Defense

Which of the following is an example of a subunit vaccine?

An isolated surface protein of a target virus is used to make the vaccine.

What defenses can bacteria deploy against viruses and other bacteria?

Exude toxic chemicals and block injection

Phagocytic cells of innate immunity of vertebrates include ________. I. neutrophils II. macrophages III. platelets IV. mast cells

I and II

Arrange in the correct sequence these 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.

III → IV → II → I → V

Put these steps of the HR response in the correct order: I. Cells in the infected area rapidly die by suicide II. Cell walls are reinforced to prevent pathogen movement III. Stomata close keeping out pathogens IV. Toxins targeting the pathogen are produced.

III, IV, II, I

Why might humans need yearly vaccination for influenza?

Influenza virus undergoes rapid mutation that alters the surface proteins in the cells it infects.

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

It enables a rapid defense against an antigen that has been previously encountered.

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

One has a major role in antibody production, while the other has a major role in cytotoxicity.

What organisms engage in compartmentalization to defend against pathogens?

Protists

Use the following information to answer the question below. Some plants continually produce secondary defense compounds. Other plants are induced to form secondary defense compounds when they are injured. Corn seedling leaves that are chewed on by the caterpillars of a type of cutworm moth emit immediate volatile chemicals (LOX products), and after 6 hours large amounts of terpenoid compounds are released into the air. The terpenoids are released not only from the leaf being chewed but from all leaves of the plant. The terpenoid compounds attract a parasitoid wasp female that lays her eggs on the caterpillar. When the wasp larvae hatch, they eat and kill the moth caterpillar. (T.C.J. Turlings, J. H. Loughrin, P. J. McCall, U. S. R. Rose, W. J. Lewis, and J. H. Tumlinson. 1995. How caterpillar-damaged plants protect themselves by attracting parasitic wasps. Proceedings of the National Academy of Sciences 92:4169—74.) Refer to the paragraph on how caterpillar-damaged plants protect themselves by attracting parasitic wasps. What can you conclude based only on the information in the preceding paragraph?

The parasitoid wasp is attracted by compounds produced by an injured corn plant.

A fruit fly, internally infected by a potentially pathogenic fungus, is protected by its ________.

Toll proteins

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

You had an adaptive immunity to that virus.

Adaptive immunity is based upon ________.

antigen-specific recognition

The receptors on T cells and B cells bind to ________.

antigens

B-cell receptors bind to antigens that are either freely dissolved or present on the surface of invading or foreign cells. T-cell receptors ________.

bind to antigen fragments presented on major histocompatibility (MHC) complexes by host cells

When an arborist prunes a limb off a valuable tree, he or she may paint the cut surface with a nontoxic sealant. The primary purpose of the paint is to ________.

block entry of pathogens through the wound

Select the pathway that would lead to the activation of cytotoxic T cells.

body cell becomes infected with a virus → new viral proteins appear → class I MHC molecule-antigen complex displayed on cell surface

The cell-mediated immunity that destroys virally infected cells primarily involves ________.

cytotoxic T cells

Which of the following cells are involved in cell-mediated immunity and also respond to class I MHC molecule-antigen complexes?

cytotoxic T cells

T cells of the immune system include ________.

cytotoxic and helper cells

The major histocompatibility (MHC) molecule is important in a T cell's ability to ________.

distinguish self from nonself

What defenses can bacteria utilize against predators, bacteria, and viruses?

exude toxic chemicals, block injection, and form biofilms.

Antigens are ________.

foreign molecules that can initiate an immune response

Antigens are ________.

foreign molecules that trigger an immune response

One way bacteria can defend themselves against predators is to:

form biofilms so predators cannot get to them to consume them.

A cell type that interacts with both the humoral and cell-mediated immune pathways is a ________.

helper T cell

An inflammation-causing signal released by mast cells at the site of an infection is ________.

histamine

Inflammatory responses typically include ________.

increased activity of phagocytes in an inflamed area

A boy falls while riding his bike. A scrape on his hand almost immediately begins to bleed and becomes red, warm, and swollen. What response is occurring?

inflammatory response

The immune response that is rapid but generic is called ________.

innate immune response

What kind of immune responses do insects have?

innate immunity only

Innate immunity ________.

is activated immediately upon infection

For the successful development of a vaccine to be used against a pathogen, it is necessary that ________.

lymphocytes with receptors that can bind to the pathogen

The cells and signaling molecules involved in the initial stages of the inflammatory response are ________.

macrophages and chemokines

A function of antibodies is to ________.

mark pathogenic cells for destruction

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

memory

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?

memory cell

Secondary immune responses upon a second exposure to a pathogen are due to the activation of ________.

memory cells

The transduction pathway that activates systemic acquired resistance in plants is initially signaled by ________.

methyl salicylate

Phagocytosis of microbes by macrophages is enhanced by ________. I. the binding of antibodies to the surface of microbes II. antibody-mediated agglutination of microbes III. the release of cytokines by activated B cells

only I and II

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 identical 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.

only I, II, and IV

Which of the following would help a virus avoid triggering an effective adaptive immune response? I. having frequent mutations in genes for surface proteins II. building the viral shell from host proteins III. producing proteins very similar to those of other viruses IV. infecting and killing helper T cells

only I, II, and IV

Lymphocytes mature in the ________. I. spleen II. thymus III. bone marrow

only II and III

Plants can defend against some herbivores using ________.

physical defenses such as thorns and trichomes.

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

presentation of MHC (major histocompatibility complex)-antigen complex on a cell surface

One way with which bacterial defend against predation is by:

producing biofilms

Which of the following is the most likely plant response to an attack by herbivores?

production of chemical compounds for defense or to attract predators of the herbivores

The primary function of humoral immunity (humoral response) is to ________.

protect the body against extracellular pathogens

Compounds produced by plants to defend against herbivores and pathogens are called ______.

secondary metabolites

Immunological memory accounts for ________.

the ancient observation that someone who had recovered from the plague could safely care for those newly diseased

A key part of the humoral immune response is ________.

the production of antibodies by plasma cells

Which of the following is TRUE of the humoral immune response and NOT true of the cell-mediated immune response? Only the humoral immune response ________.

uses antibodies as its main weapon

For a plant to initiate chemical responses to herbivory before it is directly attacked by herbivores, ________.

volatile "signal" compounds must be perceived

The activation of helper T cells is likely ________.

when an antigen is displayed by a dendritic cell

Vegetative incompatibility is ____________.

when hyphae from separate individuals of fungi are unable to fuse due to genetic differences or detection of an invasive pathogen infecting one of them.