Deck 48: The Immune System in Animals

Question 1

Which of the following statements about epitopes is FALSE?

A) There can be 10 or more different epitopes on each antigen.
B) T- cell receptors bind to epitopes.
C) B- cell receptors bind to epitopes.
D) There is a one- to- one correspondence between antigen and epitope.

Answer 1

D

Question 2

Mast cells can both constrict and dilate blood vessels after injury. Which of the following best explains why both of these events occur shortly after tissue is injured?

A) Mast cells release one chemical messenger immediately after injury that constricts vessels to promote clotting; after bleeding has stopped, they release another messenger that causes those same vessels to dilate, which increases blood flow to promote healing.
B) Mast cells release different chemical messengers, one that causes vessels away from the site of the injury to constrict to control blood loss, and another that causes vessels near the injury to dilate to promote quicker healing.
C) Mast cells release different chemical messengers, one that causes constriction in the region of blood loss, and another that causes dilation away from the injury to promote quicker healing.
D) Different blood vessels respond to the same messenger from mast cells in different ways-for example, larger vessels constrict to reduce blood loss while smaller ones dilate to promote blood flow to the injured tissue.

Answer 2

C

Question 3

Differences in the B- cell receptors of two different B cells are due to

A) the rearrangement of C- region genes in that clone of responsive B cells.
B) a switch in the kind of antigen- presenting cell that is involved in the immune response.
C) a patient's reaction to the first kind of antibody made by the plasma cells.
D) the recombination of variable regions of the light- chain and heavy- chain genes.
E) mutation in the genes of that B cell, induced by exposure to the antigen.

Answer 3

D

Question 4

You and a friend are in line for a movie when you notice the woman in front of you sneezing and coughing. Both of you have been equally exposed to the woman's virus, but over the next few days, only your friend acquires flu- like symptoms and is ill for almost a week before recovering. Which one of the following is a logical explanation for this?

A) You have an innate immunity to that virus.
B) You have an acquired immunity to that virus.
C) Your friend does not have the ability to fight off that particular virus.
D) Answers B and C are both correct.

Question 5

A newborn who is accidentally given a drug that destroys the thymus would most likely

A) have a reduced number of B cells and be unable to form antibodies.
B) lack innate immunity.
C) lack class I major histocompatability MHC) molecules on cell surfaces.
D) be unable to differentiate and mature T cells.
E) be unable to genetically rearrange antigen receptors.

Question 6

It is commonly know that breast milk provides many benefits to a newborn baby because it provides immune benefits. Which of the following immunoglobulins play a role in this?

A) IgA
B) IgG
C) IgE
D) IgM

Question 7

A small child falls down and cuts his knee. A few days later a scab forms over the wound. After a few weeks, the wound does not appear to be healing, but it is not infected. Which of the following could explain this?

A) The child has a platelet deficiency.
B) The child has a mast cell deficiency.
C) The child has a cytokine deficiency.
D) The child has a neutrophile deficiency.
E) Answers C or D are possible.

Question 8

Mucous occurs in both the respiratory and digestive tracts. What is its main immunological function?

A) physically trapping pathogens
B) sweeping away debris
C) increasing oxygen absorption
D) destruction of pathogens because it is acidic

Question 9

Which of the following pairs of proteins shares the most overall similarity in structure?

A) T- cell receptors and antibodies
B) B- cell receptors and antibodies
C) B- cell receptors and T- cell receptors
D) antibodies and antigens

Question 10

Lymphocytes are formed in what organs)?

A) spleen
B) thymus
C) bone marrow
D) both A and C
E) both B and C

Question 11

Which of the following would put you at increased risk of pathogens entering your body?

A) a mutation preventing you from making lysozyme
B) cleaning the wax out of your ears on a daily basis
C) a mutation that causes your mucus secretions to be extremely watery
D) all of the above
E) A and C only

Question 12

Which of the following best describes what an antigen is?

A) a protein in the immune system that is used to identify potential pathogens
B) a molecule, such as a polypeptide or carbohydrate, that initiates a response from the immune system
C) a molecule that is used during an immune response to enhance the binding of antibodies to damaged cells
D) all of the above

Question 13

Arrange in the correct sequence each of the following components of the mammalian immune system as it first responds to a pathogen.
I. Pathogen is destroyed.
II. Lymphocytes secrete antibodies.
III. Antigens from the pathogen bind to receptors on lymphocytes.
IV. Lymphocytes specific to antigens from the pathogen become numerous.
V. Only memory cells remain.

A) III -II -I -V -IV
B) I -III -II -IV - V
C) IV -II -III -I - V
D) II -I -IV -III - V
E) III -IV -II -I -V

Question 14

If you were developing artificial B- cell receptors BCRs) based on the natural version and wanted to change the BCRs' ability to bind certain antigens, which region of the natural receptor would you alter?

