Question 1

Which of the following statements about the major histocompatibility complex (MHC) is true?

Accepted Answer

A)  MHC molecules are expressed on professional antigen-presenting cells such as dendritic cells, macrophages and B cells. 
B)  MHC molecules do not influence the production of immunoglobulins although they must bind antigens before TCRs will recognise the antigen. 
C)  MHC molecules are expressed only on activated T-cells to enable recognition of specific antigens. 
D)  MHC molecules are coded for by the multigene complex, which is located with the variable (V) genes and joining (J) elements rather than the constant (
C)  gene or diversity (
D)  elements. 
E)  The MHC restriction concept is particularly important in modern immunology because it details the categories of antigens capable of binding to MHC molecules. 
A)  MHC molecules are expressed on professional antigen-presenting cells such as dendritic cells, macrophages and B cells. 
B)  MHC molecules do not influence the production of immunoglobulins although they must bind antigens before TCRs will recognise the antigen. 
C)  MHC molecules are expressed only on activated T-cells to enable recognition of specific antigens. 
D)  MHC molecules are coded for by the multigene complex, which is located with the variable (V) genes and joining (J) elements rather than the constant (
C)  gene or diversity (
D)  elements. 
E)  The MHC restriction concept is particularly important in modern immunology because it details the categories of antigens capable of binding to MHC molecules.

Question 2

Phagocytes

Accepted Answer

A)  are of two main types: mononuclear phagocytes such as granulocytes, and polymorphs such as macrophages. 
B)  include monocytes found principally in tissues, rather than circulating in blood. 
C)  include the polymorphonuclear granulocytes and macrophages. 
D)  include dendritic cells that are confined to strategic locations in the lymphatic system such as the Kupffer cells of the liver which can present antigens to T and B cells. 
E)  are specific effector cells which engulf bacteria in response to secondary infection. 
A)  are of two main types: mononuclear phagocytes such as granulocytes, and polymorphs such as macrophages. 
B)  include monocytes found principally in tissues, rather than circulating in blood. 
C)  include the polymorphonuclear granulocytes and macrophages. 
D)  include dendritic cells that are confined to strategic locations in the lymphatic system such as the Kupffer cells of the liver which can present antigens to T and B cells. 
E)  are specific effector cells which engulf bacteria in response to secondary infection.

Question 3

Which of the following statements about immunity in animals is INCORRECT?

Accepted Answer

A)  Invertebrates have no lymphocytes or truly specific immune responses. 
B)  Only vertebrates possess phagocytic cells. 
C)  Some invertebrates have antisomes that can distinguish its own cells from foreign material. 
D)  Most vertebrates have an immune system with antibodies, a spleen, thymus and T and B cells. 
E)  Multicellular invertebrates contain phagocytic cells that are able to engulf foreign material. 
A)  Invertebrates have no lymphocytes or truly specific immune responses. 
B)  Only vertebrates possess phagocytic cells. 
C)  Some invertebrates have antisomes that can distinguish its own cells from foreign material. 
D)  Most vertebrates have an immune system with antibodies, a spleen, thymus and T and B cells. 
E)  Multicellular invertebrates contain phagocytic cells that are able to engulf foreign material.

Question 4

A humoral immune response

Accepted Answer

A)  is mediated by soluble lymphokine molecules released by B cells into the serum or other body fluids. 
B)  is invoked principally in response to intracellular or viral infections. 
C)  depends on antibodies bound to cell membranes of B memory cells and B plasma cells. 
D)  is most effective against extracellular phases of bacterial and viral infections. 
E)  is induced against intracellular parasitic infections. 
A)  is mediated by soluble lymphokine molecules released by B cells into the serum or other body fluids. 
B)  is invoked principally in response to intracellular or viral infections. 
C)  depends on antibodies bound to cell membranes of B memory cells and B plasma cells. 
D)  is most effective against extracellular phases of bacterial and viral infections. 
E)  is induced against intracellular parasitic infections.

Question 5

In the human immune system, the consequences of the activation of the complement cascade include

Accepted Answer

A)  resistance to viral infection. 
B)  autoimmunity. 
C)  local inflammation, phagocytosis and bacterial lysis. 
D)  production of antigenic peptides. 
E)  establishment of acquired resistance. 
A)  resistance to viral infection. 
B)  autoimmunity. 
C)  local inflammation, phagocytosis and bacterial lysis. 
D)  production of antigenic peptides. 
E)  establishment of acquired resistance.

