Immunology - Chapter 1 - 4 MCQ
Chemokine receptors form complexes with _____ after binding to their ligands. inflammasome components pro-IL-1\beta potassium channels GTP-binding proteins tertiary granules.
GTP-binding proteins
Which of the following is FALSE regarding the function of barriers in the immune system? Barriers are a line of defense encountered by a pathogen before the innate and adaptive immune system Genetic changes are a type of barrier defense that ensures pathogens are eliminated from the body Pathogens enter the body through several places that are covered by skin Skin acts as both a physical and chemical barrier against pathogens Mucus is thick fluid layer containing glycoproteins, proteoglycans and enzymes that help to prevent pathogen infection
Genetic changes are a type of barrier defense that ensures pathogens are eliminated from the body
All of the following are true of MyD88 except _____. It binds to the TIR domains of all Toll-like receptors except TLR3. It binds to IRAK4, a protein kinase, causing the kinase to phosphorylate itself. It is an adaptor protein with similar function to TRIF. A genetic deficiency of MyD88 causes the disease X-linked ectodermal dysplasia and immunodeficiency.
A genetic deficiency of MyD88 causes the disease X-linked ectodermal dysplasia and immunodeficiency. A genetic deficiency of NEMO (IKKg x-chromosome gene) results in susceptibility to bacterial infections because NFkB is impaired
The following cytokines activate NK cells early in the course of a viral infection with the exception of _____. IFN-\alpha IFN-\beta IFN-\gamma IL-12 IL-15.
IFN-\gamma
All of the following induce fever except _____. IL-12 IL-6 IL-1 TNF-\alpha.
IL-12 Signals for activation of NK cells
Which of the following is NOT a component of the assembled inflammasome complex? NRLP3 Procaspase Adaptor protein IL-1β
IL-1β
Part of the inspiration for discovering the process of vaccination was because Edward Jenner noted that milkmaids in rural England were less likely to contract the deadly disease of smallpox. Why was this the case? It is a mystery to this day why milkmaids don't suffer from smallpox The milk from cows contains antibodies against smallpox If milkmaids were exposed to cowpox, they would become immune to smallpox Milkmaids were exposed to smallpox patients less often than most of the English population because they lived in rural areas
If milkmaids were exposed to cowpox, they would become immune to smallpox
All of the following statements are correct regarding \alpha2-macroglobulin except _____. it binds covalently to its target via a thioester bond it possesses a bait region to lure its target it undergoes a conformational change that enables it to enshroud the target when bound to its target it is cleared from the circulation by hepatocytes, fibroblasts, and macrophages bearing receptors specific for the complex its target is the membrane-attack complex on human cells.
its target is the membrane-attack complex on human cells.
Which of the following pairs of associations is mismatched? large granular lymphocyte: T cell megakaryocyte: platelet B cell: plasma cell monocyte: macrophage myeloid progenitor: neutrophil.
large granular lymphocyte: T cell
Immune cells within the lymphatic circulation are directly deposited into which of the following anatomical sites so that the cells may reenter the bloodstream? right aorta left subclavian vein left carotid artery high endothelial venule hepatic vein.
left subclavian vein
In common with Toll-like receptors, NOD-like receptors also contain _____ that is/are used for pathogen-recognition of microbial ligands. caspase-recruitment domains (CARD) Toll interleukin 1 receptor (TIR) domain variable extracellular domain leucine-rich repeat regions (LRRs) C-type lectin domain (CTLD).
leucine-rich repeat regions (LRRs)
A term generally used to describe all white blood cells is _____. hematopoietic cells myeloid progenitor dendritic cells monocytes leukocytes.
leukocytes
Scavenger receptor SR-B recognizes _____. lipopolysaccharides teichoic acid filamentous hemagglutinin CpG-rich bacterial DNA lipids.
lipids
Which of the following pairs is mismatched? lymphocytes: innate immune response natural killer cell: kills virus-infected cells macrophage: phagocytosis and killing of microorganisms erythrocyte: oxygen transport eosinophil: defense against parasites.
