BSC 1407 Ch. 43: The Immune System

Activity: HIV Reproductive Cycle Part B Which of these binds to receptor molecules on the host cell membrane?

A

Which of the following is a specific mechanism by which antibodies function in immunity?

All of the listed responses are correct: - Recruitment of natural killer cells to destroy virus-infected body cells - Neutralization of viruses - Opsonization of bacteria - Activation of complement system

Activity: The Inflammatory Response Part A Which secretion is not a barrier that prevents pathogens from entering the body?

Antigens

Activity: The Adaptive Immune Response Part C Which of the following statements about the clonal-selection theory of immune system function is false?

Antigens are recognized by receptor proteins inside the lymphocyte.

Activity: Immune Responses Part E Clonal selection is the division of _____ that have been stimulated by binding to an antigen, which results in the production of cloned _____.

B cells ... plasma cells and memory cells

Activity: HIV Reproductive Cycle Part E Which of these is reverse transcriptase?

C

Activity: The Adaptive Immune Response Part G How are cytotoxic T lymphocytes (CTLs) produced?

CD8+ T cells divide and differentiate into cytotoxic T lymphocytes.

Current Events: Dangerous Infection Tied To Hospitals Now Becoming Common Outside Them (NPR, 11/25/2018) Part B A C. diff outbreak occurs in a nursing home. Which of the following would likely be best to stop the outbreak?

Disinfect all areas for spores.

Who is credited with performing the first documented immunization?

Edward Jenner

Visualizing the Concept: Clonal selection mobilizes defensive forces against specific antigens Part B A man who has been exposed to the flu virus is tested by his physician. The physician notes that the virus is present but no measurable level of antibodies corresponding to the virus are detected in his body. What might this mean?

He was probably exposed a few days ago and clonal selection has yet to produce plasma cells.

Activity: Immune Responses Part B _____ interact with the antigen-class II MHC complex presented by macrophages.

Helper T cells

Activity: The Adaptive Immune Response Part E How do cells involved in the humoral response respond to antigen presentation on the surface of a B cell?

Helper T cells recognize the receptor-antigen complex and cause plasma and memory cells to be produced to then produce antibodies.

Which of the following classes of immunoglobins crosses the placenta and confers passive immunity to the fetus?

IgG

Activity: The Inflammatory Response Part C How do cells involved in the innate immune response detect the presence of pathogens?

Leukocytes recognize unique molecules on pathogens.

Concept 43.1: In innate immunity, recognition and response rely on traits common to groups of pathogens In what ways does innate immunity protect the mammalian digestive tract?

Lysozyme in saliva destroys bacterial cell walls; the viscosity of mucus helps trap bacteria; acidic pH in the stomach kills many bacteria; and the tight packing of cells lining the gut provides a physical barrier to infection.

Activity: The Adaptive Immune Response Part F Which protein presents viral antigens on the outer surface of cells?

MHC protein

When searching for a donor for an organ transplant, doctors try to match the __________ of the donor and recipient as closely as possible.

MHC proteins

Activity: The Inflammatory Response Part D Which of the following cells can engulf a pathogen?

Macrophages

Which of the following cells are part of the innate, second line of defense?

Macrophages

Besides helper T cells, what are two other types of cells that HIV infects?

Macrophages and brain cells

Which of the following cells does NOT play a role in immunity through the phagocytosis of pathogens?

Natural killer cells

Which of the following functions of plasma-cell secreted antibodies promotes phagocytosis of foreign bacteria?

Opsonization

Activity: The Inflammatory Response Part F Which of the following events occurs first when a wound that breaks the skin has occurred?

Platelets release proteins that form clots and decrease bleeding.

What role do major histocompatibility complex (MHC) molecules play in immunity?

Presenting antigens to T cells

Antibodies belong to which class of proteins?

Receptor

Current Events: When Will a Coronavirus Vaccine be Ready? (The Guardian, 4/6/2020) Part A Which of the following is the biggest hurdle to overcome in creating a vaccine for COVID-19?

Scientists are unsure what vaccine process to follow.

Concept 43.2: In adaptive immunity, receptors provide pathogen-specific recognition Why is the adaptive immune response to an initial infection slower than the innate response?

Sufficient numbers of cells to mediate an innate immune response are always present, whereas an adaptive response requires selection and proliferation of an initially very small cell population specific for the infecting pathogen.

Scientific Skills Exercise: Comparing Two Variables on a Common x-Axis Part I - Making a prediction Scientists can now distinguish trypanosomes recognized by antibody A from trypanosomes recognized by antibody B, and they can measure the abundance of each type of trypanosome. If you plotted the abundance of each type or trypanosome versus time for the same patient, what would you expect to see?

The abundance of trypanosomes recognized by antibody A should peak at day 8; the abundance of trypanosomes recognized by antibody B should peak at day 14.

