Question 1

Which of the following is involved in myasthenia gravis?

Accepted Answer

Answer reason: Myasthenia gravis is an autoimmune disorder in which antibodies most commonly target postsynaptic acetylcholine receptors at the neuromuscular junction, and thymic abnormalities (hyperplasia or thymoma) are frequently associated. The thymus is involved in T-cell education and can contribute to loss of immune tolerance, promoting autoantibody production. Clinical improvement in some patients after thymectomy supports its pathogenic role.
Category reason: This question tests the immunologic association and pathogenesis of myasthenia gravis (autoimmunity and thymic involvement), which aligns best with Immunology rather than nursing interventions.

Question 2

Which disease weakens the Immune system?

Accepted Answer

Answer reason: HIV infection progressively destroys CD4+ T-lymphocytes, causing impaired cell-mediated immunity. This immunodeficiency increases susceptibility to opportunistic infections and certain malignancies. Asthma is primarily an inflammatory airway disease, and malaria is an acute parasitic infection rather than a chronic immunodeficiency syndrome.
Category reason: This question tests foundational knowledge of how a specific disease affects immune function, which is best classified under Immunology rather than nursing interventions or prioritization.

Question 3

Which immunoglobulin is present in breast milk?

Accepted Answer

Answer reason: Secretory IgA is the predominant immunoglobulin in human breast milk and provides passive mucosal immunity to the infant. It helps protect the newborn’s gastrointestinal and respiratory tracts by neutralizing pathogens and toxins without causing significant inflammation. This is especially important because neonatal immune defenses and antibody production are still developing. IgE is associated with allergy, IgD is mainly a B-cell receptor, and IgM is more prominent in early primary immune responses and in serum rather than breast milk.
Category reason: This question tests knowledge of immunoglobulin classes and passive immunity via breast milk, which is a core concept in Immunology rather than nursing interventions or prioritization.

Question 4

Which type of sample is commonly used for the Next-Gen Basophil Activation Test (BAT) in food allergy diagnosis?

Accepted Answer

Answer reason: BAT measures activation markers on basophils after exposure to specific allergens, which requires intact, viable basophils. These cells are assessed by flow cytometry and are best maintained in a fresh anticoagulated whole-blood specimen, not in serum, urine, or saliva. Serum mainly supports antibody testing (e.g., specific IgE) rather than cellular activation assays. Therefore, whole blood is the standard sample type for BAT in food allergy workups.
Category reason: This question tests foundational knowledge of an immunologic diagnostic assay and the specimen type required for cellular (basophil) functional testing, which fits Immunology.

Question 5

In breastfeeds which antibody through breast milk?

Accepted Answer

Answer reason: A) IgA Secretory immunoglobulin is the predominant antibody in human colostrum and breast milk and provides passive mucosal immunity to the infant. It coats the gastrointestinal and respiratory mucosa, helping neutralize pathogens and toxins without provoking significant inflammation. This protection is especially important in newborns whose own antibody production and mucosal defenses are immature.
Category reason: This question tests knowledge of immunoglobulin classes and passive immunity transfer via breast milk, which is a core topic in Immunology.

Question 6

A patient with Mycobacterium tuberculosis infection develops granuloma formation. Which immune cell is primarily responsible for this response?

Accepted Answer

Answer reason: Granuloma formation in tuberculosis is a type IV (delayed) hypersensitivity reaction in which activated macrophages are the key effector cells that aggregate and transform into epithelioid cells and multinucleated giant cells. Th1 CD4+ T cells provide critical IFN-γ signaling to activate these macrophages, but the granuloma’s cellular architecture is mainly composed of them. Neutrophils are more prominent in acute pyogenic infections, CD8+ T cells are not the primary drivers of granuloma structure, and mast cells are associated with immediate hypersensitivity responses.
Category reason: This question tests the immune mechanism and cell types involved in granulomatous inflammation due to tuberculosis, which is core Immunology (foundational biomedical knowledge), not a nursing intervention or clinical judgment item.

Question 7

Which does the nurse determine is a specific line of defense against infection?

Accepted Answer

Answer reason: A specific line of defense refers to adaptive (acquired) immunity, which targets particular pathogens through antigen-specific B- and T-lymphocyte responses and immunologic memory. In contrast, mucous membranes, the urinary tract environment (e.g., flushing/low pH), and the integumentary system are nonspecific (innate) barriers that provide general protection against many organisms. Therefore, the option that represents a specific defense mechanism is the adaptive immune response.
Category reason: This item tests the distinction between nonspecific (innate) barriers and specific (adaptive) defenses against infection, which is a core concept of Immunology.