lymphocytes: innate immune response
The lectin pathway of complement activation is induced by _____. C-reactive protein antibodies bound to pathogens mannose-binding lectin iC3Bb terminal components of the complement pathway.
mannose-binding lectin
Which of the following pairs is matched CORRECTLY? neutrophils: more abundant than erythrocytes (RBCs) natural killer cell: phagocytosis of viruses macrophage: killing of infected host cells megakaryocyte: generation of platelets eosinophil: oxygen transport
megakaryocyte: generation of platelets
The progenitors of macrophages are _____. megakaryocytes dendritic cells monocytes neutrophils erythrocytes M cells.
monocytes
Macrophages bear on their surface receptors for all of the following except _____. (Select all that apply). mannose glucans C3b muramyl dipeptide lipopolysaccharide lipoteichoic acid CpG-rich bacterial DNA.
muramyl dipeptide = NOD2 CpG-rich bacterial DNA = TLR9 Lectins: Mannose & Glucan & CD14 recognizes LPS SR-A1: Lipoteichoic acid (neg. charged) SRE2 (dectin): Fungal or yeast carbohydrate
Another name for a large granular lymphocyte is a _____. plasma cell helper T cell monocyte natural killer cell eosinophil.
natural killer cell
The most abundant type of leukocyte in human peripheral blood is the _____. eosinophil basophil neutrophil monocyte lymphocyte.
neutrophil
Which of the following pairs is mismatched? natural killer cell: kills virus-infected cells macrophage: phagocytosis and killing of microorganisms erythrocyte: oxygen transport eosinophil: defense against parasites neutrophils: adaptive immune response
neutrophils: adaptive immune response
All of the following are examples of chemical barriers of innate immunity except _____. lactic acid normal microbiota lysozyme fatty acids proteases.
normal microbiota
Effector cells that secrete antibodies are known as _____. natural killer cells cytotoxic T cells helper T cells M cells plasma cells regulatory T cells.
plasma cells
The importance of CD59 (also known as protectin) is to _____. promote the speed of complement activation by protecting C3 convertase C3bBb from proteolytic degradation prevent the recruitment of C9 dissociate the components of the alternative C3 convertase prevent the attachment of C3b to host cell surfaces inhibit the anchoring of C5b, C6, and C7 to host cell surfaces.
prevent the recruitment of C9
An adaptor protein in the inflammasome is required to link _____ to the NOD-like receptor NLRP3. MyD88 procaspase-1 RIPK2 TAKI IKK.
procaspase-1
Plasmacytoid dendritic cells _____. (Select all that apply.) detect viral infection by using TLR4 produce large amounts of the type I interferons when activated are found exclusively in the blood make up 10% of circulating leukocytes have a cytoplasmic morphology resembling that of antibody-producing plasma cells.
produce large amounts of the type I interferons when activated have a cytoplasmic morphology resembling that of antibody-producing plasma cells.
The function of uterine NK cells (uNK) is to _____. kill virus-infected cells secrete growth factors that promote blood vessel growth to supply the placenta activate resident macrophages by secreting inflammatory cytokines secrete 1000 times more type I interferon than other cells to protect the fetus from viral infection.
secrete growth factors that promote blood vessel growth to supply the placenta
The _____ is (are) the lymphoid organ(s) that filter(s) the blood. spleen tonsils Peyer's patches appendix adenoids.
spleen
Immediately after engagement of NK-cell Toll-like receptors, the NK cell _____. discharges cytotoxic granules ligates IL-12R\beta1 and IL-12R\beta 2 synthesizes and secretes IL-15 synthesizes and secretes IL-12 synthesizes and secretes Interferon gamma
synthesizes and secretes Interferon gamma
On the heavy-chain immunoglobulin gene locus, recombination signal sequences flank _______ of the V segment, _______ of the D segment, and _______ of the J segment. the 5′ side; both sides; the 3′ side the 5′ side; the 5′ side, the 5′ side the 3′ side; both sides; the 3′ side both sides; both sides; both sides the 3′ side; both sides; the 5′ side.
the 3′ side; both sides; the 5′ side.