Everyday Biology: Germs on a Plane Part B In the mock-up of an airplane cabin, there were heated yellow bags where people would normally sit. Why?

The bags are added to create an experimental model that would be most similar to an actual plane full of people.

Visualizing the Concept: Clonal selection mobilizes defensive forces against specific antigens Part C Which is a true statement about memory cells?

They have a longer lifespan than plasma cells.

Scientific Skills Exercise: Comparing Two Variables on a Common x-Axis Part H Do the new data support the hypothesis that the parasite switched surface glycoproteins once the host immune system responded to the original glycoprotein?

Yes. The data suggest that the parasite first displayed glycoprotein A, then glycoprotein B, and then a third glycoprotein.

Histamine is an important signaling molecule in the immune system that directly triggers __________.

blood vessels to dilate and become more permeable

Lysozyme plays a role in immunity through _________.

breaking down bacterial cell walls

Activity: HIV Reproductive Cycle Part C What is the function of reverse transcriptase?

catalyzing the formation of DNA from a RNA template

B lymphocytes __________.

multiply and make antibodies that circulate in blood and lymph

Activity: Immune Responses Part C B cells that have been stimulated by interleukin-2 develop into _____.

plasma cells

Activity: HIV Reproductive Cycle Part G What enzyme is responsible for the process seen here?

reverse transcriptase

Activity: HIV Reproductive Cycle Part A The genetic material of HIV consists of _____.

single-stranded RNA

Vaccination led to the eradication of the disease ________.

smallpox

In insects, which of the following is analogous to mammalian epithelial tissue, in that it serves as a first line of defense against infection?

A chitinous exoskeleton

Which of the following is NOT a disease caused by actions of the immune system?

All of the listed responses are correct: - Ulcerative colitis - Crohn's disease - Lupus - Rheumatoid arthritis

Current Events: Dangerous Infection Tied To Hospitals Now Becoming Common Outside Them (NPR, 11/25/2018) Part D Based on this research, which of the following studies would likely be best to create better treatments for future C. diff outbreaks?

An in-depth study of the gut microbiome in humans.

Which of the following cell types carries out humoral immunity?

B cells

Someone infected by chicken pox as a child is unlikely to suffer from this disease a second time. This is due to immunological memory, a reservoir of what type of cells that were generated following the initial exposure?

Both T cells and B cells

Scientific Skills Exercise: Comparing Two Variables on a Common x-Axis Part E Assume that a drop in parasite abundance reflects an effective immune response by the host. What could explain the pattern revealed by your graph?

By the time the host developed an effective immune response to one surface glycoprotein, the parasite had changed to a different glycoprotein.

Everyday Biology: Germs on a Plane Part E Why are children more likely to pick up germs in public places?

Children tend to be more tactile, and may not wash their hands as often as they should.

Everyday Biology: Germs on a Plane Part G Which of the following would be the best experimental design for a study looking at the effect of hand-washing on the incidence of acquiring an infectious disease?

Choose a setting where a large number of people consistently spend time, such as an office building. Randomly assign everyone to one of two groups. Ask one group to wash their hands every hour, and ask the other group to avoid washing their hands except when truly necessary. Compare the incidence of infectious disease between the two groups over a period of months or years.

Activity: The Adaptive Immune Response Part D What is the final step in the cell-mediated response to a viral infection?

Cytotoxic T lymphocytes punch holes in the membranes of infected host cells

Activity: HIV Reproductive Cycle Part F Which of these is the viral genome?

E

Scientific Skills Exercise: Comparing Two Variables on a Common x-Axis Part G - Interpreting the graph See a graph that combines the antibody data you just graphed with the parasite number data (Figure 2). What pattern do you observe by comparing the three data sets over the same period?

Each of the first two major decreases in parasite number (from day 8 to day 10 and from day 14 to day 18) was associated with an increase in the level of a different type of antibody.

Activity: The Inflammatory Response Part B True or false? The leukocytes of the innate immune system are B cells, macrophages, and neutrophils.

False

Visualizing the Concept: Clonal selection mobilizes defensive forces against specific antigens Part A The words "antigen" and "virus" are interchangeable.

False

Everyday Biology: Germs on a Plane Part F Which of the following would be the best experimental design for a study looking at the risk of getting an infectious disease from using public transportation?

Follow a very large set of people in order to reduce the effect of socioeconomic status. One group is comprised of people who frequently use public transportation, and the other group never uses public transportation. Compare the incidence of infectious disease between the two groups. Collect data without telling the participants too much about the study, so that they do not alter their normal behaviors.

Current Events: Dangerous Infection Tied To Hospitals Now Becoming Common Outside Them (NPR, 11/25/2018) Part A While working as a microbiologist, you discover a new species of Clostridium. Which of the following is true?

It is most likely harmless.

