Description : Numerous antibodies can be prepared, against one antigen, each binds to unique epitopes. How is this antibody diversity generated? A- By rearrangements of the DNA encoding the variable regions of the heavy ... proteins can physically change their shape to bind different epitopes D- Both (a) and (b)
Last Answer : Both (a) and (b)
Description : Which of the following statement(s) is/are true concerning the antibody response to an invading antigen? a. All antibodies are composed of one type of heavy and one type of light protein chain b. ... stimulus d. Immunoglobulins A, D, and E play an active role in the circulating humoral response
Last Answer : Answer: a Humoral defenses consist of antibody (immunoglobulin; Ig) and complement. All Ig classes (IgM, IgG, IgA, IgE, IgD) and IgG subclasses are composed of one type (M, G, A, E, D ... exist in smaller amounts in the circulation and do not appear to play a major role as host defense components
Description : Which one of the following is NOT a function of complement? a. Stimulation of inflammation b. Stimulation of antibody formation c. Formation of membrane attack complexes d. Heightened level of phagocytosis
Last Answer : b. Stimulation of antibody formation
Description : An antigen binding site on the IgG antibody is a combination of a. One variable region from a light chain and one from a heavy chain. b. Two variable regions from two light chains. c. Two ... from two heavy chains. d. One variable region from a constant region and one from a variable region.
Last Answer : a. One variable region from a light chain and one from a heavy chain.
Description : Clonal selection includes a. Antigen-receptor binding on B cells. b. Antibody secretion recognizing same epitope as on B cell receptors. c. Differentiation of B cells into plasma cells and memory cells. d. All the above (A—C) are correct.
Last Answer : d. All the above (A—C) are correct.
Description : What is the direct cause of cell death by diphtheria toxin? A- Formation of an ion channel in the cell membrane B- Inactivation of a translational elongation factor C- Induction of apoptosis D- None of the above
Last Answer : Inactivation of a translational elongation factor
Description : The role of the M cell is to A- .trap virus in mucus and prevent entry B- induce apoptosis in virus-infected small intestinal epithelia cells C- pass bacteria or virus to underlying macrophages for ... and presentation of antigen D- they use their cilia to propel mucus out of the small intestine
Last Answer : pass bacteria or virus to underlying macrophages for processing and presentation of antigen
Description : The antigenic antibody functions of proteins by denaturation are frequently (A) Not changed (B) Changed (C) Both (A) and (B) (D) None of these
Last Answer : Answer : B
Description : The following is true of abciximab except: A. It is a monoclonal antibody against GPIIb/IIIa B. It inhibits platelet aggregation induced by a variety of platelet agonists C. It is antigenic D. It is used to reduce the risk of restenosis in patients undergoing PTCA
Last Answer : C. It is antigenic
Description : What is antigenic shift?
Last Answer : influenza A viruses can trade genetic materials with the virusesof other species. Two different strains trade or merge material, aprocess known as an antigenic shift.
Description : Which of the following cause new emerging infectious diseases? a. mutation b. recombination c. cross host ranges d. A-C are correct
Last Answer : d. A-C are correct
Description : Newly emerging viruses causing human disease can arise from a. Species Jumping. b. Mutations. c. Genetic Recombination. d. All Of The Above (A—C) Are Correct.
Last Answer : d. All Of The Above (A—C) Are Correct.
Description : Which one of the following is NOT an example of genetic recombination? a. Conjugation b. Binary fission c. Transduction d. Transformation
Last Answer : c. Transduction
Description : Which one of the following is common between prokaryotic and eukaryotic chromosomes? a. Presence or absence of introns. b. Loop or linear chromosomes. c. Genetic recombination occurrence in RNA. d. Mutations occur in the DNA.
Last Answer : d. Mutations occur in the DNA.