Which of the three complement pathways becomes activated soonest after an initial infection? the classical pathway the lectin pathway the alternative pathway.
the alternative pathway
The main initiating factor for the start of complement activation early in an infection is ...... the binding of complement to phosphocholine the mannose sugars on the pathogen surface the nucleophilic environment on the pathogen surface the formation of the membrane attack complex
the nucleophilic environment on the pathogen surface
Which of the following is not associated with mucosal surfaces? mucus-secreting goblet cells lysozyme M cells white pulp beating cilia.
white pulp
Which of the following statements about the production and use of monoclonal antibodies is incorrect? Production of monoclonal antibodies requires a purified form of antigen. A monoclonal antibody has specificity for only one epitope of an antigen. B cells are fused with a tumor cell called a myeloma, to immortalize the resulting hybridoma. Monoclonal antibodies made in mice have limited therapeutic potential. Humanized monoclonal antibodies reduce complications associated with using mouse monoclonal antibodies.
Production of monoclonal antibodies requires a purified form of antigen.
After recognizing its ligand, a NOD receptor interacts with a signaling protein called _____, which is a serine-threonine kinase that phosphorylates TAKI. CARD NLRP3 RIPK2 MARCO SR-A.
RIPK2
Which of the following statements is false? During human development, hematopoiesis takes place at different anatomical locations. The hematopoietic stem cell gives rise to white blood cells, but a different stem cell is the progenitor of red blood cells. Hematopoietic stem cells are self-renewing. Platelets participate in clotting reactions to prevent blood loss. Megakaryocytes do not circulate and reside only in the bone marrow.
The hematopoietic stem cell gives rise to white blood cells, but a different stem cell is the progenitor of red blood cells.
Which of the following is TRUE regarding the lymph system? Blood is part of the lymph system The lymph node is the site of production of neutrophils The fluid that passes through the lymph vessels is pumped by the action of the heart The lymph nodes serve as the site where antigens stimulate the immune system
The lymph nodes serve as the site where antigens stimulate the immune system
All of the following are correct in reference to type I interferons except _____. Type I interferons inhibit the replication of viruses. In the presence of type I interferons, virus-infected cells undergo cell-surface changes that render them more susceptible to attack by NK cells. Not only can most cells synthesize type I interferons, but they can also respond to them. The receptor for type I interferons is abundant in the cytosol. Type I interferons function in autocrine and paracrine fashions. Type I interferons promote NK-cell proliferation and differentiation into cytotoxic cells.
The receptor for type I interferons is abundant in the cytosol.
Why does an infected tissue site swell during inflammation? Tissues swell because the red blood cells are attacking the bacteria Tissues swell because of increased permeability of capillaries resulting in fluid accumulation Tissues swell because the amount of bacteria present in the wound is increasing Tissues swell because the one way valves of the lymph system are permanently closed All of the above
Tissues swell because of increased permeability of capillaries resulting in fluid accumulation
What does it mean to humanize a mouse monoclonal antibody? (Assume you are starting with the mouse antibody and making changes TO the mouse antibody) To remove the Fc region of the mouse monoclonal antibody To exchange amino acids in the constant parts of the mouse antibody with amino acids found in human antibodies. The order of the amino acids does NOT matter. To exchange amino acids in the constant parts of the mouse antibody with amino acids found in human antibodies. The order of the amino acids does matter. To exchange amino acids in the variable parts of the mouse antibody with amino acids found in human antibodies. The order of the amino acids does NOT matter. To exchange amino acids in the variable parts of the mouse antibody with amino acids found in human antibodies. The order of the amino acids does matter.
To exchange amino acids in the constant parts of the mouse antibody with amino acids found in human antibodies. The order of the amino acids does matter.