Which of the following is NOT a characteristic of innate immunity?

It is present only in vertebrates.

Concept 43.4: Disruptions in immune system function can elicit or exacerbate disease Is being infected with HIV the same as having AIDS? Explain.

No. AIDS refers to a loss of immune function that can occur over time in an individual infected with HIV. However, certain multidrug combinations ("cocktails") or rare genetic variations usually prevent progression to AIDS in HIV-infected individuals.

Concept 43.3: Adaptive immunity defends against infection of body fluids and body cells Is immunological memory after a natural infection fundamentally different from immunological memory after vaccination? Explain.

No. Immunological memory after a natural infection and that after vaccination are very similar. There may be minor differences in the particular antigens that can be recognized in a subsequent infection.

Scientific Skills Exercise: Comparing Two Variables on a Common x-Axis Part F - Comparing two variables on the same graph Many decades after scientists first observed the pattern of Trypanosoma abundance over the course of infection, researchers identified antibodies specific to different forms of the parasite's surface glycoproteins. This table lists the relative abundance of two such antibodies during the early period of chronic infection, using an index ranging from 0 to 1. Note that these data were collected over the same period of infection (days 4-24) as the parasite abundance data you graphed earlier. Therefore, you can incorporate these new data into your first graph. However, since the antibody abundance data are measured in a different way than the parasite abundance data, you will use a second y-axis on the right side of your graph. Having two y-axes enables you to compare how two dependent variables change relative to a shared independent variable.

Now you will graph the antibody data using the y-axis on the right. Click "Add Element" and select the label "Antibody for glycoprotein A over time." Plot the data in that column of the table. Click "Add Element" and select the label "Antibody for glycoprotein B over time." Plot the data from that column of the table. See Hint 1 if you need help using the graphing tool.

Current Events: Dangerous Infection Tied To Hospitals Now Becoming Common Outside Them (NPR, 11/25/2018) Part E You are prescribed antibiotics for strep throat. Which of the following is true?

The drug will kill many kinds of bacteria.

Why is the development and distribution of a new flu vaccine required every year?

The influenza virus undergoes frequent mutations and evolves rapidly.

In a series of immune system experiments, the thymus glands were removed from baby mice. Which of the following would you predict as a likely result?

The mice readily accepted tissue transplants.

Scientific Skills Exercise: Comparing Two Variables on a Common x-Axis Part D - Interpreting the graph See a graph of the data, similar to the one you just made (Figure 1). Which of the following describes the pattern revealed by the graph?

The number of parasites goes through cycles of increase followed by decrease.

Which statement describes what would most likely happen to microbes in the blood?

They are phagocytosed by macrophages in the spleen.

Activity: The Inflammatory Response Part E Which of the following statements best describes the role of mast cells in the inflammatory response?

They release chemicals that dilate blood vessels near the wound site, allowing blood components to enter the region from the bloodstream.

Activity: The Adaptive Immune Response Part A Which structure is not a component of the adaptive immune system?

Tissues

Scientific Skills Exercise: Comparing Two Variables on a Common x-Axis Part C

To create the graph, first click "Add Element" and select the label "Number of parasites (in millions) per mL of blood over time." (See Hint 1 if you need help using the graphing tool.)

Activity: The Adaptive Immune Response Part B True or false? B cells were originally isolated from the bursa in chickens, and their function is to produce antibodies; T cells were originally isolated from the thymus in mice, and their functions include killing host cells that are being infected with a virus.

True

Activity: The Inflammatory Response Part G The site of inflammation may become swollen due to the increased numbers of cells and fluids at the site and painful due to signals from pain receptors.

True

Which of the following organisms would produce antibodies as part of an immune response?

Whale

Current Events: Dangerous Infection Tied To Hospitals Now Becoming Common Outside Them (NPR, 11/25/2018) Part C You are a doctor. A patient presents with diarrhea and tests positive for C. diff. Which of the following is true?

Your patient may or may not have recently taken antibiotics.

Acquired Immunity Part C - Activation of B cells B cells are involved in the humoral immune response. The flowchart below summarizes the steps involved in B cell activation. Drag the labels to their appropriate locations on the flowchart below. (Note that TCR stands for T cell receptor.)

a. antigen-presenting cell presents antigen on class II MHC b. helper T cell recognizes antigen using TCR and CD4 c. helper T cell binds to B cell and releases cytokines d. B cell cell presents antigen on class II MCH molecule e. B cell differentiates into plasma cells and memory cells f. plasma cells secrete antibodies

Acquired Immunity Part B - Action of cytotoxic T cells Cytotoxic T cells are the effector cells in the cell-mediated immune response. The diagram below summarizes the interaction of a cytotoxic T cell and its target cell. Drag the labels to their appropriate locations on the diagram below using the following steps. Use targets of Group 2 to indicate the types of cells shown. Then, use targets of Group 1 to the remaining targets. The labels under the cell on the left should describe what happens to that cell at each step. The labels under the cell on the right should describe what happens to that cell at each step. Note that TCR stands for T cell receptor.

