Flash-card set – Practice Test #1 (BIOL 2013 Exam 4)

Which of the following is NOT part of the first line of defense in non-specific host resistance?

Inflammation

Cigarette smoke paralyzes cilia in the respiratory tract. This interferes with which line of defense?

First line of defense

Which statement about fever is true?

Fever is beneficial to the host up to a point.

In the fever process, which chemical signals the hypothalamus to produce prostaglandins?

Interleukin I

Why might taking ten showers a day weaken your defenses?

Washing oils off the skin removes part of the first line of defense.

During inflammation after a knife cut, which cells leave the blood vessels to attack bacteria?

Neutrophils

Antigens are best described as…

Always foreign to the host and reasonably large.

What is true of a hapten?

It cannot by itself trigger antibody production.

A typical antibody can bind two epitopes, is a protein, and can itself act as an antigen.

All of the above (true).

In some people, penicillin can bind a normal protein so the combination induces antibody synthesis.

True

Which immunoglobulin is most commonly found on the surface of B cells?

IgD

Which immunoglobulin fixes complement but does not cross the placenta?

IgM

The two most important phagocytic cells are…

Neutrophils and macrophages

In a phagocyte, which structure stores digestive enzymes?

Lysosome

In humans, stem cells differentiate into B cells in the…

Red bone marrow of the adult

On an activated B cell, the antigen fragment is displayed together with…

Major histocompatibility complex class II (MHC II)

Which cell releases cytokines that activate a B cell to become a plasma cell?

Helper T cell

In an anamnestic (secondary) response, how does IgG production compare with the primary response?

More IgG is produced than in the primary response.

Opsonization primarily does what?

Enhances phagocytosis

Antivenom treatment after a spider bite provides what kind of immunity?

Artificial passive immunity

Natural passive immunity is provided chiefly by which immunoglobulins?

IgA and IgG

Complement activation requires the antigen to be bound by which antibodies?

IgG or IgM

Antigen–antibody binding can lead to opsonization, neutralization, and complement activation.

True

Monoclonal antibody technology produces…

Pure antibodies directed against one epitope.

A person genetically predisposed to ragweed allergy shows what on first exposure?

No outward indication of allergy.

Allergy-shot desensitization works mainly by inducing synthesis of…

Blocking IgG antibodies

Which item does not cause a true allergic response?

Lactose

Anaphylaxis results from degranulation of mast cells.

True

Hemolytic Disease of the Newborn is which hypersensitivity type?

Type II – Cytotoxic reactions

Large antigen–antibody complexes deposited in vessel walls may trigger what hypersensitivity?

Immune complex–mediated hypersensitivity (Type III)

Transfusing an A⁺ person with A⁻ blood causes which immediate effect?

None of the above (no adverse reaction).

Toxoids are best defined as…

Inactivated toxins

A first vaccination induces what kind of immune response?

Primary humoral immune response

Antisera are most often used for what purpose?

Preventing disease after exposure

Vaccines can be composed of toxoids.

True

One reason not to immunize against everything is the risk of developing…

Immune complex syndrome

Which is correct regarding transfer of immunity?

Cellular immunity can be transferred by injection of white blood cells.

An immune response directed against tumor cells is mediated chiefly by…

Cytotoxic T cells

HIV is transmitted primarily by…

Sexual activity and exchange of blood

The major cellular targets of HIV are…

Helper T cells and macrophages