Question 6

The capacity of immune systems to protect against pathogens

Accepted Answer

A)  is a consequence of a small number of inherited genetic elements which are randomly rearranged during differentiation of specific immune cells. 
B)  is a consequence of a very large number of inherited genetic elements which produce individual lymphocytes carrying a distinct antigen receptor. 
C)  depends on mounting an inflammatory response at the site of infection. 
D)  is principally a function of the physical and chemical barriers and the action of phagocytic cells in conjunction with the complement system which prevent pathogens from becoming established. 
E)  depends on the effective screening of lymphocytes in the thymus, spleen and bone marrow to prevent the release of cells with receptors which can bind with molecules on the surfaces of self cells as if they were antigens. 
A)  is a consequence of a small number of inherited genetic elements which are randomly rearranged during differentiation of specific immune cells. 
B)  is a consequence of a very large number of inherited genetic elements which produce individual lymphocytes carrying a distinct antigen receptor. 
C)  depends on mounting an inflammatory response at the site of infection. 
D)  is principally a function of the physical and chemical barriers and the action of phagocytic cells in conjunction with the complement system which prevent pathogens from becoming established. 
E)  depends on the effective screening of lymphocytes in the thymus, spleen and bone marrow to prevent the release of cells with receptors which can bind with molecules on the surfaces of self cells as if they were antigens.

Question 7

Dendritic cells are

Accepted Answer

A)  the central cells of acquired immunity which specifically recognise different antigens. 
B)  non-specific effector cells which engulf and kill bacterial cells. 
C)  kill virus infected cells but not normal cells. 
D)  antigen-presenting cells which engulf and process antigen fragments of invading organisms. 
E)  cells which recognise antigen receptors anchored in their membranes. 
A)  the central cells of acquired immunity which specifically recognise different antigens. 
B)  non-specific effector cells which engulf and kill bacterial cells. 
C)  kill virus infected cells but not normal cells. 
D)  antigen-presenting cells which engulf and process antigen fragments of invading organisms. 
E)  cells which recognise antigen receptors anchored in their membranes.

Question 8

A secondary immunological response is

Accepted Answer

A)  generally slower and smaller than a primary response. 
B)  dependent on an immunological memory. 
C)  mounted against any type of pathogen so long as the immune system has previously mounted a primary response against any other pathogen. 
D)  dependent on the primary response activating the complement cascade. 
E)  absolutely specific. A secondary response cannot be mounted unless a primary response has already been elicited by the exact pathogen. 
A)  generally slower and smaller than a primary response. 
B)  dependent on an immunological memory. 
C)  mounted against any type of pathogen so long as the immune system has previously mounted a primary response against any other pathogen. 
D)  dependent on the primary response activating the complement cascade. 
E)  absolutely specific. A secondary response cannot be mounted unless a primary response has already been elicited by the exact pathogen.

Question 9

A sample of helper cells (TH) is being studied in the laboratory. When scientists present them with antigen in an attempt to stimulate the development of other immune system cells there is no affect. Why would this be?

Accepted Answer

A)  TC cells have not been processed in the thymus. 
B)  Macrophages lack a functional receptor. 
C)  The antigens have not been properly processed. 
D)  There are no antibodies present. 
E)  B cells have no activation binding site. 
A)  TC cells have not been processed in the thymus. 
B)  Macrophages lack a functional receptor. 
C)  The antigens have not been properly processed. 
D)  There are no antibodies present. 
E)  B cells have no activation binding site.

Question 10

Most fatal cancerous tumours are allowed to grow because

Accepted Answer

A)  the individual's immune system is not functioning properly. 
B)  they contain cells that are recognised as foreign by the immune system. 
C)  the immune system did not evolve to protect against tumours. 
D)  the cells are not immunogenic as they are recognised as self. 
E)  although tumours are immunogenic, they mainly occur in tissues and so are not accessible to lysis by TC cells. 
A)  the individual's immune system is not functioning properly. 
B)  they contain cells that are recognised as foreign by the immune system. 
C)  the immune system did not evolve to protect against tumours. 
D)  the cells are not immunogenic as they are recognised as self. 
E)  although tumours are immunogenic, they mainly occur in tissues and so are not accessible to lysis by TC cells.