a. cytotoxic T cell b. infected cell c. recognizes cell using TCR & CD8 d. presents antigen on class I MHC e. releases perforin and granzymes f. undergoes enzyme attack g. moves on to destroy another cell h. undergoes apoptosis

Everyday Biology: Germs on a Plane Part C Which setting has the shortest time span for air refreshment - in other words, which setting has the most frequent air exchange with fresh air?

airplane cabin

Interpreting Data: Primary and Secondary Immune Responses Part G Is this statement supported or not supported by the graph? A third exposure to antigen X will produce an even stronger immune response than the second exposure did.

cannot be determined from the graph

The proliferation of the B lymphocyte to which a specific antigen binds is referred to as __________.

clonal selection

Scientific Skills Exercise: Comparing Two Variables on a Common x-Axis Part A - Making a graph with the data The first study measured the abundance of parasites in the blood of one human patient during the first few weeks of a chronic infection. The results are shown in the table. You decide to plot the data as a line graph. Which column represents the independent variable, and which axis should it be plotted on?

day; x-axis

Our immune system does not usually attack our own healthy tissues because lymphocytes that target "self" tissue are __________.

destroyed or rendered nonfunctional

Everyday Biology: Germs on a Plane Part D In an airplane, from whom are you most likely to acquire a cold or flu virus?

from a sick person sitting next to you

Activity: HIV Reproductive Cycle Part D What is the source of a viral envelope?

host cell membrane

Acquired Immunity Part A - Overview of acquired immunity Acquired immunity involves both a humoral immune response and a cell-mediated immune response. To review the definitions of these immune responses, see Hint 1. Sort the items into the appropriate bins depending on whether they are involved in the humoral response, the cell-mediated response, or both the humoral and the cell-mediated responses. (If you are not sure what some of the items are, see Hint 2.)

humoral response: - B cells - plasma cells - antibodies cell-mediated response: - cytotoxic T cells both: - memory cells - antigen-presenting cells - helper T cells and cytokines

Herpes simplex viruses, such as those that cause cold sores, can evade the immune system and persist in the body by __________.

infecting cells and then entering a largely inactive state

Anaphylactic shock is a life-threatening condition in which __________.

inflammatory chemicals released from mast cells lead to an inability to breathe and a lack of blood flow

Passive immunity differs from active immunity in that passive immunity ___________.

is conferred by antibodies produced by another individual

Activity: Immune Responses Part A Which of these cells is a phagocytic leukocyte that can engulf a foreign bacterium?

macrophage

Activity: Immune Responses Part F Which of these cells is responsible for the rapidity of the secondary immune response?

memory cells

Interpreting Data: Primary and Secondary Immune Responses Part E Is this statement supported or not supported by the graph? The primary immune response takes about 28 days to reach its peak.

not supported

Interpreting Data: Primary and Secondary Immune Responses Part H Is this statement supported or not supported by the graph? The primary immune response to antigen X occurred just as fast as the secondary immune response to antigen X.

not supported

Scientific Skills Exercise: Comparing Two Variables on a Common x-Axis Part B Which column represents the dependent variable, and which axis should it be plotted on?:

number of parasites (in millions) per mL of blood; y-axis

Activity: Immune Responses Part D The role of cytotoxic T cells is the secretion of _____, which plays a role in the _____ immune response.

perforin ... cell-mediated

Activity: Immune Responses Part G Which of these cells produce and secrete antibodies?

plasma cells

Activity: HIV Reproductive Cycle Part H Double-stranded viral DNA is incorporated into a host cell as a _____.

provirus

Interpreting Data: Primary and Secondary Immune Responses Part F Is this statement supported or not supported by the graph? The secondary immune response is stronger than the primary immune response.

supported

Interpreting Data: Primary and Secondary Immune Responses Part A What does the y-axis of this graph represent?

the antibody concentration in the blood

Interpreting Data: Primary and Secondary Immune Responses Part B What does the blue line on this graph represent?

the concentration of antibodies to antigen X

Interpreting Data: Primary and Secondary Immune Responses Part C What does the first blue peak (around day 17) represent?

the highest concentration of antibodies that occurs after the first exposure to antigen X

Interpreting Data: Primary and Secondary Immune Responses Part D What does the second blue peak (around day 40) represent?

the peak of the secondary immune response to antigen X

The idea behind vaccination is to induce __________ without requiring the vaccinated individual to get sick.

the primary immune response

In humans, the first line of defense against infection is __________.

the skin and mucous membranes

Everyday Biology: Germs on a Plane Part A What is the major method of transmission of infectious disease when using public transportation?

touching surfaces that sick people have touched