Chapter 16 (Unit 4 Exam) Flashcards
(36 cards)
The four stages of an adaptive immune response include ________, ________, ________, and ________.
Recognition, Activation, Response, Memory
Explanation: An adaptive immune response proceeds through stages of recognizing the antigen, activating immune cells, responding to the infection, and creating a memory for a quicker response upon re-exposure.
During the development of B and T cells, B cells mature in the __________, while T cells mature in the __________.
bone marrow, thymus
Explanation: B cells undergo maturation in the bone marrow where they develop immunoglobulins as surface receptors, whereas T cells mature in the thymus where they acquire T-cell receptors before migrating to lymphoid tissues.
An antibody binding an antigen can lead to which of the following end results?
Options:
A) Neutralization of the antigen, opsonization, complement activation, and immobilization of bacteria
B) Direct destruction of the pathogen’s DNA, alteration of the host’s immune response, and the production of mucus
C) Inhibition of phagocyte migration, suppression of cytokine release, and enhancement of pathogen growth
D) All of the above
A) Neutralization of the antigen, opsonization, complement activation, and immobilization of bacteria
Explanation: The binding of an antibody to an antigen can neutralize the antigen, make it easier for phagocytes to engulf by opsonization, activate the complement system which leads to the lysis of the pathogen, and immobilize bacteria preventing their spread.
The third line of adaptive immunity is acquired ____________ immunity that occurs after an immunizing event such as an infection or vaccination.
Specific
Explanation: The third line of adaptive immunity is specific and is a product of B and T lymphocytes, which undergo a selective process specializing them for reacting to only one specific antigen .
IgM antibodies are the first to be produced in response to an infection and are mainly found in the __________.
blood
Explanation: IgM is the largest antibody and is the first to increase in the immune response to an antigen. It is primarily found in the blood and is effective at forming complexes with antigens and activating the complement system.
During B-cell activation, the types of B cells produced include only plasma cells.
A) True
B) False
B) False
Explanation: B-cell activation leads to the production of both plasma cells, which secrete antibodies, and memory B cells, which provide long-term immunity.
What is the role of the major histocompatibility complex (MHC) in the immune system?
Options:
A) To produce antibodies against pathogens.
B) To act as physical barriers against infections.
C) To code for cell markers essential for immune system recognition of self.
D) To directly kill infected cells and pathogens.
C) To code for cell markers essential for immune system recognition of self.
Explanation: The MHC is a set of genes that code for markers on the surfaces of cells. These markers are essential for the immune system to distinguish self from non-self.
The role of cytotoxic T cells in apoptosis includes targeting __________ such as virally infected cells, tumor cells, and cells with intracellular bacteria or parasites.
abnormal or infected cells
Explanation: Cytotoxic T cells induce apoptosis in cells that are abnormal or infected with pathogens. They are critical for the immune response to virally infected cells, cancer cells, and cells with intracellular pathogens.
Immune system markers function in attaching to self-antigens and aid in cellular development.
A) True
B) False
B) False
Explanation: Immune system markers attach to non-self or foreign antigens, not self-antigens. They bind to cell surface receptors indicating “self,” transmit chemical messages to coordinate the immune response, and aid in cellular development.
Which of the following is NOT a characteristic of adaptive specific immunity?
A) Specificity
B) Memory
C) Diversity
D) Inducibility
E) Clonality
E) Clonality
Explanation: Adaptive specific immunity is characterized by its specificity for a particular antigen, the memory of past pathogens, and the diversity of lymphocytes to respond to any antigen. Clonality is not listed as a characteristic of adaptive immunity in the provided material.
What is the primary function of IgD antibodies?
Options:
A) To trigger the body’s immune response to parasites.
B) To neutralize bacterial toxins.
C) To signal the B cells to be activated.
D) To cross the placenta and provide immunity to the fetus.
C) To signal the B cells to be activated.
Explanation: IgD is found in small amounts in the blood, but is primarily located on the surface of B cells as a receptor. Its main function is believed to be the regulation of B-cell mediated immune responses.
IgE is involved in defense against parasitic infections and is also responsible for the symptoms of __________.
allergies
Explanation: IgE binds to allergens and triggers histamine release from mast cells and basophils, and is also associated with immunity to parasites like worms. This class of antibody is mainly responsible for the symptoms of allergic reactions, such as hay fever, asthma, and anaphylaxis.
The immune system responds to superantigens in a controlled manner, similar to how it responds to regular antigens.
A) True
B) False
B) False
Explanation: Superantigens are a class of antigens that cause non-specific activation of T-cells resulting in polyclonal T cell activation and massive cytokine release, which is not a controlled response.
