Question 1

In the human immune system, each antibody molecule consists of four polypeptide chains. Which of the following statements about these chains is CORRECT?

Accepted Answer

A)  There are two identical heavy and two identical light chains. 
B)  Each chain has two different binding sites at its end. 
C)  Only the heavy chains have a variable region. 
D)  Epitopes are attached to the ends of the chains. 
E)  The antigen binding site is formed by the dimerisation of an $\alpha$ and a $\beta$chain polypeptide. 
A)  There are two identical heavy and two identical light chains. 
B)  Each chain has two different binding sites at its end. 
C)  Only the heavy chains have a variable region. 
D)  Epitopes are attached to the ends of the chains. 
E)  The antigen binding site is formed by the dimerisation of an $\alpha$ and a $\beta$chain polypeptide. A

Question 2

A fundamental requirement of any immune defence system is its ability to distinguish between _______ and ________.

Accepted Answer

A)  antibodies; antigens. 
B)  bacteria; viruses. 
C)  internal; external. 
D)  self; non-self. 
E)  erythrocytes; leukocytes. 
A)  antibodies; antigens. 
B)  bacteria; viruses. 
C)  internal; external. 
D)  self; non-self. 
E)  erythrocytes; leukocytes. D

Question 3

Complement is

Accepted Answer

A)  a series of about 20 proteins in mammals which interact to lyse membranes of some organisms. 
B)  a form of self-recognition which helps distinguish self from non-self. 
C)  a major arm of the defence mechanism of Chordates. 
D)  central to a specific immune response due to their ability to cause antibody production. 
E)  a transmembrane protein which is a primitive recognition molecule which when stimulated secretes defence peptides. 
A)  a series of about 20 proteins in mammals which interact to lyse membranes of some organisms. 
B)  a form of self-recognition which helps distinguish self from non-self. 
C)  a major arm of the defence mechanism of Chordates. 
D)  central to a specific immune response due to their ability to cause antibody production. 
E)  a transmembrane protein which is a primitive recognition molecule which when stimulated secretes defence peptides. A

Question 4

Allergenic responses occur because of:

Accepted Answer

A)  infection through the epithelial surfaces. 
B)  IgE binding to the surface of mast cells. 
C)  proliferation of TC cells. 
D)  the cascade of the complement system. 
E)  activation of B cells by antigen, inducing secretion of antibodies and histamines. 
A)  infection through the epithelial surfaces. 
B)  IgE binding to the surface of mast cells. 
C)  proliferation of TC cells. 
D)  the cascade of the complement system. 
E)  activation of B cells by antigen, inducing secretion of antibodies and histamines.

Question 5

When an immature T-cell enters the thymus, there is a rearrangement of genes coding for the T-cell receptor. What immune protein produced by B lymphocytes undergoes an analogous development?

Accepted Answer

A)  alpha-amylase. 
B)  beta-glucanase. 
C)  Phenylalanine lyase. 
D)  Major histocompatibility complex. 
E)  Immunoglobulin. 
A)  alpha-amylase. 
B)  beta-glucanase. 
C)  Phenylalanine lyase. 
D)  Major histocompatibility complex. 
E)  Immunoglobulin.

Question 6

Which of the following statements is false?

Accepted Answer

A)  Antibodies are the result of random genetic rearrangement. 
B)  Antibodies provide non-specific immunoprotection. 
C)  Antibodies are protein molecules. 
D)  Antibodies are the basis of acquired immunity. 
E)  Antibodies are produced by lymphocytes. 
A)  Antibodies are the result of random genetic rearrangement. 
B)  Antibodies provide non-specific immunoprotection. 
C)  Antibodies are protein molecules. 
D)  Antibodies are the basis of acquired immunity. 
E)  Antibodies are produced by lymphocytes.

Question 7

Immunogens

Accepted Answer

A)  are peptides of up to ten amino acids, which are the largest molecules capable of binding directly with TCRs or antibodies. 
B)  are capable of being bound by antibodies directly without the mediation of major histocompatibility (MH
C)  proteins. 
C)  are recognised by TCRs only when presented complexed with the MHC molecules of phagocytes. The MHC molecules are only capable of presenting epitopes that were on the surface of the intact molecule. 
D)  to which T cells respond are of a wide variety and include carbohydrates and proteins. B cells only respond to protein immunogens. 
E)  are antibodies produced in response to a foreign organism. 
A)  are peptides of up to ten amino acids, which are the largest molecules capable of binding directly with TCRs or antibodies. 
B)  are capable of being bound by antibodies directly without the mediation of major histocompatibility (MH
C)  proteins. 
C)  are recognised by TCRs only when presented complexed with the MHC molecules of phagocytes. The MHC molecules are only capable of presenting epitopes that were on the surface of the intact molecule. 
D)  to which T cells respond are of a wide variety and include carbohydrates and proteins. B cells only respond to protein immunogens. 
E)  are antibodies produced in response to a foreign organism.