The enzyme responsible for recombining V, D, and J segments during somatic recombination is called V(D)J recombinase terminal deoxynucleotidyl transferase exonuclease DNA polymerase DNA ligase.
V(D)J recombinase
hich of the following is the predominant route by which pathogens are brought from a site of infection into a lymph node? efferent lymphatics artery vein afferent lymphatics high endothelial venule.
afferent lymphatics
All of the following acute-phase proteins increase in concentration in the plasma during inflammation with the exception of _____. albumin serum amyloid A protein fibrinogen C3 mannose-binding lectin.
albumin
_____ are soluble complement fragments that mediate localized and systemic inflammatory responses. cryptdins defensins anaphylatoxins selectins C-reactive proteins.
anaphylatoxins
In contrast with leader peptides and the C regions, the V regions in immunoglobulin heavy-chain genes encode hydrophobic amino acids that anchor the immunoglobulin chains to B-cell membranes comprise the smallest number of gene segments in the human immunoglobulin loci are composed of V, D, and J gene segments that must undergo gene rearrangement to generate a transcribable exon do not undergo somatic hypermutation are not subject to allelic exclusion.
are composed of V, D, and J gene segments that must undergo gene rearrangement to generate a transcribable exon
The name given to cytokines that recruit cells to move towards areas of inflammation is _____. chemokines caspase-recruitment domains (CARDs) inflammakines adhesion molecules pyrogens.
chemokines
Another term commonly used to describe hypervariable loops is multivalency framework regions hinge region complementarity-determining regions signal joint.
complementarity-determining regions Located with a V domain and varies greatly between different antibodies
When effector lymphocytes secrete _____, an inflammatory response ensues. lysozyme defensins lymph sebum cytokines.
cytokines
The membrane-bound proteins on healthy human cells that prevent complement activation is/are _____. decay-accelerating factor and membrane cofactor protein factor B, factor H and factor I the membrane cofactor protein the membrane defending complex decay-accelerating factor and factor H
decay-accelerating factor and membrane cofactor protein
The membrane-bound proteins on human cells that dissociate and inactivate alternative C3 convertase to avoid complement activation are _____. factor B and factor H factor H and factor I factor B and factor I decay-accelerating factor and factor H decay-accelerating factor and membrane cofactor protein.
decay-accelerating factor and membrane cofactor protein.
An example of an antimicrobial peptide that protects epithelial surfaces from pathogens is _____. glycoprotein defensin proteoglycan lysozyme sebum.
defensin
Primary lymphoid tissues are the sites where lymphocytes _______, whereas secondary lymphoid tissues are the sites where lymphocytes _______. are stimulated; develop and mature encounter pathogens; undergo apoptosis develop and mature; become stimulated undergo clonal selection; differentiate from hematopoietic stem cells die; are phagocytosed after death.
develop and mature; become stimulated
A bacterium that causes a common disease in a population that has been previously exposed to it is called _____. opportunistic resistant commensal endemic attenuated
endemic
The thin layer of cells that makes up the interior lining of the blood vessels is called the _____. mucosa epithelium endothelium connective tissue lymphoid tissue.
endothelium
Which of the following does not describe the actions of the coagulation system? blood clot formation enhancement of dissemination of microbes into lymphatics and bloodstream decrease in blood loss and fluid into interstitial spaces in tissues release of inflammatory mediators by platelets wound healing.
enhancement of dissemination of microbes into lymphatics and bloodstream
Soluble effector molecules are effective when encountering pathogens in/on _____. (Select all that apply.) extracellular spaces cytoplasm epithelial surfaces interstitial spaces vesicular compartments lymph.
extracellular spaces epithelial surfaces interstitial spaces lymph
The plasma proteins that counteract the activity of factor P by inactivating C3 convertase through the cleavage of C3b are _____. factor B and factor H factor H and factor I factor B and factor I decay-accelerating factor and factor H decay-accelerating factor and membrane cofactor protein.
