Deck 1: Overview of the Immune System

Question 1

Two of the main, early theories proposed to explain how antigen-specific antibodies develop were the instructional theory and the selective theory.How did the two differ? Which was ultimately shown to be CORRECT?

Answer 1

The selective theory says that, when an antigen receptor binds with an antigen, the cell becomes activated (or the cell is selected to proliferate and secrete more copies of the receptor).The instructional theory says that the antigen receptor molds itself to the antigen.The selective theory was shown to be correct.

Question 2

Often, serendipity plays a role in significant scientific discoveries.In your own words, explain how serendipity led Pasteur to discover a cholera vaccine.

Answer 2

Pasteur developed the vaccine in chickens, which were in short supply.He challenged groups of chickens with cholera bacteria - some of which were previously exposed to an attenuated version of cholera bacteria.Only the previously exposed animals were protected from a new challenge, which led to the use of weakened pathogens as vaccines.

Question 3

Despite its having been eradicated on a global scale, smallpox is presently considered a potential bioterrorism threat.Why? Use evidence to support your answer.

Answer 3

After eradication was achieved, smallpox vaccination programs largely ended.As populations continued to grow over time, an ever-increasing percentage of the human population remains unvaccinated and thus, is still susceptible to the disease.

Question 4

Prior to 1999, it was claimed that a thimerosal additive in vaccines was contributing to the rising incidence of autism.If the claims were true, what resultant trend might you expect to observe in the rate of autism once thimerosal was removed from vaccines?

Question 5

Given the discovery and development of effective antibiotics, make an argument for the continued use of vaccines against bacterial pathogens.Use evidence to support your answer.

Question 6

You have a friend unfamiliar with immunology, and he asks you the following question: "Why do I need the flu shot every year, but don't need an annual chickenpox vaccine?" As a student of immunology, how would you explain this discrepancy to your friend? Use evidence to support your answer.

Question 7

Provide one benefit and one drawback of generating random recognition receptors during the development of B cells.

Question 8

A portion of our immune systems' white blood cells is constantly circulating throughout the body via circulation and lymphatics.What is the benefit of such circulation?

Question 9

Complete the following table by comparing and contrasting innate and adaptive immune responses.

Question 10

What are the hallmarks of inflammation? Describe the physical characteristics of someone experiencing an inflammatory response.

Question 11

Upon receiving immune serum as a treatment for a venomous snake bite, would the recipient be immune from future bites of the same species?

Question 12

Provide one common feature of and two differences between B-cell receptors and PRRs.

Question 13

Given that an important function of the immune system is to both recognize and dispose of cancerous cells, postulate why tumors can be established in a human host.

Question 14

The hygiene hypothesis posits that there is a connection between environmental conditions and certain inappropriate immune responses.If you were a supporter of the hygiene hypothesis, what recommendations would you make to keep people healthier?

Question 15

Which is the BEST definition of "immunity"?

A)The state of having been exposed to a pathogen repeatedly
B)The state of being resistant to reinfection with a pathogen
C)When an individual has never been exposed to a pathogen
D)When the immune system is activated
E)When physical barriers are not enough to prevent infection

Question 16

What happens to a pathogen as it becomes attenuated?

A)It becomes more dangerous to the host.
B)It gets smaller.
C)It has weakened virulence.
D)It becomes older.
E)All of the answers are correct.

Question 17

Which of the following advances can be credited to progress made in our understanding of immunology?

A)Smallpox eradication
B)Treatment of asthma
C)Ability to transplant human organs
D)Cancer treatment
E)All of the answers are correct.

Question 18

Which of the following is the BEST example of herd immunity?

A)A child infected with measles travels from Germany to the United States.Several babies contract the disease, but the outbreak is largely contained due to vaccinations.
B)Certain populations of cattle are less susceptible to infection with encephalitis because of their genetic makeup.
C)Once a certain threshold of individuals has been infected with a novel human pathogen, it is unlikely that any more will be.
D)Geese and chickens are infected with different strains of influenza because they express different receptors on their cell surface.
E)When infection spreads through a population, certain individuals generate stronger immune responses than others.

Question 19

Which of the following diseases does NOT currently have an effective vaccine?

A)Chicken pox
B)Polio
C)HIV
D)Smallpox
E)Diptheria

Question 20

Examine Figure 1-8.Which cells are MOST likely responsible for the intense response to Antigen A following a second exposure?
​

A)B cells
B)T cells
C)Memory T cells
D)Memory B cells
E)Both memory T cells and memory B cells are responsible.

Question 21

Effectors of the humoral immune system are known as

A)antibodies.
B)immunoglobulin.
C)complement.
D)B cells.
E)All of the answers are correct.

Question 22

Which of the following cell types are lymphocytes?

A)Macrophages
B)Mast cells
C)Neutrophils
D)Erythrocytes
E)T cells

Question 23

Which of the following is TRUE about antigens?

A)They are always derived from pathogens.
B)They are always proteins.
C)They are recognized by T cells or B cells.
D)They must be microbial in origin.
E)They usually cause cellular damage.

