{ "chapter": "Immunity", "count": 100, "answerIndex": "zero-based", "notice": "Original practice items including related concept variants; not official examination questions.", "questions": [ { "id": "memory-cells", "chapter": "Immunity", "difficulty": "Foundation", "stem": "A secondary immune response is faster mainly because the first exposure produced:", "options": [ "Memory lymphocytes", "Fewer antigen receptors", "Permanent fever", "More skin" ], "answer": 0, "explanation": "Memory B and T cells persist after the primary response and expand rapidly when the same antigen returns." }, { "id": "antigen-presentation", "chapter": "Immunity", "difficulty": "Challenge", "stem": "A dendritic cell displays an extracellular pathogen-derived peptide on MHC class II. Which cell is activated most directly?", "options": [ "Red blood cell", "Helper T cell", "Platelet", "Skeletal muscle cell" ], "answer": 1, "explanation": "CD4 helper T cells recognize antigen presented on MHC class II and coordinate adaptive immune responses." }, { "id": "vaccine-response", "chapter": "Immunity", "difficulty": "Standard", "stem": "A vaccine protects without causing the full disease primarily by:", "options": [ "Eliminating all white blood cells", "Preventing every mutation", "Generating antigen-specific memory", "Replacing innate immunity" ], "answer": 2, "explanation": "Vaccination exposes the immune system to safe antigenic material, producing memory cells that support a stronger later response." }, { "id": "innate-immunity", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which feature best distinguishes innate immunity from adaptive immunity?", "options": [ "It always improves after each exposure", "It is absent at birth", "It depends only on antibodies", "It responds rapidly through broadly recognizing mechanisms" ], "answer": 3, "explanation": "Innate defences act rapidly and recognize broad danger patterns. Adaptive responses are antigen-specific and generate stronger memory." }, { "id": "immunity-skin-barrier-outcome", "chapter": "Immunity", "difficulty": "Foundation", "stem": "Intact keratinized skin covers the body surface. Which outcome follows most directly?", "options": [ "Many pathogens are prevented from entering tissues", "The bacterium becomes enclosed and digested", "Local blood flow and capillary permeability increase", "The antibody binds that antigen selectively" ], "answer": 0, "explanation": "Many pathogens are prevented from entering tissues. Tightly joined cells, dryness and antimicrobial secretions create a physical and chemical barrier." }, { "id": "immunity-skin-barrier-cause", "chapter": "Immunity", "difficulty": "Foundation", "stem": "Which change most directly explains this observation: many pathogens are prevented from entering tissues?", "options": [ "A phagocyte recognizes and surrounds a bacterium", "Intact keratinized skin covers the body surface", "Damaged tissue releases inflammatory mediators", "An antibody variable region is complementary to an antigenic epitope" ], "answer": 1, "explanation": "Many pathogens are prevented from entering tissues. Tightly joined cells, dryness and antimicrobial secretions create a physical and chemical barrier." }, { "id": "immunity-skin-barrier-mechanism", "chapter": "Immunity", "difficulty": "Foundation", "stem": "After intact keratinized skin covers the body surface, which explanation best links the change to its outcome?", "options": [ "A phagosome fuses with enzyme-containing lysosomes", "Vasodilation and endothelial changes deliver plasma proteins and leukocytes", "Tightly joined cells, dryness and antimicrobial secretions create a physical and chemical barrier", "Shape and charge complementarity permit specific non-covalent interactions" ], "answer": 2, "explanation": "Many pathogens are prevented from entering tissues. Tightly joined cells, dryness and antimicrobial secretions create a physical and chemical barrier." }, { "id": "immunity-phagocytosis-outcome", "chapter": "Immunity", "difficulty": "Foundation", "stem": "After a phagocyte recognizes and surrounds a bacterium, which observation is most likely?", "options": [ "Local blood flow and capillary permeability increase", "A clone of effector and memory cells develops", "The antibody binds that antigen selectively", "The bacterium becomes enclosed and digested" ], "answer": 3, "explanation": "The bacterium becomes enclosed and digested. A phagosome fuses with enzyme-containing lysosomes." }, { "id": "immunity-phagocytosis-cause", "chapter": "Immunity", "difficulty": "Foundation", "stem": "A learner records that the bacterium becomes enclosed and digested. Which preceding event best accounts for it?", "options": [ "A phagocyte recognizes and surrounds a bacterium", "An antibody variable region is complementary to an antigenic epitope", "Damaged tissue releases inflammatory mediators", "An antigen activates a matching naive lymphocyte" ], "answer": 0, "explanation": "The bacterium becomes enclosed and digested. A phagosome fuses with enzyme-containing lysosomes." }, { "id": "immunity-phagocytosis-mechanism", "chapter": "Immunity", "difficulty": "Foundation", "stem": "After a phagocyte recognizes and surrounds a bacterium, which explanation best links the change to its outcome?", "options": [ "Vasodilation and endothelial changes deliver plasma proteins and leukocytes", "A phagosome fuses with enzyme-containing lysosomes", "Specific receptor recognition triggers proliferation and differentiation", "Shape and charge complementarity permit specific non-covalent interactions" ], "answer": 1, "explanation": "The bacterium becomes enclosed and digested. A phagosome fuses with enzyme-containing lysosomes." }, { "id": "immunity-phagocytosis-integrated", "chapter": "Immunity", "difficulty": "Foundation", "stem": "Which paired outcome and explanation best follows from this condition: a phagocyte recognizes and surrounds a bacterium?", "options": [ "The antibody binds that antigen selectively — Shape and charge complementarity permit specific non-covalent interactions", "Local blood flow and capillary permeability increase — Vasodilation and endothelial changes deliver plasma proteins and leukocytes", "The bacterium becomes enclosed and digested — A phagosome fuses with enzyme-containing lysosomes", "A clone of effector and memory cells develops — Specific receptor recognition triggers proliferation and differentiation" ], "answer": 2, "explanation": "The bacterium becomes enclosed and digested. A phagosome fuses with enzyme-containing lysosomes." }, { "id": "immunity-inflammation-outcome", "chapter": "Immunity", "difficulty": "Foundation", "stem": "A student models this change: Damaged tissue releases inflammatory mediators. What should the model predict first?", "options": [ "The antibody binds that antigen selectively", "A clone of effector and memory cells develops", "Immunological memory forms before natural exposure", "Local blood flow and capillary permeability increase" ], "answer": 3, "explanation": "Local blood flow and capillary permeability increase. Vasodilation and endothelial changes deliver plasma proteins and leukocytes." }, { "id": "immunity-inflammation-cause", "chapter": "Immunity", "difficulty": "Foundation", "stem": "What is the most likely cause when local blood flow and capillary permeability increase?", "options": [ "Damaged tissue releases inflammatory mediators", "An antigen activates a matching naive lymphocyte", "A person receives a safe preparation containing pathogen antigens", "An antibody variable region is complementary to an antigenic epitope" ], "answer": 0, "explanation": "Local blood flow and capillary permeability increase. Vasodilation and endothelial changes deliver plasma proteins and leukocytes." }, { "id": "immunity-inflammation-mechanism", "chapter": "Immunity", "difficulty": "Foundation", "stem": "After damaged tissue releases inflammatory mediators, which explanation best links the change to its outcome?", "options": [ "Shape and charge complementarity permit specific non-covalent interactions", "Vasodilation and endothelial changes deliver plasma proteins and leukocytes", "Specific receptor recognition triggers proliferation and differentiation", "A primary adaptive response generates long-lived antigen-specific lymphocytes" ], "answer": 1, "explanation": "Local blood flow and capillary permeability increase. Vasodilation and endothelial changes deliver plasma proteins and