Question 8

Plasma Cells are Formed From?

Accepted Answer

Answer reason: B-Lymphocyte Plasma cells are terminally differentiated B cells that arise after antigen exposure and activation (often with T-helper cell support). Their primary function is to synthesize and secrete large amounts of immunoglobulin (antibodies), reflecting the humoral immune response. Monocytes differentiate into macrophages/dendritic cells, basophils mediate allergic/inflammatory responses, and T lymphocytes differentiate into effector T cells rather than antibody-secreting cells.
Category reason: This question tests the immune cell lineage and antibody-producing cell differentiation, which is a core concept of Immunology rather than nursing intervention or patient-care decision-making.

Question 9

Anaphylaxis is _____.?

Accepted Answer

Answer reason: Anaphylaxis is an acute, rapid-onset systemic hypersensitivity reaction, most commonly IgE-mediated, that can cause airway edema/bronchospasm and distributive shock from widespread vasodilation and capillary leak. Because it affects multiple organ systems and can progress quickly to respiratory failure or cardiovascular collapse, it is a medical emergency. Localized reactions, chronic inflammation, or mild drug reactions do not capture the systemic and life-threatening nature of anaphylaxis.
Category reason: This item tests the definition and immune mechanism of anaphylaxis (a systemic hypersensitivity reaction), which is foundational immunology rather than a nursing decision/intervention scenario.

Question 10

Cytokines are responsible for……?

Accepted Answer

Answer reason: They are signaling proteins released by immune and other cells that coordinate the inflammatory response by activating and recruiting leukocytes and increasing vascular permeability. Key examples (e.g., IL-1, TNF-α, IL-6) drive systemic and local inflammatory effects such as fever, acute-phase response, and tissue inflammation. Pain can occur secondary to inflammation via sensitization of nociceptors, but it is not the primary defining role among the listed choices.
Category reason: This item tests foundational knowledge about immune cell signaling mediators and their physiologic role in inflammatory responses, which is core Immunology rather than nursing care decisions.

Question 11

Which of the following are the properties of acquired immunity ? ;)?

Accepted Answer

Answer reason: Acquired (adaptive) immunity is characterized by antigen specificity mediated by B- and T-cell receptors, enabling targeted responses. It also has vast diversity due to gene rearrangements that generate many unique antigen receptors. Immunological memory results from long-lived memory lymphocytes, producing faster and stronger responses upon re-exposure, so all listed features are properties.
Category reason: This is a foundational question about defining features of adaptive immune responses (specificity, diversity, memory), which is core Immunology rather than a nursing intervention or safety decision.

Question 12

In the AIDS patient which cells are highly affected?

Accepted Answer

Answer reason: HIV primarily targets CD4+ T lymphocytes by binding to the CD4 receptor (with CCR5/CXCR4 co-receptors), leading to progressive depletion and dysfunction of these cells. Loss of CD4+ T-cell help impairs both cell-mediated immunity and coordination of humoral responses, predisposing to opportunistic infections and certain malignancies. Although macrophages can be infected and serve as reservoirs, the defining and most clinically significant depletion in AIDS is CD4+ T-helper cells.
Category reason: This tests foundational immune cell targets and mechanisms of HIV/AIDS, which is core Immunology rather than a nursing-care decision.

Question 13

Which of the following diseases induces immunity?

Accepted Answer

Answer reason: Recovery from certain acute viral infections can produce strong, long-lasting protective immunity due to robust immune memory responses. Smallpox (variola) classically confers durable immunity after infection, which is why vaccination with related vaccinia virus was highly effective. In contrast, jaundice is a symptom/sign rather than a single immunizing disease entity, diabetes is a metabolic disorder, and tuberculosis does not reliably induce sterilizing immunity and reinfection can occur.
Category reason: This tests principles of immune memory and natural immunity following infection, which is best categorized under Immunology rather than nursing interventions or care management.

Question 14

Plasma cells are derived from?