Question 24

Which of the following is a fungal pathogen?

A)Vibrio cholera
B)Leishmania major
C)Poliovirus
D)Candida albicans
E)Bordetella pertussis

Question 25

Overall, the human immune system views microbes as pathogens.

Question 26

Which of the following factors has been shown as potentially impacting immune homeostasis in favor of inflammation?

A)Diet
B)Stress
C)Microbiome composition
D)All of the answers are correct.
E)None of the answers are correct.

Question 27

Many of the ideas raised by Ehrlich's conception of selective theory were true.Which of the following ideas (if any) were later shown to be FALSE?

A)Interaction between a cell-bound receptor and pathogen could induce the cell to proliferate.
B)The specificity of receptors was determined in the host prior to exposure to a foreign antigen.
C)The antigen selected the appropriate receptor in a specific manner.
D)The binding of a receptor to an infectious agent was like the fit between a lock and a key.
E)All the ideas listed were shown to be true.

Question 28

Which of the following cell types is MOST commonly associated with recognizing antigens found inside of cells?

A)Macrophages
B)B cells
C)T_H cells
D)CTLs
E)Antibodies

Question 29

Which of the following classes of cell surface receptors are directly encoded in the germ line?

A)TCR
B)BCR
C)PRR
D)Antibodies
E)All of the answers are correct.

Question 30

What is the central mechanism for establishing self-tolerance?

A)Self-reactive T cells and B cells are killed during development.
B)Individuals that have immune systems that respond to self-antigens do not survive to reproduce.
C)Immune cells that react to self-antigens are turned off when they recognize self-tissues.
D)Certain immune suppressive cytokines are maintained in tissues to dampen auto reactive immune responses.
E)Peripheral tissues have mechanisms to kill T or B cells that respond to them.

Question 31

Which of the following BEST describes chemokines?

A)Membrane receptors that detect the presence of soluble messengers in the environment
B)Soluble proteins that recruit specific cells to an area
C)Chemical messengers that induce cell differentiation
D)Transcription factors that induce the expression of genes involved in cell adhesion
E)Adhesion molecules that bind to the inside of blood vessels

Question 32

Which of the following statements BEST differentiates innate and adaptive immune responses?

A)Innate responses are stronger during the primary and less important during the secondary response, whereas adaptive responses are less robust during primary responses and stronger during secondary responses.
B)Innate responses are weaker during the primary and more robust during the secondary response, whereas adaptive responses are stronger during the primary and weaker during secondary responses.
C)Innate responses are slower and weaker than adaptive responses.
D)Adaptive responses are slower and weaker than innate responses.
E)Adaptive responses are required for effective immune responses, whereas innate responses are not required.

Question 33

The innate and adaptive immune responses work largely independently of one another.

Question 34

How do memory cells develop?

A)Upon reinfection, memory centers in the brain send signals to the bone marrow to induce T-cell and B-cell differentiation.
B)T cells and B cells from the primary response persist and become reactivated.
C)Innate cells are trained to activate new T cells and B cells more quickly with secondary infection.
D)T cells and B cells from the primary infection slowly mutate their receptors over time, priming themselves for the secondary response.
E)Innate cells modify their cell surface receptors to prepare for reinfection.

Question 35

Which of the following is the BEST example of a hypersensitivity reaction?

A)T cells responding vigorously to the flu virus
B)B cells failing to respond to HIV, allowing it to replicate out of control
C)Inflammation of the airways in response to pollen
D)Anemia as a result of iron deficiency
E)T cells attacking the myelin sheath of nerves resulting in paralysis

Question 36

HIV disease is a(an)

A)autoimmune disease.
B)hypersensitivity disease.
C)immunodeficiency.
D)genetic disorder.
E)allergic reaction.

Question 37

Predict the outcome of being immunosuppressed as it relates to the development of cancer.

A)Immunosuppressed individuals are at lower risk of cancer because cytokines produced by the immune system induce cancer.
B)Immunosuppressed individuals are at lower risk of cancer because they are more likely to contract infectious diseases.
C)Immunosuppressed individuals are at higher risk of cancer because the immune system recognizes and destroys cancerous cells.
D)Immunosuppressed individuals are at higher risk of cancer because they bear a higher load of microbes that damage host tissues.
E)None of the answers are correct.

Question 38

What occurs when someone receives a tissue transplant from an unrelated individual?

A)The host's lymphocytes enter the tissues and become suppressed.
B)The host's lymphocytes enter the tissues and become activated.
C)The host's lymphocytes that react to the tissue graft are deleted in the thymus.
D)The donor's lymphocytes suppress the host's lymphocytes, allowing for graft survival.
E)The donor's lymphocytes destroy the host's immune system.

Question 39

Which of the following is TRUE?

A)Vaccines cause autism.
B)Vaccines cause obesity.
C)Vaccines cause cancer.
D)Vaccines cause diabetes.
E)None of the answers are correct.

Question 40

Conditions in which the immune system attacks self-antigens are known as

A)autoimmunity.
B)immune deficiency.
C)hypersensitivities.
D)neuroplasias.
E)None of the answers are correct.