leukocytes." }, { "id": "immunity-inflammation-integrated", "chapter": "Immunity", "difficulty": "Foundation", "stem": "Which paired outcome and explanation best follows from this condition: damaged tissue releases inflammatory mediators?", "options": [ "The antibody binds that antigen selectively — Shape and charge complementarity permit specific non-covalent interactions", "A clone of effector and memory cells develops — Specific receptor recognition triggers proliferation and differentiation", "Local blood flow and capillary permeability increase — Vasodilation and endothelial changes deliver plasma proteins and leukocytes", "Immunological memory forms before natural exposure — A primary adaptive response generates long-lived antigen-specific lymphocytes" ], "answer": 2, "explanation": "Local blood flow and capillary permeability increase. Vasodilation and endothelial changes deliver plasma proteins and leukocytes." }, { "id": "immunity-antibody-specific-outcome", "chapter": "Immunity", "difficulty": "Foundation", "stem": "Which immediate result is most consistent with this condition: An antibody variable region is complementary to an antigenic epitope?", "options": [ "A clone of effector and memory cells develops", "Immunological memory forms before natural exposure", "Opsonization, inflammation and membrane damage are promoted", "The antibody binds that antigen selectively" ], "answer": 3, "explanation": "The antibody binds that antigen selectively. Shape and charge complementarity permit specific non-covalent interactions." }, { "id": "immunity-antibody-specific-cause", "chapter": "Immunity", "difficulty": "Foundation", "stem": "Which condition would most specifically produce this result: the antibody binds that antigen selectively?", "options": [ "An antibody variable region is complementary to an antigenic epitope", "An antigen activates a matching naive lymphocyte", "A person receives a safe preparation containing pathogen antigens", "Complement proteins become activated on a microbial surface" ], "answer": 0, "explanation": "The antibody binds that antigen selectively. Shape and charge complementarity permit specific non-covalent interactions." }, { "id": "immunity-antibody-specific-mechanism", "chapter": "Immunity", "difficulty": "Foundation", "stem": "After an antibody variable region is complementary to an antigenic epitope, which explanation best links the change to its outcome?", "options": [ "Specific receptor recognition triggers proliferation and differentiation", "Shape and charge complementarity permit specific non-covalent interactions", "A primary adaptive response generates long-lived antigen-specific lymphocytes", "A proteolytic cascade deposits binding fragments and can assemble membrane-attack complexes" ], "answer": 1, "explanation": "The antibody binds that antigen selectively. Shape and charge complementarity permit specific non-covalent interactions." }, { "id": "immunity-antibody-specific-integrated", "chapter": "Immunity", "difficulty": "Foundation", "stem": "Which paired outcome and explanation best follows from this condition: an antibody variable region is complementary to an antigenic epitope?", "options": [ "A clone of effector and memory cells develops — Specific receptor recognition triggers proliferation and differentiation", "Immunological memory forms before natural exposure — A primary adaptive response generates long-lived antigen-specific lymphocytes", "The antibody binds that antigen selectively — Shape and charge complementarity permit specific non-covalent interactions", "Opsonization, inflammation and membrane damage are promoted — A proteolytic cascade deposits binding fragments and can assemble membrane-attack complexes" ], "answer": 2, "explanation": "The antibody binds that antigen selectively. Shape and charge complementarity permit specific non-covalent interactions." }, { "id": "immunity-clonal-selection-outcome", "chapter": "Immunity", "difficulty": "Foundation", "stem": "An antigen activates a matching naive lymphocyte. Which outcome follows most directly?", "options": [ "Rapid phagocytosis and microbial killing increase", "Immunological memory forms before natural exposure", "Opsonization, inflammation and membrane damage are promoted", "A clone of effector and memory cells develops" ], "answer": 3, "explanation": "A clone of effector and memory cells develops. Specific receptor recognition triggers proliferation and differentiation." }, { "id": "immunity-clonal-selection-cause", "chapter": "Immunity", "difficulty": "Foundation", "stem": "Which change most directly explains this observation: a clone of effector and memory cells develops?", "options": [ "An antigen activates a matching naive lymphocyte", "A person receives a safe preparation containing pathogen antigens", "Complement proteins become activated on a microbial surface", "Chemotactic signals attract neutrophils to an acute bacterial infection" ], "answer": 0, "explanation": "A clone of effector and memory cells develops. Specific receptor recognition triggers proliferation and differentiation." }, { "id": "immunity-clonal-selection-mechanism", "chapter": "Immunity", "difficulty": "Foundation", "stem": "After an antigen activates a matching naive lymphocyte, which explanation best links the change to its outcome?", "options": [ "A primary adaptive response generates long-lived antigen-specific lymphocytes", "Specific receptor recognition triggers proliferation and differentiation", "A proteolytic cascade deposits binding fragments and can assemble membrane-attack complexes", "Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules" ], "answer": 1, "explanation": "A clone of effector and memory cells develops. Specific receptor recognition triggers proliferation and differentiation." }, { "id": "immunity-clonal-selection-integrated", "chapter": "Immunity", "difficulty": "Foundation", "stem": "Which paired outcome and explanation best follows from this condition: an antigen activates a matching naive lymphocyte?", "options": [ "Immunological memory forms before natural exposure — A primary adaptive response generates long-lived antigen-specific lymphocytes", "Opsonization, inflammation and membrane damage are promoted — A proteolytic cascade deposits binding fragments and can assemble membrane-attack complexes", "A clone of effector and memory cells develops — Specific receptor recognition triggers proliferation and differentiation", "Rapid phagocytosis and microbial killing increase — Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules" ], "answer": 2, "explanation": "A clone of effector and memory cells develops. Specific receptor recognition triggers proliferation and differentiation." }, { "id": "immunity-vaccination-outcome", "chapter": "Immunity", "difficulty": "Foundation", "stem": "After a person receives a safe preparation containing pathogen antigens, which observation is most likely?", "options": [ "Opsonization, inflammation and membrane damage are promoted", "A matching CD4 helper T cell can become activated", "Rapid phagocytosis and microbial killing increase", "Immunological memory forms before natural exposure" ], "answer": 3, "explanation": "Immunological memory forms before natural exposure. A primary adaptive response generates long-lived antigen-specific lymphocytes." }, { "id": "immunity-vaccination-cause", "chapter": "Immunity", "difficulty": "Foundation", "stem": "A learner records that immunological memory forms before natural exposure. Which preceding event best accounts for it?", "options": [ "A person receives a safe preparation containing pathogen antigens", "Chemotactic signals attract neutrophils to an acute bacterial infection", "Complement proteins become activated on a microbial surface", "An antigen-presenting cell displays an extracellular peptide on MHC class II" ], "answer": 0, "explanation": "Immunological memory forms before natural exposure. A primary adaptive response generates long-lived antigen-specific lymphocytes." }, { "id": "immunity-vaccination-mechanism", "chapter": "Immunity", "difficulty": "Foundation", "stem": "After a person receives a safe preparation containing pathogen antigens, which explanation best links the change to its outcome?", "options": [ "A proteolytic cascade deposits binding fragments and can assemble membrane-attack complexes", "A primary adaptive response generates long-lived antigen-specific lymphocytes", "The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals", "Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules" ], "answer": 