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Antibodies carry out which of the following functions?
Antibodies are part of humoral immunity. The humoral pathway protects against extracellular pathogens. Antibodies are produced and secreted by B lymphocytes (B cells). They recognize free antigens, initiate activation of other immune cells, and coat the antigen for destruction (which may or may not be cellular).
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Which of the following attaches directly to pathogens to mark them for destruction?
Antibodies are produced by plasma cells (mature B-cells) with specific binding affinity for surface proteins that have been presented by antigen-presenting cells, like dendritic cells and macrophages. Once the plasma cell is stimulated by the presence of the specific antigen, it increases production of its antibody. These antibodies enter the blood and bind the antigen molecules on the surface of the pathogen cell. Cytotoxic T-cells and cytokines can then interact with the antibodies to initiate lysis of the infected cell or pathogen.
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Which of the following statements is true?
It helps to think of antigens and antibodies like a lock and key: they are highly specific for one another. B-lymphocytes create only one type of antibody. When this antibody attaches to an antigen presented by a macrophage or antigen-presenting cell, the B-lymphocyte will differentiate with the help of a helper T-cell. The result is replication of the B-lymphocyte to produce more of the same antibody from plasma cells and generate memory B-cells to easily respond in the event of a second infection by the pathogen.
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The human immune system is organized along two broad arms: innate immunity and adaptive immunity. The differences between these two approaches to immunity are not always black and white, but can be described in general terms with regard to immunological memory. Adaptive immunity displays this type of memory, and mounts a more intense response to pathogens upon second and subsequent exposures.
Within adaptive immunity, the system is further divided into humoral immunity and cell-mediated immunity. We can say that antibodies are the primary mediators of the former, while CD8 T-cell based cytotoxicity is the mediator of the latter.
CD4 T-cells, unlike their CD8 counterparts, are involved in both the humoral and cell-mediated arms of adaptive immunity. These CD4 cells drive isotype switching, a process that changes the types of antibodies produced after initial exposure to a pathogen to increase their molecular affinity. Additionally, CD4 cells promote the activity of macrophages to directly digest invading pathogens.
After isotype switching facilitates the production of new serum antibody types by B-cells, an experiment shows that antibodies bind more tightly to pathogens. The researcher conducting the experiment concludes that these new antibodies are more efficient at interrupting infection than were the antibodies produced immediately following initial exposure to the pathogen. Which of the following is the most likely?
The question specifies that the antibodies in question are serum antibodies, while IgA is primarily an antibody type secreted into luminal environments. As a result, we can conclude that IgA is not likely to be involved at all in this experiment. Beyond this, you must know that IgM is the type of antibody that is produced upon initial pathogen exposure. After CD4 cells facilitate isotype switching, IgG is produced and demonstrates more robust binding.
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The human immune system is organized along two broad arms: innate immunity and adaptive immunity. The differences between these two approaches to immunity are not always black and white, but can be described in general terms with regard to immunological memory. Adaptive immunity displays this type of memory, and mounts a more intense response to pathogens upon second and subsequent exposures.
Within adaptive immunity, the system is further divided into humoral immunity and cell-mediated immunity. We can say that antibodies are the primary mediators of the former, while CD8 T-cell based cytotoxicity is the mediator of the latter.
CD4 T-cells, unlike their CD8 counterparts, are involved in both the humoral and cell-mediated arms of adaptive immunity. These CD4 cells drive isotype switching, a process that changes the types of antibodies produced after initial exposure to a pathogen to increase their molecular affinity. Additionally, CD4 cells promote the activity of macrophages to directly digest invading pathogens.
A scientist is conducting an experiment with a bacterial cell that stimulates an antibody response in mice. The scientist is able to isolate the particular region of the bacterial cell that generates the response and binds to the antibody. This portion of the bacterial cell is best described as the __________.
The epitope is the region of a target cell to which an antibody binds. The remaining choices are all structural regions of the antibody itself, as opposed to the target cells to which an antibody binds.
