Chapter 43: Animal Immune System (Mastering Biology & Dynamic Study Module)

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 recognized antigen using TCR and CD4 - C. Helper T cell binds to B cell and releases cytokines - D. B cell presents antigen on class II MHC molecule - E. B cell differentiates not plasma cells and memory 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.

- A. Cytotoxic T cell - B. Infected cell - C. Recognizes cell using TCR and CD8 - D. Presents antigen on class 1 MHC - E. Releases perforin and granzymes - F. (Undergoes enzyme attack - G. Moves on to destroy another cell - H. Undergoes apoptosis

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

- Lupus - Crohn's Disease - Ulcerative Colitis - Rheumatoid Arthritis (ALL OF THE LISTED RESPONSES ARE CORRECT)

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

- Neutralization of viruses - Opsonization of bacteria - Recruitment of natural killer cells to destroy virus-infected body cells - Activation of complement system (ALL OF THE LISTED RESPONSES ARE CORRECT)

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 secretion is not a barrier that prevents pathogens from entering the body?

Antigens

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

Which of the following cell types carries out humoral immunity?

B cells

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 and memory cells

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

Blood vessels to dilate and become more permeable

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

Lysozyme plays a role in immunity through _________.

Breaking down bacterial cell walls

Each person makes more than 1 million different B cell antigen receptors and more than 10 million different T cell antigen receptors. How is such diversity in antigen receptors generated?

By combining variable elements, the immune system assembles many different receptors from a much smaller collection of parts

How are cytotoxic T lymphocytes (CTLs) produced?

CD8+ T cells divide and differentiate into cytotoxic T lymphocytes

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

Clonal selection

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

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

Destroyed or rendered nonfunctional

Who is credited with performing the first documented immunization?

Edward Jenner

The words "antigen" and "virus" are interchangeable.

False

True or false? The leukocytes of the innate immune system are B cells, macrophages, and neutrophils.

False

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.

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

_____ interact with the antigen-class II MHC complex presented by macrophages.

Helper T cells

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

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.

Humoral response: - B cells - Antibodies - Plasma cells Cell-Mediated Response: - Cytotoxic T cells Both: - Helper T cells and cytokines - Memory cells - Antigen-presenting cells

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

IgG

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

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

It is present only in vertebrates.

How do cells involved in the innate immune response detect the presence of pathogens?

Leukocytes recognize unique molecules on pathogens

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

Which protein presents viral antigens on the outer surface of cells?

MHC protein

Which of these cells is a phagocytic leukocyte that can engulf a foreign bacterium?

Macrophage

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

Macrophages

Which of the following cells can engulf a pathogen?

Macrophages

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

Macrophages and brain cells

Which of these cells is responsible for the rapidity of the secondary immune response?

Memory cells

B lymphocytes __________.

Multiply and make antibodies that circulate in blood and lymph

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

The role of cytotoxic T cells is the secretion of _____, which plays a role in the _____ immune response.

Perforin...Cell-mediated

B cells that have been stimulated by interleukin-2 develop into _____.

Plasma cells

Which of these cells produce and secrete antibodies?

Plasma cells

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

Vaccination led to the eradication of the disease ________.

Smallpox

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.

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

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

They are phagocytosed by macrophages in the spleen.

Which is a true statement about memory cells?

They have a longer lifespan than plasma cells

Which of the following statements best describes the role of mast cells in the inflammatory response?

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

Which structure is not a component of the adaptive immune system?

Tissues

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

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

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

Whale