Accepted Answer

Answer reason: Plasma cells are the terminally differentiated effector form of B cells that develop after antigen exposure and appropriate helper signals. Their primary function is antibody (immunoglobulin) production, which is central to humoral immunity. Monocytes differentiate into macrophages/dendritic cells, basophils are granulocytes involved in hypersensitivity reactions, and T lymphocytes differentiate into cell-mediated immune effectors rather than antibody-secreting cells.
Category reason: This question tests immune cell lineage and function (B-cell differentiation into plasma cells), which is a foundational topic in Immunology rather than a nursing intervention decision.

Question 15

Which organ produces antibodies?

Accepted Answer

Answer reason: The spleen is a secondary lymphoid organ where B lymphocytes can be activated and differentiate into plasma cells that secrete immunoglobulins. It also filters blood-borne pathogens and supports immune surveillance through its white pulp. The sternum is a bone and does not itself generate antibodies, and the pancreas primarily has endocrine and digestive functions rather than antibody production.
Category reason: This question tests where antibodies (immunoglobulins) are generated within the immune system, which is a core concept of Immunology rather than a nursing intervention or care decision.

Question 16

The Term 'Immunity' means

Accepted Answer

Answer reason: Immunity refers broadly to the body’s ability to resist infection or disease through innate and adaptive defenses. It is not limited to a single mechanism such as an antigen–antibody reaction or passive transfer of maternal antibodies. Immunization is one method to develop acquired immunity, but it represents only a subset of the overall concept.
Category reason: This question asks for the definition of immunity, a core concept in how the body defends against disease, which falls under Immunology.

Question 17

What is the underlying cause of rheumatoid arthritis?

Accepted Answer

Answer reason: B. Autoimmune attack on synovial joints Rheumatoid arthritis is a systemic autoimmune disease in which immune-mediated inflammation targets the synovium, leading to synovial hypertrophy (pannus), cartilage destruction, and bone erosions. Uric acid crystal deposition instead describes gout, while primary cartilage wear is typical of osteoarthritis. Septic arthritis is due to infection and usually presents as an acute monoarthritis requiring urgent antimicrobial therapy and drainage.
Category reason: This question tests the immunologic pathogenesis of a disease (autoimmune synovitis) rather than nursing interventions or prioritization, so it fits foundational biomedical knowledge under Immunology.

Question 18

What type of immunity does a vaccine provide? Choose only ONE best answer.?

Accepted Answer

Answer reason: Vaccines introduce an antigen in a controlled way to stimulate the person’s own immune system to produce antibodies and memory cells. This is “active” because the host generates the immune response rather than receiving preformed antibodies. It is “artificially acquired” because the exposure occurs through immunization rather than natural infection. Passive immunity would involve administration of ready-made antibodies (e.g., immune globulin), which does not create durable immune memory.
Category reason: This question tests the classification of immunity types (active vs passive; natural vs artificial), which is a core concept in Immunology rather than a nursing action or prioritization scenario.

Question 19

Which is a live attenuated vaccine?

Accepted Answer

Answer reason: B. OPV Live attenuated vaccines contain weakened forms of the pathogen that can replicate enough to induce a strong, durable immune response. Oral polio vaccine is a classic live attenuated vaccine used to stimulate mucosal and systemic immunity. In contrast, DPT and tetanus toxoid are inactivated toxoid-based vaccines, and hepatitis B vaccine is a recombinant subunit vaccine. Live attenuated vaccines are generally avoided in significantly immunocompromised patients due to the risk of vaccine-derived infection.
Category reason: This item tests foundational knowledge of vaccine types (live attenuated vs toxoid vs recombinant subunit), which is an immunology/biomedical classification rather than a nursing intervention or prioritization scenario.

Question 20

HLA antigen is controlled by a region on chromosome No.?

Accepted Answer

Answer reason: HLA genes are located within the major histocompatibility complex (MHC) region, which is on the short arm of chromosome 6 (6p21). This locus encodes class I (HLA-A, -B, -C) and class II (HLA-DR, -DQ, -DP) molecules central to antigen presentation. Because transplant compatibility and many autoimmune associations depend on this region, chromosome 6 is the correct choice.
Category reason: This question tests foundational knowledge of where HLA/MHC genes are located in the genome, which is a core concept in immune system genetics and antigen presentation, fitting Immunology rather than nursing interventions.

Question 21

Vaccines which protect the effects of future infection?