1, "explanation": "Immunological memory forms before natural exposure. A primary adaptive response generates long-lived antigen-specific lymphocytes." }, { "id": "immunity-vaccination-integrated", "chapter": "Immunity", "difficulty": "Foundation", "stem": "Which paired outcome and explanation best follows from this condition: a person receives a safe preparation containing pathogen antigens?", "options": [ "Rapid phagocytosis and microbial killing increase — Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules", "Opsonization, inflammation and membrane damage are promoted — A proteolytic cascade deposits binding fragments and can assemble membrane-attack complexes", "Immunological memory forms before natural exposure — A primary adaptive response generates long-lived antigen-specific lymphocytes", "A matching CD4 helper T cell can become activated — The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals" ], "answer": 2, "explanation": "Immunological memory forms before natural exposure. A primary adaptive response generates long-lived antigen-specific lymphocytes." }, { "id": "immunity-complement-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "A student models this change: Complement proteins become activated on a microbial surface. What should the model predict first?", "options": [ "Rapid phagocytosis and microbial killing increase", "A matching CD4 helper T cell can become activated", "B-cell and cytotoxic-T-cell responses are strengthened", "Opsonization, inflammation and membrane damage are promoted" ], "answer": 3, "explanation": "Opsonization, inflammation and membrane damage are promoted. A proteolytic cascade deposits binding fragments and can assemble membrane-attack complexes." }, { "id": "immunity-complement-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "What is the most likely cause when opsonization, inflammation and membrane damage are promoted?", "options": [ "Complement proteins become activated on a microbial surface", "An antigen-presenting cell displays an extracellular peptide on MHC class II", "Activated helper T cells release appropriate cytokines", "Chemotactic signals attract neutrophils to an acute bacterial infection" ], "answer": 0, "explanation": "Opsonization, inflammation and membrane damage are promoted. A proteolytic cascade deposits binding fragments and can assemble membrane-attack complexes." }, { "id": "immunity-complement-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After complement proteins become activated on a microbial surface, which explanation best links the change to its outcome?", "options": [ "Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules", "A proteolytic cascade deposits binding fragments and can assemble membrane-attack complexes", "The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals", "Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes" ], "answer": 1, "explanation": "Opsonization, inflammation and membrane damage are promoted. A proteolytic cascade deposits binding fragments and can assemble membrane-attack complexes." }, { "id": "immunity-neutrophil-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which immediate result is most consistent with this condition: Chemotactic signals attract neutrophils to an acute bacterial infection?", "options": [ "A matching CD4 helper T cell can become activated", "B-cell and cytotoxic-T-cell responses are strengthened", "Rapid phagocytosis and microbial killing increase", "Large quantities of one antibody specificity are secreted" ], "answer": 2, "explanation": "Rapid phagocytosis and microbial killing increase. Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules." }, { "id": "immunity-neutrophil-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which condition would most specifically produce this result: rapid phagocytosis and microbial killing increase?", "options": [ "An activated B cell differentiates into a plasma cell", "An antigen-presenting cell displays an extracellular peptide on MHC class II", "Activated helper T cells release appropriate cytokines", "Chemotactic signals attract neutrophils to an acute bacterial infection" ], "answer": 3, "explanation": "Rapid phagocytosis and microbial killing increase. Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules." }, { "id": "immunity-neutrophil-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After chemotactic signals attract neutrophils to an acute bacterial infection, which explanation best links the change to its outcome?", "options": [ "Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules", "The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals", "Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes", "Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export" ], "answer": 0, "explanation": "Rapid phagocytosis and microbial killing increase. Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules." }, { "id": "immunity-neutrophil-integrated", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which paired outcome and explanation best follows from this condition: chemotactic signals attract neutrophils to an acute bacterial infection?", "options": [ "A matching CD4 helper T cell can become activated — The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals", "Rapid phagocytosis and microbial killing increase — Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules", "B-cell and cytotoxic-T-cell responses are strengthened — Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes", "Large quantities of one antibody specificity are secreted — Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export" ], "answer": 1, "explanation": "Rapid phagocytosis and microbial killing increase. Neutrophils migrate through vessel walls and deploy granule enzymes and reactive molecules." }, { "id": "immunity-mhc-two-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "An antigen-presenting cell displays an extracellular peptide on MHC class II. Which outcome follows most directly?", "options": [ "Large quantities of one antibody specificity are secreted", "B-cell and cytotoxic-T-cell responses are strengthened", "A matching CD4 helper T cell can become activated", "The infected cell is induced to die" ], "answer": 2, "explanation": "A matching CD4 helper T cell can become activated. The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals." }, { "id": "immunity-mhc-two-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which change most directly explains this observation: a matching CD4 helper T cell can become activated?", "options": [ "Activated helper T cells release appropriate cytokines", "A cytotoxic T cell recognizes viral peptide on MHC class I", "An activated B cell differentiates into a plasma cell", "An antigen-presenting cell displays an extracellular peptide on MHC class II" ], "answer": 3, "explanation": "A matching CD4 helper T cell can become activated. The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals." }, { "id": "immunity-mhc-two-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After an antigen-presenting cell displays an extracellular peptide on MHC class II, which explanation best links the change to its outcome?", "options": [ "The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals", "Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export", "Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes", "Perforin and granzymes or death-receptor signals activate apoptosis" ], "answer": 0, "explanation": "A matching CD4 helper T cell can become activated. The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals." }, { "id": "immunity-mhc-two-integrated", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which paired outcome and explanation best follows from this condition: an antigen-presenting cell displays an extracellular peptide on MHC class II?", "options": [ "B-cell and cytotoxic-T-cell responses are strengthened — Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes", "A matching CD4 helper T cell can become activated — The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals", "The infected cell is induced to die — Perforin and granzymes or death-receptor signals activate apoptosis", "Large quantities of one antibody specificity are secreted — Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export" ], "answer": 1, "explanation": "A matching CD4 helper T cell can become activated. The T-cell receptor recognizes the peptide-MHC complex with costimulatory signals." }, { "id": "immunity-helper-t-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "After activated helper T cells release appropriate cytokines, which observation is most likely?", "options": [ "Large quantities of one antibody specificity are secreted", "The infected cell is induced to die", "B-cell and cytotoxic-T-cell responses are strengthened", "A faster and larger secondary response occurs" ], "answer": 2, "explanation": "B-cell and cytotoxic-T-cell responses are strengthened. Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes." }, { "id": "immunity-helper-t-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "A learner records that b-cell and cytotoxic-T-cell responses are strengthened. Which preceding event best accounts for it?", "options": [ "An activated B cell differentiates into a plasma cell", "A cytotoxic T cell recognizes viral peptide on MHC class I", "A previously encountered antigen enters the body again", "Activated helper T cells release appropriate cytokines" ], "answer": 3, "explanation": "B-cell and cytotoxic-T-cell responses are strengthened. Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes." }, { "id": "immunity-helper-t-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After activated helper T cells release appropriate cytokines, which explanation best links the change to its outcome?", "options": [ "Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes", "Perforin and granzymes or death-receptor signals activate apoptosis", "Memory lymphocytes are more numerous and activate more readily than naive cells", "Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export" ], "answer": 0, "explanation": "B-cell and cytotoxic-T-cell responses are strengthened. Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes." }, { "id": "immunity-helper-t-integrated", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which paired outcome and explanation best follows from this condition: activated helper T cells release appropriate cytokines?", "options": [ "Large quantities of one antibody specificity are secreted — Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export", "B-cell and cytotoxic-T-cell responses are strengthened — Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes", "The infected cell is induced to die — Perforin and granzymes or death-receptor signals activate apoptosis", "A faster and larger secondary response occurs — Memory lymphocytes are more numerous and activate more readily than naive cells" ], "answer": 1, "explanation": "B-cell and cytotoxic-T-cell responses are strengthened. Cytokine signalling promotes clonal expansion and differentiation of adaptive lymphocytes." }, { "id": "immunity-plasma-cell-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "A student models this change: An activated B cell differentiates into a plasma cell. What should the model predict first?", "options": [ "The infected cell is induced to die", "A faster and larger secondary response occurs", "Large quantities of one antibody specificity are secreted", "Protection appears rapidly but is temporary" ], "answer": 2, "explanation": "Large quantities of one antibody specificity are secreted. Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export." }, { "id": "immunity-plasma-cell-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "What is the most likely cause when large quantities of one antibody specificity are secreted?", "options": [ "A cytotoxic T cell recognizes viral peptide on MHC class I", "A previously encountered antigen enters the body again", "Preformed antibodies are transferred to a non-immune person", "An activated B cell differentiates into a plasma cell" ], "answer": 3, "explanation": "Large quantities of one antibody specificity are secreted. Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export." }, { "id": "immunity-plasma-cell-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After an activated B cell differentiates into a plasma cell, which explanation best links the change to its outcome?", "options": [ "Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export", "Perforin and granzymes or death-receptor signals activate apoptosis", "Memory lymphocytes are more numerous and activate more readily than naive cells", "Antibodies act immediately but no recipient memory-cell clone is generated" ], "answer": 0, "explanation": "Large quantities of one antibody specificity are secreted. Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export." }, { "id": "immunity-plasma-cell-integrated", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which paired outcome and explanation best follows from this condition: an activated B cell differentiates into a plasma cell?", "options": [ "The infected cell is induced to die — Perforin and granzymes or death-receptor signals activate apoptosis", "Large quantities of one antibody specificity are secreted — Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export", "A faster and larger secondary response occurs — Memory lymphocytes are more numerous and activate more readily than naive cells", "Protection appears rapidly but is temporary — Antibodies act immediately but no recipient memory-cell clone is generated" ], "answer": 1, "explanation": "Large quantities of one antibody specificity are secreted. Expanded rough ER and Golgi support rapid immunoglobulin synthesis and export." }, { "id": "immunity-cytotoxic-t-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which immediate result is most consistent with this condition: A cytotoxic T cell recognizes viral peptide on MHC class I?", "options": [ "A faster and larger secondary response occurs", "Protection appears rapidly but is temporary", "The infected cell is induced to die", "Protection develops more slowly but can persist" ], "answer": 2, "explanation": "The infected cell is induced to die. Perforin and granzymes or death-receptor signals activate apoptosis." }, { "id": "immunity-cytotoxic-t-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which condition would most specifically produce this result: the infected cell is induced to die?", "options": [ "A person mounts their own adaptive response to an antigen", "A previously encountered antigen enters the body again", "Preformed antibodies are transferred to a non-immune person", "A cytotoxic T cell recognizes viral peptide on MHC class I" ], "answer": 3, "explanation": "The infected cell is induced to die. Perforin and granzymes or death-receptor signals activate apoptosis." }, { "id": "immunity-cytotoxic-t-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After a cytotoxic T cell recognizes viral peptide on MHC class I, which explanation best links the change to its outcome?", "options": [ "Perforin and granzymes or death-receptor signals activate apoptosis", "Memory lymphocytes are more numerous and activate more readily than naive cells", "Antibodies act immediately but no recipient memory-cell clone is generated", "Clonal selection produces effector cells and long-lived memory cells" ], "answer": 0, "explanation": "The infected cell is induced to die. Perforin and granzymes or death-receptor signals activate apoptosis." }, { "id": "immunity-cytotoxic-t-integrated", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which paired outcome and explanation best follows from this condition: a cytotoxic T cell recognizes viral peptide on MHC class I?", "options": [ "A faster and larger secondary response occurs — Memory lymphocytes are more numerous and activate more readily than naive cells", "The infected cell is induced to die — Perforin and granzymes or death-receptor signals activate apoptosis", "Protection appears rapidly but is temporary — Antibodies act immediately but no recipient memory-cell clone is generated", "Protection develops more slowly but can persist — Clonal selection produces effector cells and long-lived memory cells" ], "answer": 1, "explanation": "The infected cell is induced to die. Perforin and granzymes or death-receptor signals activate apoptosis." }, { "id": "immunity-memory-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "A previously encountered antigen enters the body again. Which outcome follows most directly?", "options": [ "Protection develops more slowly but can persist", "Protection appears rapidly but is temporary", "A faster and larger secondary response occurs", "The cells clump