A) carboxy terminus of light and heavy chains
B) amino terminus of light and heavy chains
C) transmembrane domain
D) the region projecting into the cytoplasm of the cell

Question 15

What do neutrophils and macrophages have in common?

A) Both arrive simultaneously at a wound site.
B) Both ingest and kill bacteria.
C) Both secrete lysozymes.
D) Both secrete cytokines.

Question 16

What major advantage is conveyed by having a system of acquired immunity?

A) It enables a rapid defence against an antigen that has been previously encountered.
B) It enables an animal to counter most pathogens almost instantly.
C) It allows for extremely precise specificity for defence against antigens.
D) All of the above answers are correct.
E) Answers A and C are both correct.

Question 17

You cut your finger, and after putting pressure on the wound for several minutes, you notice that it is still bleeding profusely. What may be the problem?

A) Platelets are not functioning properly, or there are too few to be effective.
B) Mast cells are not releasing their chemical messengers.
C) There are too many antigens to allow clotting.
D) Answers A and B are both correct.
E) Answers B and C are both correct.

Question 18

You are playing a new video game that is based on the human immune system. The player is inside a human, and you must successfully fend off invading pathogens in a quest to find the "Golden Antibody." At level 1, your arsenal for fighting off pathogens consists only of the innate immunity leukocytes and their various secretions. If the enemy has killed off most of your neutrophils and macrophages, which of the following should you utilize to recruit more of these leukocytes to the battle?

A) bone marrow
B) reactive oxygen species
C) platelets
D) cytokines
E) histamine

Question 19

Which of the following is the best definition of autoimmune disease?

A) a condition in which B cells and T cells respond independently to antigens and do not interact correctly
B) a condition in which a molecule belonging to the host is treated like an antigen and triggers an immune response
C) a condition in which the acquired immune system fails to recognize the second infection by the same antigen
D) a condition in which the immune system creates random antibodies without being triggered by an antigen

Question 20

Which of the following statements is not fundamental to the clonal- selection theory of how the acquired immune system functions?

A) Each lymphocyte has a unique membrane receptor that recognizes one antigen.
B) Cloned cells descend from an activated lymphocyte and persist even after the pathogen is eliminated.
C) When the lymphocyte binds an antigen, it is activated and begins dividing to form many identical copies of itself.
D) Cloned lymphocytes have slight differences and are selected by the spleen for removal if they do not bind an antigen.

Question 21

Which of the following statements are fundamental to the clonal- selection theory of how the adaptive immune system functions?
I. Each mature lymphocyte has a unique membrane receptor that recognizes one antigen.
II. When the lymphocyte binds an antigen, the lymphocyte is activated and begins dividing to form many ident copies of itself.
III. Cloned lymphocytes have slight differences and are selected by the spleen for removal if they do not bind an antigen.
IV. Cloned cells descend from an activated lymphocyte and persist even after the pathogen is eliminated.

A) only I, II, and IV
B) only II and IV
C) only I and III
D) only II, III, and IV
E) I, II, III, and IV

Question 22

Which of the following is a difference between Class I and Class II major histocompatibility complex MHC) proteins?

A) Class I MHC proteins can be found on most cell types and signals that this cell has been compromised, while Class II proteins are found on cells of the immune system and are designed to activate immune responses.
B) Class I MHC proteins are added to antigens in the cytoplasm, while Class II proteins are added to antigens in the Golgi apparatus.
C) Class I and Class II MHC proteins have the same basic role, but individuals with particularly strong immune systems will have both types while most individuals have just one or the other.
D) Class I MHC proteins signal the immune system to activate the cell displaying the message, while Class II proteins signal the immune system to destroy a particular cell.

Question 23

If a patient is missing B and T cells, what would be absent from the immune response?

A) lysozymes
B) memory
C) the innate immune response
D) cytokines
E) defence against bacteria

Question 24

Although the number of major histocompatibility MHC) protein isoforms possible in a given human population is enormous, why does each individual have a limited array of MHC molecules?

A) because once a B cell has matured in the bone marrow, it is limited to two MHC response categories
B) because each of the MHC genes has a large number of alleles, but each individual inherits only two for each gene
C) because once a T cell has matured in the thymus, it can only respond to two MHC categories
D) because the MHC proteins are made from several different gene regions that are capable of rearranging in a number of ways
E) because the MHC proteins from one individual can only be of class I or class II

Question 25

A certain cell type has existed in the blood and tissue of its vertebrate host's immune system for over 20 years. One day, it recognizes a newly arrived antigen and binds to it, subsequently triggering a secondary immune response in the body. Which of the following cell types most accurately describes this cell?