Question 11

Immune responses to pathogens include the

Accepted Answer

A)  production of lysozymes in tears and saliva. 
B)  production of mucus in the respiratory and genital tracts. 
C)  production of immunoglobulins. 
D)  lowering of the pH in the stomach. 
E)  activation of the complement cascade. 
A)  production of lysozymes in tears and saliva. 
B)  production of mucus in the respiratory and genital tracts. 
C)  production of immunoglobulins. 
D)  lowering of the pH in the stomach. 
E)  activation of the complement cascade.

Question 12

The role of the immune system is to

Accepted Answer

A)  secrete enzymes that destroy microorganisms. 
B)  provide protection from pathogens such as viruses and bacteria. 
C)  produce natural antibiotics. 
D)  respond to parasite invasion and establish symbiosis. 
E)  All of the above are true. 
A)  secrete enzymes that destroy microorganisms. 
B)  provide protection from pathogens such as viruses and bacteria. 
C)  produce natural antibiotics. 
D)  respond to parasite invasion and establish symbiosis. 
E)  All of the above are true.

Question 13

An antibody is best described as

Accepted Answer

A)  glycoprotein produced in a cellular response to an immunogen. 
B)  protein molecule produced only by plasma cells in response to an antigen and which reacts specifically with that antigen. 
C)  the actual portion of an antigenic molecule that is recognised by a receptor. 
D)  glycoprotein molecule produced by B lymphocytes and plasma cells, in response to an immunogen. 
E)  a fundamentally important response to a pathogen found at all levels of animal life. 
A)  glycoprotein produced in a cellular response to an immunogen. 
B)  protein molecule produced only by plasma cells in response to an antigen and which reacts specifically with that antigen. 
C)  the actual portion of an antigenic molecule that is recognised by a receptor. 
D)  glycoprotein molecule produced by B lymphocytes and plasma cells, in response to an immunogen. 
E)  a fundamentally important response to a pathogen found at all levels of animal life.

Question 14

In plants

Accepted Answer

A)  immune defence is similar to that of invertebrates. 
B)  some species resemble mammals by having molecules coded by specific genes to be able to recognise particular pathogens. 
C)  immune mechanisms are local. 
D)  a circulatory system enables immune defence. 
E)  only the cell wall provides protection from invasion. 
A)  immune defence is similar to that of invertebrates. 
B)  some species resemble mammals by having molecules coded by specific genes to be able to recognise particular pathogens. 
C)  immune mechanisms are local. 
D)  a circulatory system enables immune defence. 
E)  only the cell wall provides protection from invasion.

Question 15

A scientist wants to create new dendrites in vitro. In order to do this, what would be the most differentiated cell he could use to create dendrites and where would he harvest them from?

Accepted Answer

A)  Myeloid progenitors from bone marrow 
B)  Lymphoid progenitors from the thymus 
C)  Multipotent progenitors from bone marrow 
D)  Lymphoid progenitors from bone marrow 
E)  Myeloid progenitors from the thymus 
A)  Myeloid progenitors from bone marrow 
B)  Lymphoid progenitors from the thymus 
C)  Multipotent progenitors from bone marrow 
D)  Lymphoid progenitors from bone marrow 
E)  Myeloid progenitors from the thymus

Question 16

In the human immune system, a difference between T-cell receptors and immunoglobulins is that T-cell receptors have

Accepted Answer

A)  twice as many binding sites. 
B)  more subtypes. 
C)  a larger degree of polymerisation. 
D)  only two polypeptide chains. 
E)  four polypeptide chains. 
A)  twice as many binding sites. 
B)  more subtypes. 
C)  a larger degree of polymerisation. 
D)  only two polypeptide chains. 
E)  four polypeptide chains.

Question 17

A primary response to infection in the mammalian immune system

Accepted Answer

A)  occurs on contact with a virus after immunisation. 
B)  happens once in the lifetime of an animal. 
C)  is not 'remembered' by the immune system. 
D)  occurs after first exposure to an antigen. 
E)  involves the complement cascade. 
A)  occurs on contact with a virus after immunisation. 
B)  happens once in the lifetime of an animal. 
C)  is not 'remembered' by the immune system. 
D)  occurs after first exposure to an antigen. 
E)  involves the complement cascade.

Question 18

Evolution of the immune system has resulted in a wide array of mechanisms of increasing complexity. Which of the following statements about the immune system is INCORRECT?

