Antibodies: Structure, Function, and Diversity - Immunology Quiz

Question 1

What is the primary function of the variable (V) region in an antibody?

Accepted Answer

Dictating the specific antigen an antibody can bind.

Answer

Binding to a wide range of antigens due to high conservation.

Answer

Forming the structure with two heavy and two light chains.

Answer

Providing protection from degradation through glycosylation.

Question 2

An antibody is composed of which primary structural components, and what are their respective roles in antibody function?

Accepted Answer

Two heavy chains and two light chains, each with a constant region for effector functions and a variable region for antigen binding

Answer

Four identical chains, each with only a variable region for binding to different epitopes on an antigen

Answer

Two heavy chains and two light chains, each with only a constant region for antigen binding and a variable region for effector functions

Question 3

Which region of an antibody directly interacts with the antigen?

Accepted Answer

Fab region

Answer

Fc region

Answer

Hinge region

Answer

Constant region

Question 4

Antibody-dependent cell-mediated cytotoxicity (ADCC) is a mechanism by which antibodies facilitate the killing of target cells through the action of:

Accepted Answer

Natural killer cells

Answer

Macrophages

Answer

Neutrophils

Answer

Eosinophils

Question 5

Which antibody class is primarily involved in the activation of the complement system?

Accepted Answer

IgM

Answer

IgG

Answer

IgA

Answer

IgE

Question 6

Systemic lupus erythematosus (SLE) is an autoimmune disease in which the immune system produces antibodies against:

Accepted Answer

Self-antigens

Answer

Foreign antigens

Answer

Tumor antigens

Answer

Viral antigens

Question 7

Immunogenicity is a potential concern with antibody-based therapies due to the risk of:

Accepted Answer

Developing antibodies against the therapeutic antibody

Answer

Excessive activation of the immune system

Answer

Reduced efficacy of the antibody

Answer

Increased risk of allergic reactions

Question 8

Rituximab, a monoclonal antibody used to treat non-Hodgkin lymphoma, primarily targets:

Accepted Answer

B cells

Answer

T cells

Answer

Macrophages

Answer

Neutrophils

Question 9

The specific region of an antigen recognized and bound by the antibody paratope is called the:

Accepted Answer

Epitope

Answer

Paratope

Answer

Fab fragment

Answer

Fc fragment

Question 10

Which process is crucial for generating the vast diversity of antibodies?

Accepted Answer

Somatic hypermutation

Answer

Class switch recombination

Answer

T cell activation

Answer

B cell differentiation

Question 11

A key characteristic of monoclonal antibodies is that they are:

Accepted Answer

Derived from a single clone of B cells

Answer

Bind to a broad range of epitopes

Answer

Produced by multiple B cell clones

Answer

Highly specific towards self-antigens

Question 12

Which technique is commonly used to quantify antibody levels in a sample?

Accepted Answer

Enzyme-linked immunosorbent assay (ELISA)

Answer

Western blotting

Answer

Immunofluorescence

Answer

Flow cytometry

Question 13

The monoclonal antibody Rituximab, used in treating B cell lymphomas, targets which surface protein?

Accepted Answer

CD20

Answer

CD3

Answer

CD40

Answer

CD80

Question 14

What is the process by which antibodies selectively recognize and bind to specific antigens called?

Accepted Answer

Epitope binding

Answer

Affinity

Answer

Avidity

Answer

Cross-reactivity

Question 15

Which of the following best describes the relationship between antibody structure and function?

Accepted Answer

Variable region: specificity; Constant region: effector functions

Answer

Glycosylation: enhanced antigen binding

Answer

Fc region: both antigen binding and effector responses

Answer

Antibody structure: identical across individuals

Question 16

Which of the following is the primary structure of an antibody? (Linear polypeptide chain)

Accepted Answer

Linear chain of amino acids

Answer

Branched polypeptide chain

Answer

Cyclic peptide ring

Answer

Globular protein

Question 17

What is the main function of the Fab region of an antibody?