together" ], "answer": 2, "explanation": "A faster and larger secondary response occurs. Memory lymphocytes are more numerous and activate more readily than naive cells." }, { "id": "immunity-memory-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which change most directly explains this observation: a faster and larger secondary response occurs?", "options": [ "Preformed antibodies are transferred to a non-immune person", "Antibodies bind repeated antigens on several microbial cells", "A person mounts their own adaptive response to an antigen", "A previously encountered antigen enters the body again" ], "answer": 3, "explanation": "A faster and larger secondary response occurs. Memory lymphocytes are more numerous and activate more readily than naive cells." }, { "id": "immunity-memory-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After a previously encountered antigen enters the body again, which explanation best links the change to its outcome?", "options": [ "Memory lymphocytes are more numerous and activate more readily than naive cells", "Clonal selection produces effector cells and long-lived memory cells", "Antibodies act immediately but no recipient memory-cell clone is generated", "Multiple antigen-binding sites cross-link particles and improve clearance" ], "answer": 0, "explanation": "A faster and larger secondary response occurs. Memory lymphocytes are more numerous and activate more readily than naive cells." }, { "id": "immunity-passive-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "After preformed antibodies are transferred to a non-immune person, which observation is most likely?", "options": [ "Protection develops more slowly but can persist", "Protection appears rapidly but is temporary", "The cells clump together", "The toxin cannot attach effectively to target cells" ], "answer": 1, "explanation": "Protection appears rapidly but is temporary. Antibodies act immediately but no recipient memory-cell clone is generated." }, { "id": "immunity-passive-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "A learner records that protection appears rapidly but is temporary. Which preceding event best accounts for it?", "options": [ "A person mounts their own adaptive response to an antigen", "Antibodies bind repeated antigens on several microbial cells", "Preformed antibodies are transferred to a non-immune person", "Antibodies bind a toxin's receptor-binding region" ], "answer": 2, "explanation": "Protection appears rapidly but is temporary. Antibodies act immediately but no recipient memory-cell clone is generated." }, { "id": "immunity-passive-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After preformed antibodies are transferred to a non-immune person, which explanation best links the change to its outcome?", "options": [ "Clonal selection produces effector cells and long-lived memory cells", "Multiple antigen-binding sites cross-link particles and improve clearance", "Steric blocking prevents the molecular interaction required for toxicity", "Antibodies act immediately but no recipient memory-cell clone is generated" ], "answer": 3, "explanation": "Protection appears rapidly but is temporary. Antibodies act immediately but no recipient memory-cell clone is generated." }, { "id": "immunity-passive-integrated", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which paired outcome and explanation best follows from this condition: preformed antibodies are transferred to a non-immune person?", "options": [ "Protection appears rapidly but is temporary — Antibodies act immediately but no recipient memory-cell clone is generated", "Protection develops more slowly but can persist — Clonal selection produces effector cells and long-lived memory cells", "The cells clump together — Multiple antigen-binding sites cross-link particles and improve clearance", "The toxin cannot attach effectively to target cells — Steric blocking prevents the molecular interaction required for toxicity" ], "answer": 0, "explanation": "Protection appears rapidly but is temporary. Antibodies act immediately but no recipient memory-cell clone is generated." }, { "id": "immunity-active-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "A student models this change: A person mounts their own adaptive response to an antigen. What should the model predict first?", "options": [ "The cells clump together", "Protection develops more slowly but can persist", "The toxin cannot attach effectively to target cells", "Body temperature rises and some immune processes accelerate" ], "answer": 1, "explanation": "Protection develops more slowly but can persist. Clonal selection produces effector cells and long-lived memory cells." }, { "id": "immunity-active-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "What is the most likely cause when protection develops more slowly but can persist?", "options": [ "Antibodies bind repeated antigens on several microbial cells", "Antibodies bind a toxin's receptor-binding region", "A person mounts their own adaptive response to an antigen", "Pyrogens raise the hypothalamic set point during infection" ], "answer": 2, "explanation": "Protection develops more slowly but can persist. Clonal selection produces effector cells and long-lived memory cells." }, { "id": "immunity-active-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After a person mounts their own adaptive response to an antigen, which explanation best links the change to its outcome?", "options": [ "Heat-conserving and heat-producing responses continue until the new set point is reached", "Multiple antigen-binding sites cross-link particles and improve clearance", "Steric blocking prevents the molecular interaction required for toxicity", "Clonal selection produces effector cells and long-lived memory cells" ], "answer": 3, "explanation": "Protection develops more slowly but can persist. Clonal selection produces effector cells and long-lived memory cells." }, { "id": "immunity-active-integrated", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which paired outcome and explanation best follows from this condition: a person mounts their own adaptive response to an antigen?", "options": [ "Protection develops more slowly but can persist — Clonal selection produces effector cells and long-lived memory cells", "The cells clump together — Multiple antigen-binding sites cross-link particles and improve clearance", "The toxin cannot attach effectively to target cells — Steric blocking prevents the molecular interaction required for toxicity", "Body temperature rises and some immune processes accelerate — Heat-conserving and heat-producing responses continue until the new set point is reached" ], "answer": 0, "explanation": "Protection develops more slowly but can persist. Clonal selection produces effector cells and long-lived memory cells." }, { "id": "immunity-agglutination-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which immediate result is most consistent with this condition: Antibodies bind repeated antigens on several microbial cells?", "options": [ "The toxin cannot attach effectively to target cells", "The cells clump together", "Opportunistic infections become increasingly likely", "Body temperature rises and some immune processes accelerate" ], "answer": 1, "explanation": "The cells clump together. Multiple antigen-binding sites cross-link particles and improve clearance." }, { "id": "immunity-agglutination-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which condition would most specifically produce this result: the cells clump together?", "options": [ "Pyrogens raise the hypothalamic set point during infection", "Antibodies bind a toxin's receptor-binding region", "Antibodies bind repeated antigens on several microbial cells", "HIV depletes CD4 helper T cells over time" ], "answer": 2, "explanation": "The cells clump together. Multiple antigen-binding sites cross-link particles and improve clearance." }, { "id": "immunity-agglutination-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After antibodies bind repeated antigens on several microbial cells, which explanation best links the change to its outcome?", "options": [ "Steric blocking prevents the molecular interaction required for toxicity", "Loss of helper signals undermines both cell-mediated and antibody responses", "Heat-conserving and heat-producing responses continue until the new set point is reached", "Multiple antigen-binding sites cross-link particles