factor H and factor I
Which of the following is mismatched? 100-110-amino-acid motif: immunoglobulin domain discontinuous epitope: amino acids that are separated in the protein chain but come together in the folded protein heavy-chain classes: IgG, IgA, IgM, IgE, IgD multivalent antigen: antigen that carries several epitopes of the same or different specificity four C domains: IgM and IgD.
four C domains: IgM and IgD. The heavy chain of IgG has four domains
Spherical regions in lymph nodes containing areas that are packed densely with proliferating B cells are called _____. efferent vessels germinal centers red pulp zones periarterial lymphoid sheaths medullary sinuses.
germinal centers
The five isotypes of immunoglobulin differ from each other in their _____: light-chain constant regions heavy-chain constant regions light-chain variable regions heavy-chain variable regions heavy-chain variable and constant regions.
heavy-chain constant regions Heavy chain constant region is the most conserved region of the molecule, which interacts with other immune-system components
Which of the following does not describe defensins? highly conserved with few variants contain a large proportion of arginine residues contain three intra-chain disulfide bonds amphipathic, with hydrophobic and hydrophilic regions disrupt pathogen membranes by penetrating them and disrupting their integrity.
highly conserved with few variants
The pH of the phagosome increases following phagocytosis because _____. the microbe delivers a significant number of hydroxyl ions in its cytosol that are released upon membrane disruption hydrogen ions are eliminated by the activity of NADPH oxidase and superoxide dismutase azurophilic granules deliver alkaline substances catalase consumes hydrogen ions once activated.
hydrogen ions are eliminated by the activity of NADPH oxidase and superoxide dismutase
Which of the following is the soluble form of C3 convertase of the alternative pathway of complement activation? iC3 iC3b C3b iC3Bb C3bBb.
iC3Bb
The ligand for CR3 and CR4 formed by the cleavage of C3b by the combined action of factors H and I is called _____. C3bBb C3a C3b2Bb iC3b C5b.
iC3b CR3 and CR4 can bind to iC3b, LPS, HA, and lipophosphoglycan
The highest degree of diversity resulting from somatic recombination is concentrated ____________ of the VH and VL domains, whereas the point mutations caused by somatic hypermutation are found ____________. in CDR3; throughout the V region in CDR3; in CDR1 and CDR2 of VH and VL domains in CDR1 and CDR2; in CDR3 in CDR1 and CDR2; throughout the V region in all three CDRs; in C regions.
in CDR3; throughout the V region CDR = Complementarity Determining Regions = Hypervariable Loops = Located within a V domain and varies greatly between antibodies
Which of the following are characteristics of innate immunity: inflammation improvement in recognition of the pathogen during the response fast response highly specific for a particular pathogen cytokine production.
inflammation fast response cytokine production.
The first line of defense against microorganisms that infect the body is referred to as _____. opportunistic immunity innate immunity adaptive immunity primary immunity central immunity.
innate immunity
Which of the following pairs is mismatched? innate immunity: highly specialized defenses secondary immune response: immunological memory hematopoiesis: bone marrow phagocytosis: uptake and killing of microbes lymphocyte recirculation: continuous transport between blood and lymph.
innate immunity: highly specialized defenses
What is FALSE regarding the anaphylatoxins? Anaphylatoxins includes the C2a complement factor Anaphylatoxins lead to degranulation of mast cells Anaphylatoxins increase vascular permeability Anaphylatoxins are released during the process of complement fixation Anaphylatoxins are small fragments derived from a larger complement protein
Anaphylatoxins includes the C2a complement factor
Which of the following is an example of bacterial mimicry? Bacteria produce antibody directed against immune system cytokines Bacteria cover their surfaces with sialic acid so that Factor H becomes attached to the bacteria Bacteria inhibit competing virus pathogens by secreting interferons Bacteria express BCRs on their cell surface to prevent binding of complement
Bacteria cover their surfaces with sialic acid so that Factor H becomes attached to the bacteria
Production by the patient of antibodies against therapeutic mouse monoclonal antibodies is the major limitation for their use in humans. These human anti-antibodies are directed against the _____ of the mouse antibody. V regions D regions C regions J regions MC regions.