Accepted Answer

Answer reason: C) Prophylactic Vaccine. These vaccines are designed to prevent disease by inducing immunity before exposure to a pathogen, thereby protecting against future infection. They stimulate adaptive immune memory (e.g., neutralizing antibodies and memory B/T cells) so that subsequent exposure leads to rapid, effective immune responses. By contrast, therapeutic vaccines are intended to treat existing disease, and “killed” and “toxoid” describe vaccine types rather than the preventive intent being asked.
Category reason: This is a foundational question about vaccine purpose (preventive vs therapeutic) and immune protection against future infection, which is core Immunology rather than nursing judgment or patient-care prioritization.

Question 22

Which vaccine can be given to an Aids Positive Child?

Accepted Answer

Answer reason: In children with HIV/AIDS, inactivated (killed) vaccines are generally safe and recommended because they cannot replicate and cause disease. DPT is an inactivated vaccine, so it can be administered even in immunocompromised patients. In contrast, BCG, OPV, and measles vaccines are live attenuated and may cause severe infection in significantly immunosuppressed children.
Category reason: This is a foundational immunization safety question focused on live vs inactivated vaccines in immunocompromised (HIV/AIDS) patients, which fits Immunology rather than nursing care prioritization or interventions.

Question 23

The main function of white blood cells is?

Accepted Answer

Answer reason: They protect the body by recognizing and responding to pathogens and abnormal cells through innate and adaptive immune mechanisms. Different leukocyte types perform roles such as phagocytosis, antibody production, and coordinating inflammation. In contrast, oxygen transport is primarily done by red blood cells via hemoglobin, clotting is mainly mediated by platelets and coagulation factors, and most hormone transport occurs bound to plasma proteins or dissolved in plasma.
Category reason: This question tests the core biological role of leukocytes in host defense, which is foundational immune-system knowledge rather than a nursing intervention scenario.

Question 24

Which type of immunity is passed from mother to child?

Accepted Answer

Answer reason: Maternal antibodies (primarily IgG) cross the placenta during pregnancy and provide the newborn immediate, short-term protection without the infant mounting their own immune response. Additional passive protection is provided via IgA in breast milk. Because the antibodies are received preformed and not produced by the child, this is passive immunity. Since it occurs through natural maternal transfer rather than medical administration, it is classified as natural.
Category reason: This tests mechanisms and classification of immune protection (active vs passive; natural vs artificial), which is a core concept in Immunology rather than a nursing care decision.

Question 25

Panel test is done to know?

Accepted Answer

Answer reason: Panel testing in immunohematology (e.g., antibody identification panels) is used to detect and identify unexpected antibodies present in a patient’s serum/plasma. The serum is reacted against a panel of reagent red cells with known antigen profiles to see the reaction pattern. This helps determine which alloantibody is present and guides selection of compatible blood for transfusion.
Category reason: This question tests understanding of immune principles and serologic testing (antibody detection in serum), which falls under Immunology rather than nursing care decision-making.

Question 26

Incomplete antibody :

Accepted Answer

Answer reason: In immunohematology, “incomplete” antibodies are those that do not directly agglutinate red blood cells in saline because they are smaller and typically react best at 37°C. These are usually IgG antibodies, which can sensitize RBCs and require antiglobulin (Coombs) reagent to demonstrate agglutination. By contrast, IgM antibodies are “complete” antibodies that readily cause direct agglutination at room temperature due to their pentameric structure.
Category reason: This tests foundational immune globulin properties (class-specific behavior such as complete vs incomplete antibodies), which is core Immunology rather than nursing care decision-making.

Question 27

Cold agglutination syndrome is due to ?

Accepted Answer

Answer reason: Cold agglutinin syndrome is typically mediated by antibodies that bind red blood cells at lower temperatures and activate complement. These are most often pentameric immunoglobulins with strong agglutinating capacity and efficient complement fixation, leading to hemolysis (commonly extravascular with C3b opsonization). This pattern is characteristic of primary cold agglutinin disease and some infections (e.g., Mycoplasma pneumoniae, EBV).
Category reason: This question tests the immunoglobulin class responsible for a specific immune-mediated hemolytic syndrome, which is a core concept in Immunology rather than nursing care decision-making.