The process of T-cell activation involves recognition of antigens presented by MHC molecules, followed by __________ and differentiation into various types of T cells.
clonal expansion
Explanation: T-cell activation is initiated by the recognition of antigens presented by MHC molecules on APCs. This triggers clonal expansion, where T cells proliferate and differentiate into effector cells and memory T cells.
T cells require the presence of specific markers or antigens to be activated, but B cells do not require antigen presentation with MHC to be activated.
A) True
B) False
A) True
Explanation: T cells indeed require antigen presentation alongside MHC molecules for activation. In contrast, most B cells can be activated without the need for antigens to be presented with MHC, though some B cells do require T cell help for activation.
In a graph illustrating the secondary immune response, the antibody level peaks later and lower than in the primary immune response.
A) True
B) False
B) False
Explanation: In a secondary immune response, the level of antibodies rises more quickly and to a higher level compared to the primary response due to the action of memory cells formed during the primary response.
IgA antibodies are most commonly associated with allergic reactions and protection against parasitic infections.
A) True
B) False
B) False
Explanation: IgA is found in mucous secretions and is important in local immunity on mucosal surfaces. It is not typically associated with allergic reactions; that role belongs to IgE, which is involved in allergic reactions and protection against parasitic infections.
Which types of cells can act as antigen-presenting cells?
Options:
A) Neutrophils, basophils, and eosinophils
B) Erythrocytes, platelets, and fibroblasts
C) Dendritic cells, macrophages, and B cells
D) Epithelial cells, endothelial cells, and adipocytes
C) Dendritic cells, macrophages, and B cells
Explanation: Antigen-presenting cells (APCs) such as dendritic cells, macrophages, and B cells are specialized to take up antigens, process them, and present them on their surface to T cells along with MHC molecules.
How is the third line of defense different from the first and second lines of host defense mechanisms?
Options:
A) It is non-specific and does not provide long-lasting immunity.
B) It consists only of physical barriers like skin and mucous membranes.
C) It is specific, has memory, and is adaptive, improving upon repeated exposure to a pathogen.
D) It acts immediately upon infection and does not change with repeated exposure.
C) It is specific, has memory, and is adaptive, improving upon repeated exposure to a pathogen.
Explanation: The third line of defense is the adaptive immune system, which is highly specific to the pathogen it targets. It has the ability to remember past infections and respond more effectively upon subsequent exposures.
List several types of vaccines and their current utilization. Which of the following is not a type of vaccine used today?
Options:
A) Live attenuated vaccines
B) Inactivated vaccines
C) Subunit vaccines
D) Magnetic vaccines
D) Magnetic vaccines
Explanation: Common types of vaccines include live attenuated vaccines, which use a weakened form of the germ; inactivated vaccines, which use a killed version; and subunit vaccines, which include parts of the germ like its protein. Magnetic vaccines are not a recognized type of vaccine in immunology.
Characteristics of antigens that optimize their immunogenicity include being foreign to the host, having high molecular weight, and being __________.
complex and stable
Explanation: The immunogenicity of an antigen is determined by several factors, including being foreign to the host’s immune system, having a large molecular weight, and possessing a complex, stable structure that the immune system can recognize and respond to.
An effective vaccine should be safe, provide long-lasting protection, be able to elicit a protective immune response, and be __________.
cost-effective
Explanation: The qualities of an effective vaccine include safety, immunogenicity (elicits the desired immune response), duration of protection (long-lasting), and being cost-effective to produce and distribute.
How do the terms antigen, immunogen, and epitope differ?
Options:
A) Antigens and immunogens are substances that elicit an immune response; epitopes are the part of antigens that interact with antibodies.
B) Antigens are the only substances that can trigger an immune response, while immunogens and epitopes cannot.
C) Immunogens are cells that produce antibodies, antigens cause disease, and epitopes are medications that enhance immunity.
D) Epitopes are cells that present antigens, and immunogens are the sites where antibodies bind.
A) Antigens and immunogens are substances that elicit an immune response; epitopes are the part of antigens that interact with antibodies.
Explanation: Antigens are substances that can be bound by an antibody or an antigen receptor on B and T cells, whereas immunogens are antigens that can elicit an immune response. An epitope is the specific part of the antigen that is recognized and bound by an antibody.
The process of antigen recognition is different in T cells and B cells because T cells recognize antigens with the help of ________ molecules, while B cells can recognize antigens directly with their ________ receptors.
MHC, B-cell
Explanation: T cells require antigens to be presented with MHC molecules to recognize them, whereas B cells have B-cell receptors that can directly bind to antigens without MHC presentation.