C regions
All of the following complement proteins help form a pore in the pathogen's membrane except _____. C3b C5b C6 C7 C8 C9.
C3b
The C3 convertase that functions in the lectin pathway of complement activation consists of _____. C3bBb C3b2a C4b2a C4b2b C3b2Bb.
C4b2a
Which of the following polymerizes to form a transmembrane channel that compromises the integrity of cell membranes? C5 C6 C7 C8 C9.
C9
_____ is/are needed to minimize the damaging effects to neighboring host cells during a respiratory burst. Catalase activity Complement control proteins NADPH oxidase activity Neutrophil mobilization Superoxide dismutase activity.
Catalase activity
Which of the follow is FALSE regarding the complement system? Complement components are synthesized in the liver Complement components are synthesized in a zymogen state Complement components are activated by phosphorylation The complement proteins are transported around the body by the blood
Complement components are activated by phosphorylation
_____ act as cellular messengers by delivering degraded pathogens to lymphoid organs. Plasma cells Dendritic cells Large granular lymphocytes Mast cells Basophils.
Dendritic cells
The five classes (isotypes) of immunoglobulins comprise IgA, IgD, IgE, IgG, IgM IgA, IgC, IgD, IgE, IgG IgA, IgD, IgE, IgH, IgM IgA, IgD, IgE, IgG, IgK IgA, IgD, IgE, IgG, IgS.
IgA, IgD, IgE, IgG, IgM IgA: Neutralization Opsonin Complement activation Most abundant in mucosal secretion More made in body that any other antibody IgD: Sensitization of basophils IgE: Mast cell sensitization Sensitization of basophils Least abundant in serum IgG: Neutralization, Opsonization, Sensitization for NK cells, Complement activation Transport across placenta Most abundant in serum Sensitiation of mast cells Composed of subclasses that differ in ability to activate complement and induce inflammation IgM: Complement activation
Indicate which of the following statements is false. (Select all that apply.) Immunoglobulin heavy- and light-chain loci are encoded on the same chromosome. Light chains contain V and J segments, whereas heavy chains contain V, D, and J segments. The Vκ gene segments are duplicated in about 50% of the human population. All immunoglobulin loci include a leader sequence. On the heavy-chain locus, V rearranges to D first, and then J joins the combined VD sequence. Immunoglobulin heavy-chain loci undergo two rounds of somatic recombination, whereas light-chain loci undergo only one.
Immunoglobulin heavy- and light-chain loci are encoded on the same chromosome. On the heavy-chain locus, V rearranges to D first, and then J joins the combined VD sequence. Immunoglobulin heavy- and light-chain loci are encoded on different chromosomes On the heavy-chain locus, D rearranges to J first, and then V joins the recombined DJ sequence
Which of the following statements regarding immunoglobulins is correct? Immunoglobulins make up five classes (or isotypes) called IgA, IgD, IgE, IgG, and IgM. Regardless of their isotype, immunoglobulins all have the same effector function. Antibodies consist of four identical heavy chains and four identical light chains. Peptide bonds hold the heavy and light chains together. The constant regions make up the antigen-binding site.
Immunoglobulins make up five classes (or isotypes) called IgA, IgD, IgE, IgG, and IgM. Immunoglobulins have different effector function Antibodies consist of five different heavy chains and two different light chains Disulfide bonds hold the heavy and light chains together The variable region makes up the antigen-binding site
Which of the following is a mismatched property or definition? Hematopoiesis - process occurring in the bone marrow Innate immunity - highly specialized defense system Adaptive immunity - involvement of B cells and T cells Innate immunity - occurs before adaptive immunity in defense against pathogens Adaptive immunity - associated with memory lymphocytes
Innate immunity - highly specialized defense system
The spleen differs from other secondary lymphoid organs in which of the following ways? It does not contain T cells. It filters blood as well as lymph. It is populated by specialized cells called M cells. It receives pathogens via afferent lymphatic vessels. It has no connection with the lymphatics.