Description : Which of the following type of recombination does not require homologous sequences and isutilized by mobile genetic elements that move about chromosomes? A.Mutagenicrecombimation B.Site-specific recombination C.Replicative recombination D.General recombination
Last Answer : C.Replicative recombination
Description : Recombination of virus genomes occurs A- by transduction B- by transcription C- simultaneous infection of a host cell by two viruses with homologous chromosomes D- by transformation
Last Answer : simultaneous infection of a host cell by two viruses with homologous chromosomes
Description : The type of recombination that commonly occurs between a pair of homologous DNA sequences is, A- mutagenic recombination B- site-specific recombination C- replicative recombination D- general recombination
Last Answer : general recombination
Description : Which of the following type of recombination does not require homologous sequences and isimportant for the integration of viral genomes into bacterial chromosomes? A- Mutagenic recombimation B- Site-specific recombination C- Replicative recombination D- General recombination
Last Answer : Site-specific recombination
Description : The transposase gene encodes an enzyme that facilitate A- viral replication within a genome B- general recombination C- site-specific integration of transposable elements D- none of the above
Last Answer : site-specific integration of transposable elements
Description : Fibrinolytic therapy is based on activation of plasminogen, the inactive proteolytic enzyme of plasma that binds to fibrin during the formation of thrombosis. Activation of plasminogen to plasmin results ... TPA all exceed 30 minutes d. Streptokinase is significantly cheaper than urokinase or TPA
Last Answer : Answer: a, b, d Streptokinase is a bacterial protein produced by group C b-hemolytic streptococci. It is therefore antigenic in humans and can be associated with allergic reaction in ... one agent over the other. Streptokinase however, is markedly less expensive than either urokinase or TPA
Description : The alternate complement pathway doesn’t involve (A) Antigen-antibody complex (B) Complement 3 (C) Factors B and D (D) Membrane attack unit
Last Answer : Answer : A
Description : The portion of the antigen molecule which is recognized by antibody is known as (A) Hapten (B) Epitope (C) Complement (D) Variable region
Description : In the complement system; a. alternative pathway does not rely on antibody b. C1 is the first enzyme complex in the classical pathway c. both the alternative and classical pathway converge at C3 d. all above
Last Answer : all above
Description : : DiGeorge syndrome and X-linked (Bruton) agammaglobulinemia differ in the a. Type of antibody produced by the immune system. b. Lymphocytes that the body fails to produce. c. Systems affected by the respective diseases. d. Type of hypersensitivity that ensues
Last Answer : c. Systems affected by the respective diseases.
Description : Passive artificial immunity occurs in the body when a/an _____ is injected into the body or when a developing fetus receives antibodies across the placenta. a. antibody-rich serum b. antigens c. haptens d. adjuvant
Last Answer : a. antibody-rich serum
Description : Booster immunizations are used to raise the antibody level by stimulating the _____ cells to induce the secondary antibody response. a. helper T b. B c. memory d. plasma
Last Answer : c. memory
Description : In an ELISA, the primary antibody represents a. The patient‘s serum. b. The antibody recognizing the secondary antibody. c. The enzyme-linked (labeled) antibody. d. The antibodies having been washed away.
Last Answer : b. The antibody recognizing the secondary antibody.
Description : When antigens are attached to the surface of latex beads and then reacted with an appropriate antibody, a/an reaction occurs. a. Inhibition b. Agglutination c. Neutralization d. Precipitation
Last Answer : b. Agglutination
Description : Titer refers to a. The most concentrated antigen-antibody concentration showing a reaction. b. The first diluted antigen-antibody concentration showing a reaction. c. The precipitation line ... antigen-antibody reaction. d. The most dilute antigen-antibody concentration showing a reaction.
Last Answer : d. The most dilute antigen-antibody concentration showing a reaction.
Description : The _____ class of antibodies is the principal component of a secondary antibody response. a. IgM b. IgD c. IgG d. IgE
Last Answer : c. IgG
Description : This dimeric antibody class often occurs in secretions of the respiratory and gastrointestinal tracts. a. IgE b. IgM c. IgA. d. IgG
Last Answer : c. IgA.