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The immune system has two components: innate (non-specific, which is internal to someone's system from birth) and adaptive (which responds to specific antigens and develops over time). Part of the adaptive system is the humoral system, which involves antibodies. How does the humoral antibody-mediated system work?
Skin is an innate external defense barrier and does not involve antibodies. Inflammation and antimicrobial proteins are innate internal defense mechanisms, and are not pathogen-specific. T-lymphocytes are adaptive cell-mediated defense mechanisms. The humoral system, though, is part of the adaptive immune system, which delivers antibodies through blood to fight antigens extracellularly.
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Which antibody is able to cross the placenta?
IgG is the only class of immunoglobulin that is able to cross the placenta. This is important as this immunoglobulin is able to provide passive immunity to the unborn fetus
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MHC I is found on which cell types?
MHC I is found on all nucleated cells and presents antigens to cytotoxic T lymphocytes. These cytotoxic T cells contain CD8 receptors, which binds to MHC I. MHC II cells are found on B-lymphocytes and antigen presenting cells only. MHC II presents antigens to helper T cells, which contain CD4 receptors.
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What type of immunoglobulin plays an important role in the allergic response?
IgE is able to bind via the (fragment crystallizable) Fc region to mast cells and basophils. This binding allows these cells to release their granule contents involved in many allergic reactions.
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Immunoglobin M (IgM) __________.
IgM is the first antibody produced during the primary immune response. It is the only immunoglobulin whose shape is a pentamer. IgG is the most abundant immunoglobulin class in the blood and tissue and has the ability to cross the placenta. IgE binds to basophils and mast cells and is involved in the allergic response.
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A patient has A positive blood type. What type of blood can this patient receive?
For any recipient, we must consider what antibodies they have. A patient with A positive blood has the following antibodies: anti-B For any donor, we must consider what antigens they have. The donor cannot have an antigen that matches the recipient's antibodies, or else agglutination will occur. Therefore, any B blood types will result in agglutination. The O positive person only expresses the Rh antigen, and the recipient does not express this antibody. No agglutination will occur.
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A patient has AB positive blood. Which of the following blood types, if transfused, would cause agglutination?
An AB positive patient is known as a universal recipient because they can receive blood from any blood type. The recipient's antibodies are what will attack foreign antigens. Type AB positive patients produce no antibodies, because any antibody produced would attack their own antigens, causing agglutination. Because type AB patients patients do not produce antibodies, they cannot attack any antigens and they can receive any blood type.
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A patient with O negative blood needs a transfusion. What blood type can they safely receive?
A person with O negative blood is known as the universal donor because their blood cells completely lack antigens. This means their blood cannot be recognized as foreign by a donor. For blood transfusions, we must keep in mind the recipient's antibodies. For an O negative recipient, he/she produces A and B antigens, and Rh antigens if they have been previously exposed to Rh positive blood. That means they cannot accept blood from donors with A, B or possibly Rh positive blood. They must receive O negative blood only.
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Which of the following statements are true?
I. An Rh negative patient can receive Rh positive blood once without a reaction, but any subsequent exposure will result in agglutination
II. An Rh positive patient can receive Rh negative blood once without a reaction, but any subsequent exposure will result in agglutination
III. An Rh negative patient can receive Rh negative blood once without a reaction, but any subsequent exposure will result in agglutination
Rh negative people are not born with Rh antibodies. After exposure to Rh positive blood, the Rh negative patient will begin producing Rh antibodies. Any subsequent exposure will cause agglutination. This has applications in childbirth, if there mother is Rh negative, and the baby is Rh positive. It is possible for the baby's blood to come in contact with the mother's (especially during childbirth). Neither the baby nor the mother are at risk, however, if the mother has another baby that is Rh positive, the mother will have antibodies from when she first encountered Rh positive blood from the previous baby. This may cause harm to the second (and any subsequent) Rh positive babies.
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Which of the following correctly lists the antibodies and antigens an person with A positive blood has?