It has no connection with the lymphatics.
Modern immunology and vaccination has interesting origins from the English countryside and Edward Jenner. Which of the following is FALSE regarding the history of modern immunology and vaccination? Edward Jenner is credited with "inventing" vaccination Edward Jenner tested the concept of vaccination by inoculating a young child Smallpox was officially eradicated in the 1970s due to a massive global vaccination campaign The term vaccination originated from the fact that Edward Jenner was working with the vaccinia virus Jenner conceived the concept of vaccination because he noticed milk maids were more likely to be infected by smallpox
Jenner conceived the concept of vaccination because he noticed milk maids were more likely to be infected by smallpox
Which of the following is NOT a characteristic of the adaptive immune response? The use of memory lymphocytes during an infection in which the pathogen causing the infection is seen for the second time Clonal selection of a B-cell which has a BCR that can bind to an antigen present on the pathogen Killing of virus-infected cells by NK cells Maturation of a B cell into a plasma cell in the lymph node
Killing of virus-infected cells by NK cells The balance of NK cells to dendritic cells is a factor in controlling the transition to adaptive immunity More Adaptive Immunity = Less NK Cells; More Dendritic Cells
Identify the incorrect statement regarding hematopoiesis. Hematopoiesis is a continuous process that occurs throughout one's lifetime. The location for hematopoiesis differs with age. Self renewal is necessary to replenish the supply of hematopoietic stem cells. Most hematopoiesis occurs in the bone marrow after birth. Leukocytes, but not erythrocytes, must go through hematopoiesis in order to develop.
Leukocytes, but not erythrocytes, must go through hematopoiesis in order to develop.
Which of the following statements is correct concerning membrane-coding (MC) exons of immunoglobulin genes? MC exons are located upstream (5′) of the constant-domain exons. MC exons code for amino acids that anchor and stabilize the light chain to the membrane of B cells. MC exons specify transmembrane hydrophobic amino acids that associate with the B-cell membrane. MC exons are removed from primary RNA transcripts as a consequence of alternative mRNA splicing when secreted antibodies are produced by plasma cells. Somatic hypermutation causes alteration in the coding sequence of MC exons.
MC exons specify transmembrane hydrophobic amino acids that associate with the B-cell membrane.
Which of the following statements are correct? Macrophages are granulocytes. Macrophages derive from monocytes. Macrophages are non-phagocytic. Macrophages reside in the tissues. All of the above statements are false.
Macrophages derive from monocytes. Macrophages reside in the tissues.
Which of the following is TRUE regarding hematopoiesis? NK cells are most related to T cells compared to other immune cells based on their stem cell precursor origins Hematopoietic stem cells do NOT self-renew but are long-lived so they can differentiate into other cell types All human cells are derived from the hematopoietic stem cell The secondary lymphoid organs and tissue are the major site of hematopoiesis
NK cells are most related to T cells compared to other immune cells based on their stem cell precursor origins
Which of the following statements regarding neutrophils is false? Neutrophils are mobilized from the bone marrow to sites of infection when needed. Neutrophils are active only in aerobic conditions. Neutrophils are phagocytic. Neutrophils form pus, which comprises dead neutrophils. Dead neutrophils are cleared from sites of infection by macrophages.
Neutrophils are active only in aerobic conditions.
TLRs are a large family of pathogen-sensing receptors. Which of the following is TRUE? They only detect viral pathogens They are only found in intracellular vesicles They are restricted to NK cells and not found on most other immune cells They are a key molecule of the adaptive immune system None of the above
None of the above
Which of the following pairs is mismatched? monocyte progenitor: macrophage erythroid progenitor: megakaryocyte myeloid progenitor: neutrophil lymphoid progenitor: natural killer cell. None of the above is mismatched.