and improve clearance" ], "answer": 3, "explanation": "The cells clump together. Multiple antigen-binding sites cross-link particles and improve clearance." }, { "id": "immunity-agglutination-integrated", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which paired outcome and explanation best follows from this condition: antibodies bind repeated antigens on several microbial cells?", "options": [ "The cells clump together — Multiple antigen-binding sites cross-link particles and improve clearance", "Body temperature rises and some immune processes accelerate — Heat-conserving and heat-producing responses continue until the new set point is reached", "The toxin cannot attach effectively to target cells — Steric blocking prevents the molecular interaction required for toxicity", "Opportunistic infections become increasingly likely — Loss of helper signals undermines both cell-mediated and antibody responses" ], "answer": 0, "explanation": "The cells clump together. Multiple antigen-binding sites cross-link particles and improve clearance." }, { "id": "immunity-neutralization-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "Antibodies bind a toxin's receptor-binding region. Which outcome follows most directly?", "options": [ "Body temperature rises and some immune processes accelerate", "The toxin cannot attach effectively to target cells", "Opportunistic infections become increasingly likely", "Immune attack damages the body's own tissues" ], "answer": 1, "explanation": "The toxin cannot attach effectively to target cells. Steric blocking prevents the molecular interaction required for toxicity." }, { "id": "immunity-neutralization-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which change most directly explains this observation: the toxin cannot attach effectively to target cells?", "options": [ "Pyrogens raise the hypothalamic set point during infection", "HIV depletes CD4 helper T cells over time", "Antibodies bind a toxin's receptor-binding region", "Self-reactive lymphocytes escape tolerance and become activated" ], "answer": 2, "explanation": "The toxin cannot attach effectively to target cells. Steric blocking prevents the molecular interaction required for toxicity." }, { "id": "immunity-neutralization-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After antibodies bind a toxin's receptor-binding region, which explanation best links the change to its outcome?", "options": [ "Heat-conserving and heat-producing responses continue until the new set point is reached", "Loss of helper signals undermines both cell-mediated and antibody responses", "Adaptive receptors recognize self antigens as targets", "Steric blocking prevents the molecular interaction required for toxicity" ], "answer": 3, "explanation": "The toxin cannot attach effectively to target cells. Steric blocking prevents the molecular interaction required for toxicity." }, { "id": "immunity-neutralization-integrated", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which paired outcome and explanation best follows from this condition: antibodies bind a toxin's receptor-binding region?", "options": [ "The toxin cannot attach effectively to target cells — Steric blocking prevents the molecular interaction required for toxicity", "Opportunistic infections become increasingly likely — Loss of helper signals undermines both cell-mediated and antibody responses", "Immune attack damages the body's own tissues — Adaptive receptors recognize self antigens as targets", "Body temperature rises and some immune processes accelerate — Heat-conserving and heat-producing responses continue until the new set point is reached" ], "answer": 0, "explanation": "The toxin cannot attach effectively to target cells. Steric blocking prevents the molecular interaction required for toxicity." }, { "id": "immunity-fever-outcome", "chapter": "Immunity", "difficulty": "Standard", "stem": "After pyrogens raise the hypothalamic set point during infection, which observation is most likely?", "options": [ "Opportunistic infections become increasingly likely", "Body temperature rises and some immune processes accelerate", "Immune attack damages the body's own tissues", "Histamine and other mediators are rapidly released" ], "answer": 1, "explanation": "Body temperature rises and some immune processes accelerate. Heat-conserving and heat-producing responses continue until the new set point is reached." }, { "id": "immunity-fever-cause", "chapter": "Immunity", "difficulty": "Standard", "stem": "A learner records that body temperature rises and some immune processes accelerate. Which preceding event best accounts for it?", "options": [ "HIV depletes CD4 helper T cells over time", "Self-reactive lymphocytes escape tolerance and become activated", "Pyrogens raise the hypothalamic set point during infection", "An allergen cross-links IgE on sensitized mast cells" ], "answer": 2, "explanation": "Body temperature rises and some immune processes accelerate. Heat-conserving and heat-producing responses continue until the new set point is reached." }, { "id": "immunity-fever-mechanism", "chapter": "Immunity", "difficulty": "Standard", "stem": "After pyrogens raise the hypothalamic set point during infection, which explanation best links the change to its outcome?", "options": [ "Loss of helper signals undermines both cell-mediated and antibody responses", "Adaptive receptors recognize self antigens as targets", "Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects", "Heat-conserving and heat-producing responses continue until the new set point is reached" ], "answer": 3, "explanation": "Body temperature rises and some immune processes accelerate. Heat-conserving and heat-producing responses continue until the new set point is reached." }, { "id": "immunity-fever-integrated", "chapter": "Immunity", "difficulty": "Standard", "stem": "Which paired outcome and explanation best follows from this condition: pyrogens raise the hypothalamic set point during infection?", "options": [ "Body temperature rises and some immune processes accelerate — Heat-conserving and heat-producing responses continue until the new set point is reached", "Opportunistic infections become increasingly likely — Loss of helper signals undermines both cell-mediated and antibody responses", "Immune attack damages the body's own tissues — Adaptive receptors recognize self antigens as targets", "Histamine and other mediators are rapidly released — Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects" ], "answer": 0, "explanation": "Body temperature rises and some immune processes accelerate. Heat-conserving and heat-producing responses continue until the new set point is reached." }, { "id": "immunity-hiv-outcome", "chapter": "Immunity", "difficulty": "Challenge", "stem": "A student models this change: HIV depletes CD4 helper T cells over time. What should the model predict first?", "options": [ "Immune attack damages the body's own tissues", "Opportunistic infections become increasingly likely", "Histamine and other mediators are rapidly released", "Immune rejection can damage the graft" ], "answer": 1, "explanation": "Opportunistic infections become increasingly likely. Loss of helper signals undermines both cell-mediated and antibody responses." }, { "id": "immunity-hiv-cause", "chapter": "Immunity", "difficulty": "Challenge", "stem": "What is the most likely cause when opportunistic infections become increasingly likely?", "options": [ "Self-reactive lymphocytes escape tolerance and become activated", "An allergen cross-links IgE on sensitized mast cells", "HIV depletes CD4 helper T cells over time", "Recipient T cells recognize non-self MHC on a transplanted organ" ], "answer": 2, "explanation": "Opportunistic infections become increasingly likely. Loss of helper signals undermines both cell-mediated and antibody responses." }, { "id": "immunity-hiv-mechanism", "chapter": "Immunity", "difficulty": "Challenge", "stem": "After HIV depletes CD4 helper T cells over time, which explanation best links the change to its outcome?", "options": [ "Alloreactive lymphocytes activate cytotoxic and inflammatory pathways", "Adaptive receptors recognize self antigens as targets", "Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects", "Loss of helper signals undermines both cell-mediated and antibody responses" ], "answer": 3, "explanation": "Opportunistic infections become increasingly likely. Loss of helper signals undermines