Accepted Answer

Binding to the antigen

Answer

Activating complement

Answer

Cross-linking antigen-presenting cells

Answer

Opsonizing pathogens

Question 18

Which antibody class is particularly efficient in activating the complement system?

Accepted Answer

IgM

Answer

IgG

Answer

IgA

Answer

IgE

Question 19

What is the process by which antibodies are produced in response to the presence of an antigen?

Accepted Answer

Clonal selection

Answer

Antigen presentation

Answer

T cell activation

Answer

Immunologic memory

Question 20

Which option is NOT related to antibody diversity?

Accepted Answer

Constant region genes

Answer

Variable region genes

Answer

Somatic hypermutation

Answer

Class switching

Question 21

What is the primary role of the FcRn receptor in antibody homeostasis?

Accepted Answer

Protecting antibodies from degradation

Answer

Facilitating transplacental antibody transfer

Answer

Activating complement

Answer

Binding to antigen-presenting cells

Question 22

What is the primary mechanism by which antibodies neutralize viruses?

Accepted Answer

Blocking viral entry into host cells

Answer

Binding to viral surface proteins

Answer

Promoting viral degradation

Answer

Stimulating antibody-dependent cell-mediated cytotoxicity

Question 23

Which of the following accurately describes the primary function of antibodies in humoral immunity?

Accepted Answer

Enhancing phagocytosis of pathogens by macrophages

Answer

Signaling the presence of an antigen

Answer

Directly destroying foreign pathogens

Answer

Suppressing the immune response

Question 24

Which region of an antibody is responsible for binding specifically to antigens?

Accepted Answer

Fab region

Answer

Fc region

Answer

Hinge region

Answer

Constant region

Question 25

What is the primary function of Fc receptors in antibody-mediated immunity?

Accepted Answer

Activating effector cells, such as macrophages and neutrophils

Answer

Binding to antigens

Answer

Transporting antibodies across membranes

Answer

Suppressing the immune response

Question 26

Which of the following characteristics is unique to monoclonal antibodies?

Accepted Answer

Produced by a single B cell clone, resulting in high specificity for a single antigen

Answer

Specific for multiple antigens

Answer

Found in serum

Answer

Have short half-lives

Question 27

What is the main advantage of antibody diversity in the immune system?

Accepted Answer

Recognition of a wide range of antigens, enabling effective defense against infections

Answer

Prevention of autoimmune diseases

Answer

Enhancement of the inflammatory response

Answer

Suppression of the immune system

Question 28

Which technique is commonly used to measure the concentration of antibodies in a sample?

Accepted Answer

ELISA (Enzyme-Linked Immunosorbent Assay)

Answer

Western blotting

Answer

Polymerase chain reaction

Answer

Flow cytometry

Question 29

What is a potential clinical consequence of autoantibodies?

Accepted Answer

Autoimmune diseases, where the immune system mistakenly attacks the body's own tissues

Answer

Enhanced immune responses

Answer

Harmless effects

Answer

Suppression of the immune system

Question 30

Which of the following is NOT a medical application of antibodies?

Accepted Answer

Water purification

Answer

ELISA (Enzyme-linked immunosorbent assay)

Answer

Immunohistochemistry

Answer

Flow cytometry

Question 31

Which of the following is NOT a key structural feature of antibodies?

Accepted Answer

A hydrophobic core that stabilizes the antibody structure

Answer

Variable regions that bind to specific antigens

Answer

Constant regions that mediate effector functions

Answer

Glycosylation sites that enhance antibody stability and function

Question 32

Which cellular process leads to the production of antibodies?

Accepted Answer

B cell activation and differentiation into antibody-producing cells

Answer

T cell activation and cytokine release

Answer

Macrophage phagocytosis and antigen presentation

Answer

Neutrophil degranulation and release of antimicrobial peptides

Question 33

Which laboratory technique is commonly used to measure antibody levels in a sample?

Accepted Answer

ELISA, an immunoassay detecting antigen-antibody reactions

Answer

Western blot, a technique used to identify specific proteins

Answer

Immunofluorescence, a method for visualizing antibody binding to antigens in cells or tissues

Answer

Flow cytometry, a technique used to analyze cell populations and their surface markers

Question 34

Which region of an antibody specifically binds to an antigen?

