1
.
What is the mechanism that skin uses to protect against diseases caused by organisms?
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high pH
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mucus
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tears
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desiccation
2
.
This image shows the growth rate of some types of bacteria in different pH values.
Based on this image, and keeping in mind the skin forms a barrier against many types of bacteria, make a claim about the likely values for skin's pH.
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A neutral pH of 7.0.
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Around 6.5.
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Between 5.5 and 7.5.
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More than 7.5 or less than 5.5.
3
.
Which of the following produces an immediate innate immune response by recognizing an invading pathogen and engulfing it?
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macrophage
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cytokine
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inflammation
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antibody
4
.
How does inflammation develop?
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Inflammation is induced by molecules such as cytokines and histamine that are produced by various host cells in response to pathogens at the site of injury or infection.
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During inflammation, all blood cells retreat from the site of infection in order to protect the circulatory system from pathogen infection.
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Inflammation is an ongoing condition in the human body, part of the way that the innate immune system can respond immediately to an infection.
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When an infection occurs, an immediate inflammatory response occurs as soon as pathogens enter the body.
5
.
Which innate immune system component uses major histocompatibility class (MHC) I molecules directly in its defense strategy?
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macrophages
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neutrophils
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natural killer cells
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interferon
6
.
What is the difference between natural killer cells and macrophages?
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Natural killer cells are not always present in the body and must be induced, whereas macrophages are constantly present.
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Natural killer cells actually kill foreign cells, whereas macrophages serve only a signaling function.
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Only macrophages can invade host tissues to fight foreign cells that make their way into those tissues.
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Natural killer cells kill foreign cells through the processes of lysis and proteolysis, whereas macrophages kill foreign cells by phagocytosis.
7
.
What is the composition of major histocompatibility class (MHC) I molecules?
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lipids
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nucleic acids
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carbohydrates
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proteins
8
.
What is the function of major histocompatibility class (MHC) I molecules?
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MHC I molecules assist with strengthening the cell membrane.
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MHC I molecules present antigens on the surface of a cell.
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MHC I molecules allow movement of materials across the cell membrane.
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MHC I molecules provide signals for processes involved in cell division.
9
.
What is the complement system?
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The complement system contains macrophages that phagocytize foreign pathogens.
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The complement system monitors MHC I molecules on cells and destroys any cell that displays an antigen belonging to a pathogen.
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The complement system contains a group of about 20 proteins in the blood that attack pathogens in a cascading fashion to mark and destroy them.
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The complement system is made up of antibodies specific to each pathogen that are synthesized when a pathogen enters the body.
10
.
Which of the following occurs more rapidly as the result of activation of the complement system?
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pathogen invasion
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pathogen detection
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pathogen reproduction
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pathogen engulfment
11
.
What is another term for adaptive immunity?
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acquired immunity
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innate immunity
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passive immunity
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humoral immunity
12
.
How does adaptive immunity work?
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A person is born having a specific immune responses against any pathogen that the body is exposed to.
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A person is born with the ability to develop a specific immune response against any pathogen within minutes of being exposed to that pathogen.
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A person does not have any immune response against a pathogen, but develops a temporary specific response to that pathogen that is then forgotten.
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A person does not have specific immune response against a pathogen, but develops a specific response to that pathogen that is rapidly recalled later if infection by the same pathogen occurs again.
13
.
What component of the innate immune system is not part of the adaptive immune system?
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T cells
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antibodies
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mast cells
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B cells
14
.
What is the difference between innate and adaptive immune responses?
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The adaptive immune system is faster-acting than the innate immune system.
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The adaptive immune system produces a longer-lasting defense than the innate immune system.
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The innate immune system produces a more specific defense than the adaptive immune system.
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The innate immune system has a more sophisticated memory than the adaptive immune system.
15
.
Which cells are unique to the humoral immune response?
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cytotoxic T cells
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antigen-presenting cells
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helper T cells
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B cells
16
.
This image shows how the humoral immune system works.
What is happening at step 2?
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A B cell is preparing to release antibodies.
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A B cell is engulfing the antigens.
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A B cell is displaying the antigens of the pathogen.
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A B cell is getting ready to divide.
17
.
An antibody sometimes binds to an antigen other than the antigen that elicited its synthesis. What term refers to this behavior?
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avidity
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cross reactivity
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hypersensitivity
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affinity
18
.
A biologist runs some tests and observes that the same antibody binds to several different proteins. Why might this occur?
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The antibody is showing that it has high affinity for antigens.
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The antibody is showing that it has high avidity for antigens.
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The antibody is showing cross reactivity to the antigens.
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The antibody is showing hypersensitivity to the antigens.
19
.
How many and what types of polypeptides make up an antibody molecule?
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one heavy polypeptide chain and one light polypeptide chain
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two heavy polypeptide chains and one light polypeptide chain
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two heavy polypeptide chains and two light polypeptide chains
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one heavy polypeptide chain and two light polypeptide chains
20
.
Why do antibodies isolated from the same individual show a variety of constant domains?
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The antibodies were synthesized in response to infections by different pathogens.
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The antibodies were transmitted as the result of passive immunity.
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The antibodies have different specificities of antigen binding.
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The antibodies belong to different classes of immunoglobulin molecules.
21
.
What enzyme is responsible for the random excision of variable gene segments making up an antibody light chain in DNA?
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DNA polymerase
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DNA recombinase
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DNA ligase
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DNA helicase
22
.
How are antibodies produced in a B cell?
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RNA processing → DNA rearrangement → transcription → translation → mature antibody
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Transcription → RNA processing → DNA rearrangement → translation → mature antibody
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DNA rearrangement → RNA processing → transcription → translation → mature antibody
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DNA rearrangement → transcription → RNA processing → translation → mature antibody
23
.
This graph shows how well the lungs function result in an allergic patient following exposure to an allergen.
What is the dependent variable in this graph?
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Lung function.
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Time.
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The concentration of the allergen.
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The exposure time to the allergen.
24
.
An allergy has been described as a non-protective immune response. Which statement provides information supporting this description?
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An allergic response occurs when B cells produce IgE molecules in response to a foreign protein, which causes histamine to be released.
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An allergy results from an immune response to a protein that does not cause harm and that the body needs no defense against.
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People with allergies develop unpleasant symptoms such as watery, itchy eyes, swollen tissues, and sneezing.
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When their blood is tested, people with allergies show that they have antibodies that bind to one or more foreign proteins.
25
.
What is the term for antibodies that inappropriately mark self components as foreign?
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cross reactive
-
epitopes
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allergens
-
autoantibodies
26
.
Why do some people with type 1 diabetes develop the disease as the result of an immune response?
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Their B cells produced IgE molecules in response to a harmless protein, which caused histamine to be released.
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Their B cells responded to a self protein to produce autoantibodies, which elicited inflammation that caused organ damage.
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They had a delayed response to a harmful protein that entered the body and activated both the innate and adaptive immune systems.
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They acquired antibodies to insulin through passive immunity, and these antibodies bind to insulin whenever it is produced in the body.
27
.
What are the three types of hypersensitivity?
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innate, acquired, and immunodeficiency
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variable, constant, and recombinant
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immediate, delayed, and autoimmunity
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active, passive, and adaptive
28
.
What is the definition of autoimmunity?
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binding of an antibody to a viral antigen
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immune response to self antigens
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maladaptive immune response to harmless foreign proteins
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failure to mount an immune response