Description : Which one of the following is NOT true of exotoxins? a. They are proteins. b. They are part of cell wall structure. c. They are released from live bacterial cells. d. They trigger antibody production.
Last Answer : d. They trigger antibody production.
Description : In which of the following case a large lattice is formed? A.Antibody is in excess B.Antigens and antibodies are in optimal proportion C.Antigen is in excess D.None of these
Last Answer : B.Antigens and antibodies are in optimal proportion
Description : Which of the following theory of antibody production is most widely accepted? A- Side chain theory B- Clonal selection theory C- Direct template theory D- Indirect template theory
Last Answer : Clonal selection theory
Description : Which of the following statements is false regarding B cells? A- B cells can undergo class switching and produce a different antibody type B- B one marrow stem cells migrate to the thymus and ... D- B cells that recognize high concentrations of antigens (self) in the absence of other signals
Last Answer : B one marrow stem cells migrate to the thymus and develop into B cells
Description : Which of the following is a cause of a secondary immunodeficiency? a. X-linked inheritance b. Deficiencies in the complement system c. Viral infection resembling self-cells d. All the above are correct
Last Answer : c. Viral infection resembling self-cells
Description : What serologicaL test requires sheep red blood cells and a preparation of antibodies that recognizes the sheep red blood ceLls? a. ELISA b. Radioimmunoassay c. Immunodiffusion d. Complement fixation test
Last Answer : d. Complement fixation test
Description : The formation of _____ by_____ directly lyses and kills pathogens. a. Membrane Attack Complexes, complement b. Inflammation, lymph nodes c. antibodies, plasma cells d. Plasma cells, B cells
Last Answer : a. Membrane Attack Complexes, complement
Description : Acquired immunity consists of humoral immunity maintained by _____ and _____, and cell-mediated immunity controlled by _____ a. T cells, complement, B cells b. T cells, Interleukin, B cells c. B cells, antibodies, T cells d. B cells, histamine, T cells
Last Answer : c. B cells, antibodies, T cells
Description : ____ becomes activated to eliminate "nonself" cells, such as virus- infected cells or cancer cells. a. Humoral immune response b. Cell-mediated immune response c. Complement d. Inflammation
Last Answer : b. Cell-mediated immune response
Description : The unique sets of proteins that present antigens on the surfaces of body cells are a. MHC proteins. b. Cytokines. c. Complement proteins. d. Immunoglobulins.
Last Answer : b. Cytokines.
Description : ________ bind to_________ on microbial invaders. a. Toll-like receptors; PAM Ps b. Mast cells; histamine c. Toll-like receptors; complement d. Macrophages; defensins
Last Answer : a. Toll-like receptors; PAM Ps
Description : Polymorphonuclear leukocytes (or PMNs) A- can be attracted to the site of an infection following activation of complement B- are derived from bone marrow stem cells C- are a type of phagocyte that can engulf and kill bacteria D- .all of the above
Last Answer : .all of the above
Description : Antibody diversity arises from (A) Gene amplification (B) Gene re-arrangement (C) Alternative splicing (D) All of these
Description : Crossing over that results in genetic recombination in higher organisms occurs between
Last Answer : Crossing over that results in genetic recombination in higher organisms occurs between A. Non- ... bivalents D. Sister chromatids of a bivalents
Description : Antigen binding site in an antibody is found between:
Last Answer : Antigen binding site in an antibody is found between: A. two light chains B. two heavy ... one light chain depending upon the nature of antigen
Description : The antigen -binding sites are present where on the antibody molecule
Last Answer : The antigen -binding sites are present where on the antibody molecule A. on light chain as well as ... region of light chain D. on heavy chain only
Description : Complement system can be activated by binding of antigen to (A) IgA (B) IgD (C) IgE (D) IgM
Last Answer : Answer : D