to T cells in conjunction with MHC class II molecules?

Accepted Answer

Antigen-presenting cell

Answer

Helper T cell

Answer

B cell

Answer

Cytotoxic T cell

Question 44

Amongst immunoglobulins, which type is predominantly involved in mucosal immunity?

Accepted Answer

IgA

Answer

IgE

Answer

IgG

Answer

IgM

Question 45

Within adaptive immunity, which mechanism provides long-term protection against infections?

Accepted Answer

Memory cells

Answer

Vaccination

Answer

Inflammation

Answer

Antibody production

Question 46

Which immune cell type is principally responsible for antibody production?

Accepted Answer

B cell

Answer

Macrophage

Answer

T cell

Answer

Neutrophil

Question 47

What type of immunity involves the activation of cytotoxic T cells to directly eliminate infected cells?

Accepted Answer

Cell-mediated immunity

Answer

Passive immunity

Answer

Innate immunity

Answer

Humoral immunity

Question 48

What is the primary function of MHC class II molecules?

Accepted Answer

Present antigens to helper T cells

Answer

Present antigens to cytotoxic T cells

Answer

Secrete cytokines

Answer

Bind to antibodies

Question 49

What is the purpose of clonal expansion in adaptive immunity?

Accepted Answer

To generate a large population of antigen-specific lymphocytes

Answer

To enhance antibody affinity

Answer

To stimulate innate immune cells

Question 50

Which cytokine is crucial for the differentiation of Th2 cells?

Accepted Answer

IL-4

Answer

IL-10

Answer

IFN-γ

Answer

IL-2

Question 51

What is the primary function of memory T cells?

Accepted Answer

Provide rapid and robust immune responses upon subsequent encounters with specific antigens

Answer

Phagocytose pathogens

Answer

Produce antibodies

Question 52

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

Accepted Answer

Specificity and immunological memory

Answer

Immediate response

Answer

Reliance on pre-existing receptors

Answer

Recognition of self and non-self

Question 53

What is the role of dendritic cells in adaptive immunity?

Accepted Answer

Present antigens and activate T cells

Answer

Produce antibodies

Answer

Release histamine

Answer

Kill infected cells

Question 54

What is the key difference between primary and secondary immune responses?

Accepted Answer

Primary response is slower and produces lower affinity antibodies, while secondary response is rapid and produces higher affinity antibodies.

Answer

Primary response produces memory cells, while secondary response does not.