both cell-mediated and antibody responses." }, { "id": "immunity-autoimmunity-outcome", "chapter": "Immunity", "difficulty": "Challenge", "stem": "Which immediate result is most consistent with this condition: Self-reactive lymphocytes escape tolerance and become activated?", "options": [ "Immune attack damages the body's own tissues", "Immune rejection can damage the graft", "Established antibodies and memory cells become less effective", "Histamine and other mediators are rapidly released" ], "answer": 0, "explanation": "Immune attack damages the body's own tissues. Adaptive receptors recognize self antigens as targets." }, { "id": "immunity-autoimmunity-cause", "chapter": "Immunity", "difficulty": "Challenge", "stem": "Which condition would most specifically produce this result: immune attack damages the body's own tissues?", "options": [ "An allergen cross-links IgE on sensitized mast cells", "Self-reactive lymphocytes escape tolerance and become activated", "Recipient T cells recognize non-self MHC on a transplanted organ", "A pathogen repeatedly changes exposed antigenic structures" ], "answer": 1, "explanation": "Immune attack damages the body's own tissues. Adaptive receptors recognize self antigens as targets." }, { "id": "immunity-autoimmunity-mechanism", "chapter": "Immunity", "difficulty": "Challenge", "stem": "After self-reactive lymphocytes escape tolerance and become activated, which explanation best links the change to its outcome?", "options": [ "Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects", "Alloreactive lymphocytes activate cytotoxic and inflammatory pathways", "Adaptive receptors recognize self antigens as targets", "New epitopes are poorly recognized by clones selected against earlier variants" ], "answer": 2, "explanation": "Immune attack damages the body's own tissues. Adaptive receptors recognize self antigens as targets." }, { "id": "immunity-autoimmunity-integrated", "chapter": "Immunity", "difficulty": "Challenge", "stem": "Which paired outcome and explanation best follows from this condition: self-reactive lymphocytes escape tolerance and become activated?", "options": [ "Histamine and other mediators are rapidly released — Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects", "Immune rejection can damage the graft — Alloreactive lymphocytes activate cytotoxic and inflammatory pathways", "Established antibodies and memory cells become less effective — New epitopes are poorly recognized by clones selected against earlier variants", "Immune attack damages the body's own tissues — Adaptive receptors recognize self antigens as targets" ], "answer": 3, "explanation": "Immune attack damages the body's own tissues. Adaptive receptors recognize self antigens as targets." }, { "id": "immunity-allergy-outcome", "chapter": "Immunity", "difficulty": "Challenge", "stem": "An allergen cross-links IgE on sensitized mast cells. Which outcome follows most directly?", "options": [ "Histamine and other mediators are rapidly released", "Immune rejection can damage the graft", "Established antibodies and memory cells become less effective", "Antibody concentration and average affinity rise rapidly" ], "answer": 0, "explanation": "Histamine and other mediators are rapidly released. Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects." }, { "id": "immunity-allergy-cause", "chapter": "Immunity", "difficulty": "Challenge", "stem": "Which change most directly explains this observation: histamine and other mediators are rapidly released?", "options": [ "Recipient T cells recognize non-self MHC on a transplanted organ", "An allergen cross-links IgE on sensitized mast cells", "A pathogen repeatedly changes exposed antigenic structures", "A vaccine booster re-exposes a person to the same antigen" ], "answer": 1, "explanation": "Histamine and other mediators are rapidly released. Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects." }, { "id": "immunity-allergy-mechanism", "chapter": "Immunity", "difficulty": "Challenge", "stem": "After an allergen cross-links IgE on sensitized mast cells, which explanation best links the change to its outcome?", "options": [ "Alloreactive lymphocytes activate cytotoxic and inflammatory pathways", "New epitopes are poorly recognized by clones selected against earlier variants", "Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects", "Memory B cells expand and affinity-matured clones dominate the secondary response" ], "answer": 2, "explanation": "Histamine and other mediators are rapidly released. Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects." }, { "id": "immunity-allergy-integrated", "chapter": "Immunity", "difficulty": "Challenge", "stem": "Which paired outcome and explanation best follows from this condition: an allergen cross-links IgE on sensitized mast cells?", "options": [ "Immune rejection can damage the graft — Alloreactive lymphocytes activate cytotoxic and inflammatory pathways", "Established antibodies and memory cells become less effective — New epitopes are poorly recognized by clones selected against earlier variants", "Antibody concentration and average affinity rise rapidly — Memory B cells expand and affinity-matured clones dominate the secondary response", "Histamine and other mediators are rapidly released — Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects" ], "answer": 3, "explanation": "Histamine and other mediators are rapidly released. Mast-cell degranulation produces vasodilation, permeability and smooth-muscle effects." }, { "id": "immunity-transplant-outcome", "chapter": "Immunity", "difficulty": "Challenge", "stem": "After recipient T cells recognize non-self MHC on a transplanted organ, which observation is most likely?", "options": [ "Immune rejection can damage the graft", "Established antibodies and memory cells become less effective", "Antibody concentration and average affinity rise rapidly", "Many pathogens are prevented from entering tissues" ], "answer": 0, "explanation": "Immune rejection can damage the graft. Alloreactive lymphocytes activate cytotoxic and inflammatory pathways." }, { "id": "immunity-transplant-cause", "chapter": "Immunity", "difficulty": "Challenge", "stem": "A learner records that immune rejection can damage the graft. Which preceding event best accounts for it?", "options": [ "A pathogen repeatedly changes exposed antigenic structures", "Recipient T cells recognize non-self MHC on a transplanted organ", "A vaccine booster re-exposes a person to the same antigen", "Intact keratinized skin covers the body surface" ], "answer": 1, "explanation": "Immune rejection can damage the graft. Alloreactive lymphocytes activate cytotoxic and inflammatory pathways." }, { "id": "immunity-transplant-mechanism", "chapter": "Immunity", "difficulty": "Challenge", "stem": "After recipient T cells recognize non-self MHC on a transplanted organ, which explanation best links the change to its outcome?", "options": [ "New epitopes are poorly recognized by clones selected against earlier variants", "Memory B cells expand and affinity-matured clones dominate the secondary response", "Alloreactive lymphocytes activate cytotoxic and inflammatory pathways", "Tightly joined cells, dryness and antimicrobial secretions create a physical and chemical barrier" ], "answer": 2, "explanation": "Immune rejection can damage the graft. Alloreactive lymphocytes activate cytotoxic and inflammatory pathways." }, { "id": "immunity-transplant-integrated", "chapter": "Immunity", "difficulty": "Challenge", "stem": "Which paired outcome and explanation best follows from this condition: recipient T cells recognize non-self MHC on a transplanted organ?", "options": [ "Many pathogens are prevented from entering tissues — Tightly joined cells, dryness and antimicrobial secretions create a physical and chemical barrier", "Established antibodies and memory cells become less effective — New epitopes are poorly recognized by clones selected against earlier variants", "Antibody concentration and average affinity rise rapidly — Memory B cells expand and affinity-matured clones dominate the secondary response", "Immune rejection can damage the graft — Alloreactive lymphocytes activate cytotoxic and inflammatory pathways" ], "answer": 3, "explanation": "Immune rejection can damage the graft. Alloreactive lymphocytes activate cytotoxic and inflammatory pathways." }, { "id": "immunity-antigenic-variation-outcome", "chapter": "Immunity", "difficulty": "Challenge", "stem": "A