A) T cell
B) memory cell
C) secondary cell
D) B cell

Question 26

Which of the following is a difference between a primary and a secondary immune response?

A) The secondary response comes immediately after the primary response.
B) The primary response generates an allergy, which the body uses in the secondary response.
C) The secondary response involves memory cells, the primary does not.
D) The primary response involves immunological memory whereas the secondary response does not.

Question 27

What causes rejection by the body's immune system after a transplant of an improperly matched organ?

A) non- self proteins in the tissue
B) the presence of foreign MHC proteins on the donor tissue
C) antibodies and cytotoxic T lymphocytes CTLs) responding to foreign tissue
D) all of the above
E) A and C only

Question 28

Your sister- in- law never gets sick, while her male neighbour seems to be sick all the time. Although there are several explanations for this, one is that they are genetically different. Which of the following hypotheses concerning genetic inheritance of major histocompatibility complex MHC) is consistent with this observation and your understanding of the immune system as described in the text?

A) In the case of MHC, it is beneficial to have as many different alleles as possible, so heterozygous individuals are healthier than homozygous dominant or recessive individuals.
B) MHC inheritance works like normal Mendelian genetics in the sense that there are dominant traits and recessive traits, and in the case of MHC, those with the dominant trait including both those who are heterozygous and homozygous dominant) produce more normal MHC proteins and are healthier than those with the recessive trait homozygous recessive).
C) MHC proteins are often closely associated with small antigen particles that have been broken off the main pathogen, so that individuals who are recessive for MHC don't normally have many illnesses because they don't produce these MHC- antigen complexes.
D) MHC inheritance is X- linked and thus males will have a higher percentage of weak immune systems than females do.

Question 29

Home blood typing kits reveal an individual's blood type by interpreting how blood reacts when exposed to antibodies. Which of the following is studied to interpret the results using these types of kits?

A) autoimmunity
B) agglutination
C) hypersensitivity
D) complementation

Question 30

Which of the following components of the immune system destroys bacteria in a way similar to an antitank weapon destroying armored military tanks by punching holes in the wall of the bacteria?

A) major histocompatibility complex proteins
B) plasma cells
C) macrophages
D) complement protein

Question 31

Which of the following is crucial to activation of the acquired immune response?

A) memory cells
B) presentation of MHC- antigen complex on a cell surface
C) phagocytosis of antibody- antigen complex by macrophages in the blood the humoral response)
D) somatic hypermutation

Question 32

Which of the following is true of the allergic response?

A) It is a normal, healthy, adaptive response to an allergen.
B) Upon the very first exposure to an allergen, an allergy sufferer will probably experience a runny nose, watery eyes, and mild wheezing.
C) Sufferers produce the IgE class of gamma globulins in response to allergens.
D) All of the above answers are true.

Question 33

Which of the following is a difference between B cells and T cells?

A) One has a major role in antibody production, while the other has a major role in cytotoxicity.
B) One uses a receptor called BCR, while the other recognizes a receptor called TCR.
C) One is activated by membrane bound antigens, while the other is activated by free- floating antigens in blood or lymph.
D) All of the above are differences.
E) Only A and B are differences.

Question 34

Which of the following is true of the humoral immune response and NOT true of the cell- mediated immune response?

A) require CD8⁺ cells for activation
B) involves T cells at some level
C) involves destroying entire cells and not just the pathogen
D) uses antibodies as its main weapon
E) All of these answers are true of the humoral immune response and not true of the cell- mediated immune response.

Question 35

All of the following are differences between a B- cell receptor and an antibody produced by a B- cell EXCEPT that

A) B- cell receptors belong to the immunoglobulin protein family while antibodies produced by B- cells do not.
B) B- cells receptors have transmembrane domains while antibodies produced by B- cells do not.
C) B- cell receptors are inserted into the plasma membrane while antibodies produced by B- cells are secreted.

Question 36

Which of the following are effective treatments for some allergic reactions?

A) antihistamines
B) epinephrine
C) corticosteroids
D) all of the above
E) both A and B

Question 37

What is the difference between a secondary immune response occurring without a vaccine compared to the same response occurring after a vaccine?

A) A person who has received a vaccine does not have a secondary response, while someone without a vaccine does.
B) A person who has received a vaccine may have a secondary immune response on the first exposure to the normal, living pathogen.
C) Even with a vaccine, someone must still go through development of memory cells before they can have a secondary response.
D) All of the above answers apply.
E) Only answers B and C apply.

Question 38

What would be the consequences) of a mutation that did not allow for selection against self- responding lymphocytes those that respond against self)?

A) The immune system would fail and the individual would catch many illnesses.
B) The lymphocytes would be more likely to recognize antigens they had previously been exposed to.
C) This would likely be a fatal condition as the lymphocytes would attack all self cells.