Blood antigens are the protein markers on the surface of red blood cells. On an A positive red blood cell, there is the A marker (antigen) and the Rh marker (antigen). Antibodies are found in the blood plasma, and these bind to foreign antibodies to cause agglutination. People produce antibodies for the antigens they do not have (Rh antibodies are only made after exposure to Rh positive blood). An A positive person will express the B antibody.
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Which of the following correctly lists the antibodies and antigens an person with AB positive blood has?
Blood antigens are the proteins markers on the surface of a red blood cell. On an AB positive red blood cell, there is the A marker (antigen), the B marker (antigen) and the Rh marker (antigen). Antibodies are found in the blood plasma, and these bind to foreign antibodies to cause agglutination. People produce antibodies for the antigens they do not have (Rh antibodies are only made after exposure to Rh positive blood). An AB positive person will not have any antibodies, otherwise they would bind to their own red blood cells and cause agglutination.
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Which of the following are true, assuming A, B, O blood type compatibility?
I. An Rh positive patient cannot receive blood from an Rh negative donor
II. An Rh negative patient cannot receive blood from an Rh positive donor
III. An Rh negative patient can only receive blood from an Rh negative donor
We must first assume the two people are A, B, O compatible (ie., both patients are type A). An Rh negative person is negative because they lack the Rh antigen. An Rh positive person does not produce any Rh antibodies or else they would attack their own blood. Therefore, there is no antigen to attack and no antibodies to attack with, so agglutination will not occur.
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Which of the following attaches directly to pathogens to mark them for destruction?
Antibodies are produced by plasma cells (mature B-cells) with specific binding affinity for surface proteins that have been presented by antigen-presenting cells, like dendritic cells and macrophages. Once the plasma cell is stimulated by the presence of the specific antigen, it increases production of its antibody. These antibodies enter the blood and bind the antigen molecules on the surface of the pathogen cell. Cytotoxic T-cells and cytokines can then interact with the antibodies to initiate lysis of the infected cell or pathogen.
Compare your answer with the correct one above
Which of the following statements is true?
It helps to think of antigens and antibodies like a lock and key: they are highly specific for one another. B-lymphocytes create only one type of antibody. When this antibody attaches to an antigen presented by a macrophage or antigen-presenting cell, the B-lymphocyte will differentiate with the help of a helper T-cell. The result is replication of the B-lymphocyte to produce more of the same antibody from plasma cells and generate memory B-cells to easily respond in the event of a second infection by the pathogen.
Compare your answer with the correct one above
The human immune system is organized along two broad arms: innate immunity and adaptive immunity. The differences between these two approaches to immunity are not always black and white, but can be described in general terms with regard to immunological memory. Adaptive immunity displays this type of memory, and mounts a more intense response to pathogens upon second and subsequent exposures.
Within adaptive immunity, the system is further divided into humoral immunity and cell-mediated immunity. We can say that antibodies are the primary mediators of the former, while CD8 T-cell based cytotoxicity is the mediator of the latter.
CD4 T-cells, unlike their CD8 counterparts, are involved in both the humoral and cell-mediated arms of adaptive immunity. These CD4 cells drive isotype switching, a process that changes the types of antibodies produced after initial exposure to a pathogen to increase their molecular affinity. Additionally, CD4 cells promote the activity of macrophages to directly digest invading pathogens.
After isotype switching facilitates the production of new serum antibody types by B-cells, an experiment shows that antibodies bind more tightly to pathogens. The researcher conducting the experiment concludes that these new antibodies are more efficient at interrupting infection than were the antibodies produced immediately following initial exposure to the pathogen. Which of the following is the most likely?
The question specifies that the antibodies in question are serum antibodies, while IgA is primarily an antibody type secreted into luminal environments. As a result, we can conclude that IgA is not likely to be involved at all in this experiment. Beyond this, you must know that IgM is the type of antibody that is produced upon initial pathogen exposure. After CD4 cells facilitate isotype switching, IgG is produced and demonstrates more robust binding.
Compare your answer with the correct one above