Accepted Answer

A)  Sea squids have small lymphocytes similar to those in mammals. 
B)  Some invertebrates produce antibody-like proteins which attach to non-self and aid clearance of the foreign material. 
C)  Birds have all the characteristics and functions of the immune system that mammals have. 
D)  The major secretory antigen IgA, which protects mucous membranes, is produced only in mammals. 
E)  Macrophages developed late in evolution, with fully active macrophages being found only in vertebrates. 
A)  Sea squids have small lymphocytes similar to those in mammals. 
B)  Some invertebrates produce antibody-like proteins which attach to non-self and aid clearance of the foreign material. 
C)  Birds have all the characteristics and functions of the immune system that mammals have. 
D)  The major secretory antigen IgA, which protects mucous membranes, is produced only in mammals. 
E)  Macrophages developed late in evolution, with fully active macrophages being found only in vertebrates.

Question 19

Interferons

Accepted Answer

A)  facilitate chemotaxis, opsonisation and lysis. 
B)  are glycoproteins produced by T lymphocytes in response to viral infections. 
C)  interfere with virus replication and production of viral proteins. 
D)  are part of the complement system. 
E)  are part of the innate response to bacterial infection. 
A)  facilitate chemotaxis, opsonisation and lysis. 
B)  are glycoproteins produced by T lymphocytes in response to viral infections. 
C)  interfere with virus replication and production of viral proteins. 
D)  are part of the complement system. 
E)  are part of the innate response to bacterial infection.

Question 20

Why are immune responses mediated by antibodies referred to as 'humoral immunity'?

Accepted Answer

A)  Because it is mediated by the humos 
B)  Because it involves H-cell recognition of foreign cells 
C)  Because they take place in the blood or humors 
D)  There is no such thing as humoral immunity 
E)  Because humoral is akin to holistic, denoting a systemic immune response which is uniform to all antibody responses 
A)  Because it is mediated by the humos 
B)  Because it involves H-cell recognition of foreign cells 
C)  Because they take place in the blood or humors 
D)  There is no such thing as humoral immunity 
E)  Because humoral is akin to holistic, denoting a systemic immune response which is uniform to all antibody responses

Exam 27: Innate Defences and the Immune System

Which of the following statements about the major histocompatibility complex (MHC) is true?

Phagocytes

Which of the following statements about immunity in animals is INCORRECT?

A humoral immune response

In the human immune system, the consequences of the activation of the complement cascade include

The capacity of immune systems to protect against pathogens

Dendritic cells are

A secondary immunological response is

A sample of helper cells (TH) is being studied in the laboratory. When scientists present them with antigen in an attempt to stimulate the development of other immune system cells there is no affect. Why would this be?

Most fatal cancerous tumours are allowed to grow because

Immune responses to pathogens include the

The role of the immune system is to

An antibody is best described as

In plants

A scientist wants to create new dendrites in vitro. In order to do this, what would be the most differentiated cell he could use to create dendrites and where would he harvest them from?

In the human immune system, a difference between T-cell receptors and immunoglobulins is that T-cell receptors have

A primary response to infection in the mammalian immune system

Evolution of the immune system has resulted in a wide array of mechanisms of increasing complexity. Which of the following statements about the immune system is INCORRECT?

Interferons

Why are immune responses mediated by antibodies referred to as 'humoral immunity'?

Nature of Molecules

Biomolecules

The Chemistry of Life

Functioning Cells

Movement Across Membranes

Harvesting Energy

Cells, Tissues and Signals

Cell Division

Inheritance

Genes, Chromosomes and Dna

The Genetic Code

Gene Expression

Genomes, Mutation and Cancer

Viruses

Genetic Engineering and Biotechnology

Reproduction, Growth and Development of Flowering Plants

Structure of Plants

Plant Nutrition, Transport and Adaptation to Stress

Plant Hormones and Growth Responses

Animal Reproduction

Animal Development

Homeostasis: Water, Solutes and Excretion

Gas Exchange in Animals

Circulation

Metabolism, Temperature Regulation and Environmental Stress

Animal and Human Nutrition

Hormonal Control in Animals

Nervous Systems

Animal Movement

Animal Behaviour

Evolving Life

Evolving Earth

Mechanisms of Evolution

Bacteria

The Protists

Plants

Fungi

Simple Animals: Sponges to Flatworms

Annelids, Molluscs, Nematodes and Arthropods

Echinoderms and Chordates

Australian Biota

Population Ecology

Living in Communities

Ecosystems

Human Impacts

Filters

A sample of helper cells (T_H) is being studied in the laboratory. When scientists present them with antigen in an attempt to stimulate the development of other immune system cells there is no affect. Why would this be?