None of the above is mismatched.
Junctional diversity during gene rearrangement results from the addition of switch region nucleotides P and N nucleotides V, D, and J nucleotides recombination signal sequences mutations in complementarity-determining regions.
P and N nucleotides
Which of the following therapies is the most promising but still experimental approach to eliminate a Clostridium difficile infection? Influenza vaccination Broad spectrum antibiotic that targets a wide variety of microbial species Intravenous administration of polyclonal antibodies against the Clostridium difficile bacteria Performing a fecal transplant to repopulate the gastrointestinal flora Hydration to treat the dehydration caused from diarrhea
Performing a fecal transplant to repopulate the gastrointestinal flora
Which of the following statements is TRUE regarding Reg3G? The presence of commensal bacteria decreases the production of Reg3G Reg3G binds to complement on the cell surface of pathogens Reg3G binds to peptidoglycan in gram positive cell walls Reg3G is an antimicrobial protein prevalent in the lymph node Clostridium difficile is highly resistant to Reg3G
Reg3G binds to peptidoglycan in gram positive cell walls Produce by intestinl paneth cells when cells have been exposed to paneth cells Antimicrobial protein that binds to peptidoglycan of bacteria Commensal bacteria induce expression of Reg3G because of PAMPs
Which of the following antibody technologies, products or drugs is FALSELY described? RhoGam - a monoclonal-based drug used to prevent an attack on a fetus by the mothers antibodies Antivenin Crotalidae Polyvalent (ACP) - a horse-based serum that is generated by injecting venom from many different species of snakes Humira - a monoclonal-based drug used to treat Crohn's disease Hybridoma - a fusion of B cells with a myeloma cell Pregnancy test - an antibody-based product that is used to detect a pregnancy-related hormone
RhoGam - a monoclonal-based drug used to prevent an attack on a fetus by the mothers antibodies RhoGam is polyclonal
Cytokines help to recruit neutrophils from the blood to the infected tissue. Which of the following steps are in the correct order? Rolling adhesion, tight binding adhesion, diapedesis, homing Homing, rolling adhesion, tight binding adhesion, diapedesis Rolling adhesion, diapedesis, tight binding adhesion, homing Diapedesis, tight binding adhesion, rolling adhesion, homing
Rolling adhesion, tight binding adhesion, diapedesis, homing
Many different bacterial species build sialic acid containing structures on their surface for several different reasons. For example, the N. gonorrhoeae pathogen that causes gonorrhoea is known to have sialyated LPS on its surface which helps the bacterium escape immune system effector functions. Which of the following mechanisms lead to inhibition of immune effector function by the sialic acid component of sialyated LPS? Sialic acid will block the binding of LPS to TLR8 Sialic acid increases the binding to factor H Sialic acid binds to human cell receptors to allow adhesion of the bacteria to epithelial cells Sialic acid prevents the binding of antibodies to the bacteria
Sialic acid increases the binding to factor H
What is the best definition of germinal centers? Infected tissue containing high levels of pathogens Spherical regions in lymph nodes that are packed densely with proliferating B cells Areas of the body that contain a collection of blood vessels connected to the lymph system The area of the spleen that is involved in repairing red blood cells
Spherical regions in lymph nodes that are packed densely with proliferating B cells
The Toll-like receptor that is able to detect LPS and signal via the MyD88 pathway is _____. TLR3 TLR4 TLR5 TLR7 TLR8 TLR9.
TLR4
The α2-macroglobulin protein is capable of inactivating bacterial proteases. Which of the following is FALSE regarding α2-macroglobulin anti-protease function? The α2-macroglobulin protein undergoes a conformational change that captures proteases The "bait" within α2-macroglobulin that attracts the bacterial protease is a sugar molecule The α2-macroglobulin and will encircle the bacterial protease and the protease is covalently bound to the α2-macroglobulin
The "bait" within α2-macroglobulin that attracts the bacterial protease is a sugar molecule