Question 28

The first line of defense against parasites:

Accepted Answer

Answer reason: These cells are specialized for host defense against helminths and other parasites through degranulation of cytotoxic proteins (e.g., major basic protein) and antibody-dependent cellular cytotoxicity, often driven by IgE. They also participate in Th2-mediated immune responses that are characteristic of many parasitic infections. Neutrophils are primarily first responders to bacterial infection and acute inflammation, basophils are more associated with allergic mediator release, and lymphocytes provide adaptive immunity rather than being the key effector cell against large parasites.
Category reason: This question tests foundational immune cell function in parasitic defense, which is a core topic in Immunology rather than a nursing care decision or prioritization task.

Question 29

...... play a role in immediate and delayed hypersensitivity:

Accepted Answer

Answer reason: Immediate (type I) hypersensitivity is driven by IgE production with mast-cell/basophil activation, and this IgE class-switching depends on T-helper lymphocyte signaling. Delayed (type IV) hypersensitivity is directly mediated by sensitized T lymphocytes that recruit and activate macrophages, producing inflammation hours to days after exposure. Thus, lymphocytes are central to both immediate and delayed hypersensitivity mechanisms, whereas the other listed leukocytes are not the primary drivers of both types.
Category reason: This item tests immune cell roles in hypersensitivity reactions (type I and type IV), which is core content of Immunology rather than bedside nursing decision-making.

Question 30

Cell which participate in cell mediated immunity?

Accepted Answer

Answer reason: c- T- lymphocyte Cell-mediated immunity is primarily driven by T cells, including cytotoxic T cells that kill infected or abnormal cells and helper T cells that coordinate immune responses via cytokines. In contrast, B lymphocytes mediate humoral (antibody) immunity. Monocytes and neutrophils are important innate immune cells for phagocytosis and inflammation but are not the central mediators of cell-mediated adaptive immunity.
Category reason: This question tests core adaptive immune system function—distinguishing cell-mediated (T-cell) from humoral (B-cell) immunity—which belongs to Immunology.

Question 31

All are character of primary immune response except?

Accepted Answer

Answer reason: c- high level of Ab Primary immune responses are typically slower to develop and produce a lower peak antibody titer compared with secondary (memory) responses. They begin with activation of naïve B cells, followed by a lag phase before measurable antibody appears. The overall antibody levels are relatively low and of shorter duration, with initial predominance of IgM and less affinity maturation.
Category reason: This question tests fundamental features of primary vs secondary immune responses (naïve B-cell activation, antibody magnitude and duration), which is core Immunology rather than a patient-care decision.

Question 32

They are cytokines that regulate the interaction between lymphocyte and other leukocyte?

Accepted Answer

Answer reason: d- Interleukins Interleukins are a broad class of cytokines primarily produced by leukocytes that mediate communication between immune cells, especially coordinating interactions between lymphocytes and other leukocytes. They regulate activation, proliferation, differentiation, and trafficking of immune cells during innate and adaptive immune responses. By contrast, interferons mainly drive antiviral states and immune modulation, TNF is a key pro-inflammatory mediator, and “growth factors” is a nonspecific term not focused on leukocyte-to-leukocyte signaling.
Category reason: This question tests knowledge of cytokine classes and their roles in immune-cell communication, which is a core concept in Immunology rather than a nursing intervention or care decision.

Question 33

Reagenic AD:

Accepted Answer

Answer reason: Type I (immediate) hypersensitivity reactions—commonly implicated in allergic diseases and anaphylaxis—are mediated by IgE bound to mast cells and basophils. Allergen cross-linking triggers degranulation and release of histamine and other mediators, producing acute symptoms such as urticaria, bronchospasm, and hypotension. The other listed immunoglobulins are more associated with mucosal immunity (IgA), primary response/agglutination (IgM), and secondary response/opsonization and placental transfer (IgG).
Category reason: This item tests foundational knowledge of immunoglobulin classes and their role in hypersensitivity reactions, which is a core topic within Immunology rather than nursing care decision-making.

Question 34

Tuberculin test is ?

Accepted Answer

Answer reason: d- type IV hypersensitivity The tuberculin (PPD) skin test is a delayed hypersensitivity reaction mediated by sensitized T lymphocytes rather than antibodies. Induration peaks at about 48–72 hours due to cytokine-driven recruitment of macrophages and local inflammation. This pattern is characteristic of type IV (delayed) hypersensitivity, whereas types I–III are primarily antibody/immune-complex mediated and typically occur more rapidly.
Category reason: This question tests the immunologic mechanism underlying the tuberculin skin test and classification of hypersensitivity reactions, which is a core topic in Immunology rather than a nursing intervention/prioritization scenario.