student models this change: A pathogen repeatedly changes exposed antigenic structures. What should the model predict first?", "options": [ "Established antibodies and memory cells become less effective", "Many pathogens are prevented from entering tissues", "Antibody concentration and average affinity rise rapidly", "The bacterium becomes enclosed and digested" ], "answer": 0, "explanation": "Established antibodies and memory cells become less effective. New epitopes are poorly recognized by clones selected against earlier variants." }, { "id": "immunity-antigenic-variation-cause", "chapter": "Immunity", "difficulty": "Challenge", "stem": "What is the most likely cause when established antibodies and memory cells become less effective?", "options": [ "A vaccine booster re-exposes a person to the same antigen", "A pathogen repeatedly changes exposed antigenic structures", "A phagocyte recognizes and surrounds a bacterium", "Intact keratinized skin covers the body surface" ], "answer": 1, "explanation": "Established antibodies and memory cells become less effective. New epitopes are poorly recognized by clones selected against earlier variants." }, { "id": "immunity-antigenic-variation-mechanism", "chapter": "Immunity", "difficulty": "Challenge", "stem": "After a pathogen repeatedly changes exposed antigenic structures, which explanation best links the change to its outcome?", "options": [ "Tightly joined cells, dryness and antimicrobial secretions create a physical and chemical barrier", "Memory B cells expand and affinity-matured clones dominate the secondary response", "New epitopes are poorly recognized by clones selected against earlier variants", "A phagosome fuses with enzyme-containing lysosomes" ], "answer": 2, "explanation": "Established antibodies and memory cells become less effective. New epitopes are poorly recognized by clones selected against earlier variants." }, { "id": "immunity-antigenic-variation-integrated", "chapter": "Immunity", "difficulty": "Challenge", "stem": "Which paired outcome and explanation best follows from this condition: a pathogen repeatedly changes exposed antigenic structures?", "options": [ "Antibody concentration and average affinity rise rapidly — Memory B cells expand and affinity-matured clones dominate the secondary response", "The bacterium becomes enclosed and digested — A phagosome fuses with enzyme-containing lysosomes", "Many pathogens are prevented from entering tissues — Tightly joined cells, dryness and antimicrobial secretions create a physical and chemical barrier", "Established antibodies and memory cells become less effective — New epitopes are poorly recognized by clones selected against earlier variants" ], "answer": 3, "explanation": "Established antibodies and memory cells become less effective. New epitopes are poorly recognized by clones selected against earlier variants." }, { "id": "immunity-booster-outcome", "chapter": "Immunity", "difficulty": "Challenge", "stem": "Which immediate result is most consistent with this condition: A vaccine booster re-exposes a person to the same antigen?", "options": [ "Antibody concentration and average affinity rise rapidly", "The bacterium becomes enclosed and digested", "Local blood flow and capillary permeability increase", "Many pathogens are prevented from entering tissues" ], "answer": 0, "explanation": "Antibody concentration and average affinity rise rapidly. Memory B cells expand and affinity-matured clones dominate the secondary response." }, { "id": "immunity-booster-cause", "chapter": "Immunity", "difficulty": "Challenge", "stem": "Which condition would most specifically produce this result: antibody concentration and average affinity rise rapidly?", "options": [ "Intact keratinized skin covers the body surface", "A vaccine booster re-exposes a person to the same antigen", "A phagocyte recognizes and surrounds a bacterium", "Damaged tissue releases inflammatory mediators" ], "answer": 1, "explanation": "Antibody concentration and average affinity rise rapidly. Memory B cells expand and affinity-matured clones dominate the secondary response." }, { "id": "immunity-booster-mechanism", "chapter": "Immunity", "difficulty": "Challenge", "stem": "After a vaccine booster re-exposes a person to the same antigen, which explanation best links the change to its outcome?", "options": [ "Tightly joined cells, dryness and antimicrobial secretions create a physical and chemical barrier", "A phagosome fuses with enzyme-containing lysosomes", "Memory B cells expand and affinity-matured clones dominate the secondary response", "Vasodilation and endothelial changes deliver plasma proteins and leukocytes" ], "answer": 2, "explanation": "Antibody concentration and average affinity rise rapidly. Memory B cells expand and affinity-matured clones dominate the secondary response." }, { "id": "immunity-booster-integrated", "chapter": "Immunity", "difficulty": "Challenge", "stem": "Which paired outcome and explanation best follows from this condition: a vaccine booster re-exposes a person to the same antigen?", "options": [ "Many pathogens are prevented from entering tissues — Tightly joined cells, dryness and antimicrobial secretions create a physical and chemical barrier", "The bacterium becomes enclosed and digested — A phagosome fuses with enzyme-containing lysosomes", "Local blood flow and capillary permeability increase — Vasodilation and endothelial changes deliver plasma proteins and leukocytes", "Antibody concentration and average affinity rise rapidly — Memory B cells expand and affinity-matured clones dominate the secondary response" ], "answer": 3, "explanation": "Antibody concentration and average affinity rise rapidly. Memory B cells expand and affinity-matured clones dominate the secondary response." }, { "chapter": "Immunity", "id": "applied-secondary-response", "difficulty": "Standard", "stem": "Which explanation best fits the response pattern?", "options": [ "Antigen-specific memory produced by the first exposure", "The second dose contains no antigen", "Innate skin barriers alone manufacture antibodies", "Every antibody molecule divides into two" ], "answer": 0, "explanation": "A faster, stronger response to the same antigen is consistent with memory lymphocytes formed during the first adaptive response.", "visual": { "kind": "table", "caption": "Same antigen; illustrative antibody response", "headers": [ "Exposure", "Days to detectable antibody", "Peak relative level" ], "rows": [ [ "First", "7", "20" ], [ "Second", "2", "120" ] ] } }, { "chapter": "Immunity", "id": "applied-passive-active", "difficulty": "Standard", "stem": "A person receives ready-made antibodies. Which feature distinguishes this protection from vaccination-induced active immunity?", "options": [ "A delayed response requiring weeks before any antibody is present", "Immediate protection without the recipient generating those antibodies or memory from the transfer itself", "Permanent protection guaranteed after one dose", "Transfer of a complete new immune system" ], "answer": 1, "explanation": "Transferred antibodies can act quickly but are eventually broken down. The transfer itself does not create antigen-specific memory in the recipient." }, { "chapter": "Immunity", "id": "applied-antibiotic-choice", "difficulty": "Foundation", "stem": "Why does an antibiotic that blocks bacterial cell-wall synthesis fail to target influenza replication directly?", "options": [ "Influenza replicates without a genome", "All viruses have thicker peptidoglycan walls", "Influenza does not build a bacterial peptidoglycan wall", "Antibiotics cannot enter any human tissue" ], "answer": 2, "explanation": "The drug’s target is a bacterial structure absent from influenza. A therapy needs a relevant target; this does not imply antibiotics never have a role in a separate bacterial coinfection." }, { "chapter": "Immunity", "id": "applied-specificity-control", "difficulty": "Challenge", "stem": "After immunisation against antigen P, an animal responds rapidly to P but slowly to unrelated antigen Q. What does this comparison demonstrate most directly?", "options": [ "Conversion of P into Q", "Absence of all innate immunity", "Equal antibody binding to every antigen", "Specificity of adaptive memory" ], "answer": 3, "explanation": "The stronger repeat response is selective for the previously encountered antigen. The unfamiliar antigen still requires an initial adaptive response." } ] }