Question 8

A form of non-specific defence against infection is

Accepted Answer

A)  the complement system. 
B)  interferons. 
C)  lysozymes. 
D)  cytokines. 
E)  All of the answers are forms of non-specific defence against infection. 
A)  the complement system. 
B)  interferons. 
C)  lysozymes. 
D)  cytokines. 
E)  All of the answers are forms of non-specific defence against infection.

Question 9

Which cell of the immune system has similar morphology to classical lymphocytes, but lacks the same specificity?

Accepted Answer

A)  B lymphocyte 
B)  Natural Killer (NT) cells 
C)  T cell 
D)  Monocyte 
E)  Granulocyte 
A)  B lymphocyte 
B)  Natural Killer (NT) cells 
C)  T cell 
D)  Monocyte 
E)  Granulocyte

Question 10

An epitope is best defined as

Accepted Answer

A)  the actual portion of an antigenic molecule that is recognised by a receptor. 
B)  an antigen which precipitates an immune response by inducing the production of antibodies or T-cell receptors. 
C)  any molecule which can be recognised by one of the specific molecules of the immune system. 
D)  the interacting protein in the complement cascade. 
E)  an immunogen. 
A)  the actual portion of an antigenic molecule that is recognised by a receptor. 
B)  an antigen which precipitates an immune response by inducing the production of antibodies or T-cell receptors. 
C)  any molecule which can be recognised by one of the specific molecules of the immune system. 
D)  the interacting protein in the complement cascade. 
E)  an immunogen.

Question 11

Which immune cell regulates the activation of the killing capacity of macrophages?

Accepted Answer

A)  Plasma cell 
B)  Granulocyte 
C)  NK cells 
D)  T-cells 
E)  B lymphocytes 
A)  Plasma cell 
B)  Granulocyte 
C)  NK cells 
D)  T-cells 
E)  B lymphocytes

Question 12

The theory of clonal selection in immune responses suggests that

Accepted Answer

A)  cells interacting with antigens will proliferate. 
B)  infants receive their immune-specific lymphocytes from their mother. 
C)  the pre-immune response produces a large number of genetically identical lymphocytes. 
D)  lymphocytes will rearrange their surface molecules. 
E)  clones of cells expressing the TCR (T-cell receptor) will multiply and interact with an organism to kill it. 
A)  cells interacting with antigens will proliferate. 
B)  infants receive their immune-specific lymphocytes from their mother. 
C)  the pre-immune response produces a large number of genetically identical lymphocytes. 
D)  lymphocytes will rearrange their surface molecules. 
E)  clones of cells expressing the TCR (T-cell receptor) will multiply and interact with an organism to kill it.

Question 13

In what organ to B cells develop in birds?

Accepted Answer

A)  Bone marrow 
B)  Brain 
C)  Brique de loopus 
D)  Bursa of Fabricius 
E)  Basal ganglion 
A)  Bone marrow 
B)  Brain 
C)  Brique de loopus 
D)  Bursa of Fabricius 
E)  Basal ganglion

Question 14

If a pathogen passes the initial external defences and invades the body

Accepted Answer

A)  internal specific defence mechanisms are activated. 
B)  interleukin-2 is produced by natural killer cells to expand the initial response. 
C)  monocytes release perforins which punch holes in the membranes of infected cells. 
D)  phagocytic cells engulf particles and kill the invading organisms. 
E)  macrophages are attracted to the site of infection and activate the complement cascade. 
A)  internal specific defence mechanisms are activated. 
B)  interleukin-2 is produced by natural killer cells to expand the initial response. 
C)  monocytes release perforins which punch holes in the membranes of infected cells. 
D)  phagocytic cells engulf particles and kill the invading organisms. 
E)  macrophages are attracted to the site of infection and activate the complement cascade.

Question 15

During an immune response any lymphocyte that encounters its specific antigen

Accepted Answer

A)  binds with it precipitating a series of complex rearrangement events involving variable (V) genes, diversity (
D)  and joining (J) elements but not constant (
C)  genes. 
B)  undergoes a series of complex rearrangement events involving variable (V) and constant (
C)  genes together with diversity (
D)  and joining (J) elements. 
C)  will not bind with it in the absence of complement proteins failing to opsonise the pathogen. 
D)  will secrete antibodies specific to the antigen and neutralise it. 
E)  will undergo clonal selection. 
A)  binds with it precipitating a series of complex rearrangement events involving variable (V) genes, diversity (
D)  and joining (J) elements but not constant (
C)  genes. 
B)  undergoes a series of complex rearrangement events involving variable (V) and constant (
C)  genes together with diversity (
D)  and joining (J) elements. 
C)  will not bind with it in the absence of complement proteins failing to opsonise the pathogen. 
D)  will secrete antibodies specific to the antigen and neutralise it. 
E)  will undergo clonal selection.