Question 35

Which cell type is primarily destroyed in HIV infection?

Accepted Answer

Answer reason: HIV targets cells expressing the CD4 receptor, entering primarily CD4 T lymphocytes via co-receptors (CCR5/CXCR4) and causing progressive depletion. Loss of these cells impairs cell-mediated immunity and reduces coordination of humoral and innate responses, leading to opportunistic infections and AIDS-defining conditions. Although macrophages can be infected and act as reservoirs, the hallmark immunologic destruction is the decline in CD4 count.
Category reason: This question tests foundational knowledge of HIV pathogenesis and immune cell targets, which is primarily an Immunology topic rather than a nursing intervention or safety decision.

Question 36

The cell which is responsible for antibody production is?

Accepted Answer

Answer reason: B-lymphocytes They differentiate into plasma cells, which synthesize and secrete immunoglobulins as part of the humoral immune response. T-lymphocytes primarily mediate cellular immunity and help coordinate immune responses rather than producing immunoglobulins directly. Neutrophils and monocytes are phagocytes involved in innate defense, not antibody generation. Therefore, the antibody-producing lineage is derived from B cells.
Category reason: This question tests foundational immune system function—specifically which leukocyte lineage produces antibodies—so it belongs to Immunology under NursingScience rather than a nursing intervention/judgment domain.

Question 37

A client with systemic lupus erythematosus (SLE) reports joint pain, fever, and fatigue. Which lab value is most relevant?

Accepted Answer

Answer reason: C. ANA (antinuclear antibody) SLE is a systemic autoimmune disease characterized by autoantibody production, and ANA is a key screening marker that supports the diagnosis in the appropriate clinical context. Hematocrit may be abnormal in anemia of chronic disease or hemolysis but is not the most specific/central lab for SLE identification. BUN reflects renal function and is relevant if nephritis is suspected, but it is not the most relevant general lab for the classic systemic presentation described. Troponin is used for myocardial injury and would be targeted only if acute cardiac ischemia or myocarditis is suspected.
Category reason: This question primarily tests understanding of autoimmune serology and the laboratory marker associated with systemic lupus erythematosus, which is an immunologic concept rather than a nursing intervention/prioritization scenario.

Question 38

Herd immunity is related with?

Accepted Answer

Answer reason: Herd immunity is a population-level protection that occurs when enough individuals have immunity to reduce transmission of an infectious agent. Vaccination is the primary method used to create immunity in a large proportion of a community without requiring people to become infected. As immunization coverage rises, chains of transmission are interrupted, indirectly protecting those who are not immune (e.g., infants or immunocompromised patients). Sanitation and nutrition can reduce disease risk and improve host resilience, but they do not directly produce the immune protection threshold that defines herd immunity. Surgery is unrelated to community-wide immune protection against communicable diseases.

Question 39

Largest lymphatic organ is?

Accepted Answer

Answer reason: The core principle is that the spleen is the largest secondary lymphoid organ and a major site of immune surveillance of blood. It contains white pulp (lymphoid tissue) that mounts immune responses to blood-borne antigens and red pulp that filters aged or damaged erythrocytes. This combination of extensive lymphoid tissue and filtration function makes it the largest lymphatic organ overall. By contrast, lymph nodes and tonsils are smaller, regionally distributed lymphoid tissues, and the thymus is a primary lymphoid organ for T-cell maturation rather than the largest lymphatic organ.

Question 40

Which antibody type is the largest in size?

Accepted Answer

Answer reason: This class is typically secreted as a pentamer in serum (with a J chain), making it the highest–molecular weight antibody and the largest in size. Its multimeric form also explains its strong agglutination and high avidity early in primary immune responses. In contrast, IgG is a monomer and therefore substantially smaller despite being the most abundant in circulation.

Question 41

Which of the following antibodies are present in tears and saliva?

Accepted Answer

Answer reason: Tears and saliva are classic mucosal secretions where this antibody provides first-line neutralization of pathogens and toxins without strong inflammatory activation. In contrast, IgG predominates in serum and extracellular fluid, while IgM is mainly an early intravascular response antibody. IgE is associated with allergy and parasite defense rather than routine mucosal secretion defense.

