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46 terms

Ch.24 Exam #3 Bio 121

Study questions for Exam #3
The body's innate defenses against infection include
barriers such as dead skin cells and mucus
Which of the following wander through the interstitial fluid and consume any bacteria and virus-infected cells they encounter?
Natural killer cells
attack virus-infected cells by releasing chemicals that lead to cell death.
What substance, produced by virus-infected cells, diffuses to neighboring cells to help them fight a viral infection?
A researcher who detects a higher-than-normal amount of interferon in a laboratory rat would correctly conclude that
the rat has, or recently had, a viral infection.
Some complement proteins
help trigger the inflammatory response.
Which of the following helps activate our nonspecific (innate) defense system?
When you cut yourself, the damaged cells immediately release chemical alarm signals, such as
Which of the following is an immediate effect of histamine release?
dilation of local blood vessels
The major result of the inflammatory response is to
remove contaminating microorganisms and initiate repair of damaged tissues.
Bacterial infections can cause a serious, potentially fatal systemic inflammatory response called
septic shock.
The human lymphatic system consists of all of the following structures except the
The two main functions of the lymphatic system are
returning tissue fluid to the circulatory system and fighting infections.
A molecule that can elicit an adaptive immune response is called
an antigen.
One kind of vaccine consists of
a harmless variant strain of a disease-causing microbe.
The transfer of antibodies in breast milk to an infant is an example of ________ immunity.
Passive immunity depends upon
antibodies made by another organism.
Some viral diseases are dangerous only when a person is infected for the first time; subsequent infections produce only mild symptoms or go entirely unnoticed. This pattern can be explained by the action of _____.
memory cells that trigger a secondary immune response
A virus enters your system and successfully invades and infects a cell. At this point it is vulnerable to recognition or attack by _____.
T cells
When a B cell binds to a virus or other pathogen, it _____.
becomes activated, divides rapidly, and thereby mounts a specialized response against the pathogen.
Antibodies are _____.
specialized proteins that attach to pathogens and disable them or mark them for destruction by immune cells
In the immune response, the end goal is to disable or kill pathogens that invade the body. But first, antibody proteins or proteins in immune cell membranes must recognize and bind to invaders. This is a challenge, given the vast diversity of pathogens that can infect us. To meet this challenge, immune proteins _____.
are diverse: each immune protein can bind to only one or a few pathogens, but immune proteins are tremendously diverse, so the system is likely to possess a "match" to nearly any pathogen
Which of the following cell types is responsible for the humoral immune response?
B cells
Which of the following statements about the humoral immune response is true?
The humoral immune response defends primarily against bacteria and viruses present in body fluids.
Which of the following cell types is responsible for the cell-mediated immune response?
T cells
The adaptive immune system is capable of mounting specific responses to particular microorganisms because
the body contains an enormous diversity of lymphocytes, each with the ability to respond to a different antigen.
Which of the following statements regarding antigens and antibodies is false?
Each antibody has only one antigen-binding site.
A primary immune response is
the immune response elicited by the first exposure of lymphocytes to a particular antigen.
Clonal selection
describes the proliferation of B and T lymphocytes after they have been activated by an antigen.
When a B cell first interacts with its particular antigen, the B cell
differentiates and develops into a clone of antibody-producing effector cells.
Which of the following choices best describes a plasma cell?
It is a differentiated B cell.
The secondary immune response occurs when memory cells bind to
Which of the following distinguishes the secondary immune response from the primary immune response?
The secondary response is faster and stronger.
Antibody molecules may function by causing the
agglutination of viruses or bacteria.
The complement system can be activated by
antigen-antibody complexes.
The basic function of activated T cells is to battle
pathogens that have already entered body cells.
What type of cell helps to stimulate B cells to produce antibodies?
helper T cell
________ can destroy infected cells.
Cytotoxic T cells
Which of the following types of cells does HIV preferentially infect?
helper T cells
HIV is a virus that is particularly difficult to eradicate
because it mutates to produce new drug-resistant strains.
Why has it been so difficult for researchers to develop effective antivirals for HIV?
because HIV has a high mutation rate
________ genes are responsible for coding for self-proteins.
Which of the following diseases is thought to be an autoimmune disease?
insulin-dependent diabetes mellitus
What type of immune response is always disadvantageous to a person?
Which of the following compounds is produced and secreted by mast cells during an allergic reaction?
Anaphylactic shock is an example of an
allergic response.