Question 16

Immunological tolerance

Accepted Answer

A)  describes the response mounted against a pathogen where an immunological memory already exists. 
B)  precipitates an autoimmune response with debilitating consequences and is dysfunctional. 
C)  is best treated with anti-inflammatory or immunosuppressive drugs rather than antihistamines. 
D)  occurs in mature lymphocytes where interaction with self antigens causes cellular damage resulting in disease. 
E)  develops at an early stage and is critical to the effective operation of a normal immune system. 
A)  describes the response mounted against a pathogen where an immunological memory already exists. 
B)  precipitates an autoimmune response with debilitating consequences and is dysfunctional. 
C)  is best treated with anti-inflammatory or immunosuppressive drugs rather than antihistamines. 
D)  occurs in mature lymphocytes where interaction with self antigens causes cellular damage resulting in disease. 
E)  develops at an early stage and is critical to the effective operation of a normal immune system.

Question 17

T-cell receptors (TCR) and Immunoglobulins (Ig) are glycoproteins that recognise specific antigens. Their structure and function is similar for both EXCEPT

Accepted Answer

A)  they are dimers of two different polypeptides 
B)  they are synthesised by the rearrangement of several, similar gene segments. 
C)  they are composed of a variable epitope that contributes to the antigen binding site. 
D)  they interact with antigen to produce proliferation and differentiation of T-cells. 
E)  they are membrane-bound molecules on the surface of the lymphocyte. 
A)  they are dimers of two different polypeptides 
B)  they are synthesised by the rearrangement of several, similar gene segments. 
C)  they are composed of a variable epitope that contributes to the antigen binding site. 
D)  they interact with antigen to produce proliferation and differentiation of T-cells. 
E)  they are membrane-bound molecules on the surface of the lymphocyte.

Question 18

In the human immune system

Accepted Answer

A)  an immunogen is the variable region of an immunoglobulin molecule. 
B)  an immunogen is an antigen which stimulates lymphocytes to make an immune response. 
C)  antibodies will respond to polypeptide fragments of three or more amino acids. 
D)  epitopes are produced during an autoimmune response. 
E)  immunological memory results from activation of specific epitopes produced in response to infection. 
A)  an immunogen is the variable region of an immunoglobulin molecule. 
B)  an immunogen is an antigen which stimulates lymphocytes to make an immune response. 
C)  antibodies will respond to polypeptide fragments of three or more amino acids. 
D)  epitopes are produced during an autoimmune response. 
E)  immunological memory results from activation of specific epitopes produced in response to infection.

Question 19

T lymphocytes

Accepted Answer

A)  mature in the spleen and if the spleen is absent or removed early in fetal development no T cells are produced and profound immunodeficiency results. 
B)  fall into two functionally distinct classes, helper cells and cytotoxic cells, which secrete lymphokines. 
C)  have TCR (T-cell receptors) which are functional only when bound to the membranes of helper cells and cytotoxic cells. 
D)  are essential to primary immunity. 
E)  are screened in the spleen but mature in the bone marrow. 
A)  mature in the spleen and if the spleen is absent or removed early in fetal development no T cells are produced and profound immunodeficiency results. 
B)  fall into two functionally distinct classes, helper cells and cytotoxic cells, which secrete lymphokines. 
C)  have TCR (T-cell receptors) which are functional only when bound to the membranes of helper cells and cytotoxic cells. 
D)  are essential to primary immunity. 
E)  are screened in the spleen but mature in the bone marrow.

Question 20

An antigen is best defined as

Accepted Answer

A)  a foreign organic molecule recognised and bound by T-cell receptors or antibodies. 
B)  the actual portion of a molecule which elicits a specific immune response. 
C)  an immunogen. 
D)  a membrane protein of a bacterium which interacts with a B-cell to cause lysis. 
E)  any molecule which can be recognised by one of the specific molecules of the immune system. 
A)  a foreign organic molecule recognised and bound by T-cell receptors or antibodies. 
B)  the actual portion of a molecule which elicits a specific immune response. 
C)  an immunogen. 
D)  a membrane protein of a bacterium which interacts with a B-cell to cause lysis. 
E)  any molecule which can be recognised by one of the specific molecules of the immune system.

Exam 27: Innate Defences and the Immune System

In the human immune system, each antibody molecule consists of four polypeptide chains. Which of the following statements about these chains is CORRECT?

A fundamental requirement of any immune defence system is its ability to distinguish between _______ and ________.

Complement is

Allergenic responses occur because of:

When an immature T-cell enters the thymus, there is a rearrangement of genes coding for the T-cell receptor. What immune protein produced by B lymphocytes undergoes an analogous development?

Which of the following statements is false?

Immunogens

A form of non-specific defence against infection is

Which cell of the immune system has similar morphology to classical lymphocytes, but lacks the same specificity?

An epitope is best defined as

Which immune cell regulates the activation of the killing capacity of macrophages?

The theory of clonal selection in immune responses suggests that

In what organ to B cells develop in birds?

If a pathogen passes the initial external defences and invades the body

During an immune response any lymphocyte that encounters its specific antigen

Immunological tolerance

T-cell receptors (TCR) and Immunoglobulins (Ig) are glycoproteins that recognise specific antigens. Their structure and function is similar for both EXCEPT

In the human immune system

T lymphocytes

An antigen is best defined as

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 fundamental requirement of any immune defence system is its ability to distinguish between _ and __.