Accepted Answer

Variable region

Answer

Fc region

Answer

Constant region

Answer

Hinge region

Question 35

What is the primary function of the Fc region of antibodies?

Accepted Answer

Binds to receptors on immune cells

Answer

Recognizes antigens on pathogens

Answer

Activates complement pathways

Answer

Neutralizes toxins

Question 36

Which antibody isotype is primarily produced during the early stages of a primary immune response?

Accepted Answer

IgM

Answer

IgG

Answer

IgA

Answer

IgE

Question 37

Which antibody isotype is associated with immediate hypersensitivity reactions?

Accepted Answer

IgE

Answer

IgG

Answer

IgA

Question 38

What is the primary function of memory B cells in the adaptive immune response?

Accepted Answer

Provide rapid and amplified antibody response upon secondary exposure to an antigen

Answer

Opsonize pathogens for phagocytosis

Answer

Produce antibodies that neutralize pathogens

Question 39

Which antibody class is primarily responsible for mediating immediate hypersensitivity reactions?

Accepted Answer

IgE

Answer

IgD

Answer

IgM

Answer

IgG

Question 40

A patient presents with recurrent bacterial infections.  Laboratory tests reveal low levels of IgG. What is the most likely explanation for this patient's condition?

Accepted Answer

Defective antibody production

Answer

Insufficient antigen exposure

Answer

Increased antibody degradation

Answer

Overactive immune response

Question 41

Which region of an antibody molecule is responsible for binding to specific antigens?

Accepted Answer

Fab (Fragment antigen-binding) region

Answer

Constant region

Answer

Hinge region

Answer

Fc region

Question 42

A patient with a history of respiratory infections is found to have a deficiency in IgA. What is the most likely reason for the patient's susceptibility to these infections?

Accepted Answer

Reduced mucosal immunity

Answer

Inability to activate complement

Answer

Impaired opsonization of pathogens

Answer

Defective antibody-dependent cellular cytotoxicity (ADCC)

Question 43

Which of the following best describes the process of neutralization by antibodies?

Accepted Answer

Blocking the binding of a pathogen to its target cell or molecule

Answer

Activating complement cascade

Answer

Directly lysing the pathogen

Question 44

Which of the following statements about the antibody response to a primary infection is true?

Accepted Answer

The initial antibody response is IgM-dominated, with IgG production increasing over time.

Answer

Memory B cells are readily available.

Answer

IgG levels are elevated quickly and remain high.

Question 45

A patient receives a vaccine against a particular pathogen. What type of antibody response is primarily responsible for providing long-term protection?

Accepted Answer

Memory B cell activation and subsequent IgG production

Answer

Immediate IgE production

Answer

Complement activation by IgM

Answer

Production of high levels of IgM

Question 46

Which of the following is a defining feature of monoclonal antibodies?

Accepted Answer

They are produced by a single clone of B cells and therefore target a specific antigen.

Answer

They are highly diverse in their antigen specificity.

Answer

They are effective against a broad range of antigens.

Answer

They are naturally occurring in the body.

Question 47

What is the primary function of the Fc region of an antibody?

Accepted Answer

Binds to effector cells

Answer

Neutralizes toxins

Answer

Activates complement

Answer

Binds to antigen

Question 48

What is the role of memory B cells in humoral immunity?

Accepted Answer

Provide a rapid and robust secondary immune response

Answer

Produce antibodies against new antigens

Answer

Secrete cytokines

Question 49

What is a polyclonal antibody preparation?

Accepted Answer

Contains a mixture of antibodies against multiple antigens

Answer

Contains only one type of antibody

Answer

Is produced by a single clone of B cells

Question 50

What is the difference between affinity and avidity?

Accepted Answer

Affinity measures the binding strength of a single antibody-antigen interaction, while avidity measures the overall strength of multiple antibody-antigen interactions

Answer

Affinity is a measure of antibody specificity, while avidity is a measure of antibody concentration