Question 42

Which of the following components do not belong to the nonspecific humoral defense?

Accepted Answer

Answer reason: Antibodies are products of B lymphocytes and are highly antigen-specific, making them a hallmark of the adaptive (specific) humoral immune response. Therefore they do not belong to the nonspecific humoral defense category. A common confusion is with complement, which is innate even though it can be activated by antibody-containing immune complexes.

Question 43

Which is a Phagocytic Cell?

Accepted Answer

Answer reason: Macrophages are tissue-resident cells derived from monocytes and are among the most important professional phagocytes, using lysosomes and oxidative mechanisms to kill ingested microbes. Platelets (thrombocytes) primarily function in hemostasis and clot formation rather than microbial ingestion. RBCs are specialized for oxygen transport and lack organelles needed for phagocytosis.

Question 44

Most Specific antibody for SLE:-

Accepted Answer

Answer reason: Among the listed choices, this antibody is strongly associated with SLE and is also clinically useful because titers often correlate with disease activity, particularly lupus nephritis. SS-A (Ro) and SS-B (La) are more classically linked to Sjögren syndrome and can be seen in some SLE cases but are less specific. Anticentromere antibodies are typical of limited cutaneous systemic sclerosis (CREST), not SLE.

Question 45

Which of the following gives lifelong immunity after attack?

Accepted Answer

Answer reason: Mumps classically confers durable post-infection immunity compared with several bacterial toxin-mediated diseases. In contrast, tetanus and diphtheria are primarily toxin-mediated; infection does not reliably produce protective antibody levels, which is why vaccination and boosters are required. Typhoid can recur and may lead to a carrier state rather than consistent lifelong immunity.

Question 46

Which of the following is not a type of vaccine?

Accepted Answer

Answer reason: Killed (inactivated), live-attenuated, and toxoid preparations are established vaccine categories used to safely stimulate protective immunity. Steroids are immunosuppressive/anti-inflammatory drugs and do not function as antigenic preparations that induce protective immune memory. In fact, systemic steroid therapy can blunt vaccine responses rather than serve as a vaccine type.

Question 47

CRP, or C-reactive protein is produced in…..?

Accepted Answer

Answer reason:  CRP is a positive acute-phase reactant synthesized primarily by hepatocytes in response to inflammatory cytokines, especially IL-6. During infection, tissue injury, or other systemic inflammation, the liver rapidly increases CRP production, making it a widely used biomarker of inflammation. The other organs listed are not the principal site of acute-phase protein synthesis. A common confusion is thinking the involved organ system produces the marker, but acute-phase proteins are predominantly liver-derived regardless of where inflammation occurs.

Question 48

The immunity developed as a result of infection by pathogenic organism is?

Accepted Answer

Answer reason: This is the defining mechanism of active immunity and is typically longer lasting due to immunologic memory. Passive immunity instead involves receiving preformed antibodies (e.g., immunoglobulin, maternal IgG) and does not create memory. While infection-related immunity is also “naturally acquired,” the best single classification among the given choices is the active vs passive distinction, making this the most precise answer.

Question 49

A 34-year-old female has recently been diagnosed with an autoimmune disease. She has also recently discovered that she is pregnant. Which of the following is the only immunoglobulin that will provide protection to the fetus in the womb?

Accepted Answer

Answer reason: This transfer increases especially in the third trimester and supplies the fetus with systemic protection against pathogens the mother has immunity to. Other classes are primarily mucosal (IgA), cell-surface B-cell receptors (IgD), or involved in allergy/parasite responses and do not cross the placenta in meaningful amounts (IgE). This also explains why maternal autoantibodies of this class can affect the fetus (e.g., certain hemolytic or neonatal lupus phenomena).

Question 50

Cytokines are chemical messagers which ?

Accepted Answer

Answer reason: A core, widely tested function of many cytokines (e.g., IL-1, TNF-α, IL-6) is to amplify inflammatory pathways, driving fever, acute-phase responses, leukocyte adhesion, and chemotaxis. Direct killing of microorganisms is primarily performed by effector cells (neutrophils, macrophages, cytotoxic T cells) and complement, not by cytokines themselves. Antibiotics are produced by certain microorganisms or synthesized pharmacologically, and severe pain is more directly mediated by nociceptor activation and mediators like prostaglandins and bradykinin rather than being the defining role of cytokines.

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