[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fXZgsRXUTNnXh6EmYzrP7FSzsMbeRaBfAdO98HgBTDPg":32,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":90},[4,8,12,16,20,24,28],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Abbreviations","abbreviations","\u002Fabbreviations\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"type":33,"data":34},"blog",{"slug":35,"title":36,"description":36,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":39,"lastUpdatedDate":40,"draft":41,"category":42,"image":37,"body":43,"faq":44,"tags":45,"related":47},"mcq-in-medical-microbiology-immunology-mcqs-1-10","Immunology MCQs (1-10): Answers with Explanations",null,"Acharya Tankeshwar","2013-01-14","2026-07-12",false,"mcqs","### Immunology Practice Questions (1–10)\n\n**1. Specific immunity can be acquired either naturally or artificially and involves:**\n\na. All of the below\n\nb. Antibodies\n\nc. Antigens\n\nd. The classical complement pathway\n\n**2. Which DOES NOT provide long-term immunity?**\n\na. Artificially acquired active immunity\n\nb. Artificially acquired passive immunity\n\nc. Naturally acquired active immunity\n\nd. None of the above\n\n**3. An epitope is:**\n\na. A B-cell\n\nb. A hapten\n\nc. An antibody\n\nd. The antigen determinant site\n\n![](https:\u002F\u002Fassets.microbeonline.com\u002Fcontent\u002Fmcqs-in-medical-microbiology-immunology-1-to-10.png)![](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fmcqs-in-medical-microbiology-immunology-1-to-10.png)**4. An immunoglobulin is a:**\n\na. Carbohydrate\n\nb. Fatty acid\n\nc. Glycoprotein\n\nd. Protein\n\n**5. Isotypes refer to variations in the:**\n\na. Heavy chain constant region\n\nb. Heavy chain variable region\n\nc. Light chain constant region\n\nd. Light chain variable region\n\n**6. The Fc region mediates all of the below EXCEPT binding to:**\n\na. Antigen\n\nb. Lysosomes\n\nc. Some phagocytic cells\n\nd. Various cells of the immune system\n\n**7. Which of the following is the major immunoglobulin in human serum, accounting for 80% of the immunoglobulin pool?**\n\na. IgA\n\nb. IgD\n\nc. IgG\n\nd. IgM\n\n**8. Which immunoglobulin is the least prevalent?**\n\na. IgA\n\nb. IgD\n\nc. IgE\n\nd. IgM\n\n**9. Which of the following is useful to STIMULATE antibody production?**\n\na. An adjuvant\n\nb. A hapten\n\nc. Antiserum\n\nd. Purified antigen\n\ne. Crude antigen\n\n**10. Compared to the secondary antibody response, the primary response:**\n\na. Attains a higher IgG titer\n\nb. Has a longer lag phase\n\nc. Persists for a longer plateau period\n\nd. Produces antibodies with a higher affinity for the antigen\n\n### Answer Key & Explanations\n\n**1. Correct Answer: a (All of the below)**\n\n- **Explanation:** Specific (adaptive) immunity relies fundamentally on the interaction between foreign **antigens** and host-produced **antibodies**. Furthermore, when these specific antibodies bind to their target antigens, they trigger the **classical complement pathway** to clear the pathogen, making all the listed options integral components of the adaptive response.\n\n**2. Correct Answer: b (Artificially acquired passive immunity)**\n\n- **Explanation:** Passive immunity involves the direct transfer of pre-formed antibodies (such as administering intravenous immunoglobulin or anti-venom) into a recipient. Because the host's own immune system is never activated to undergo clonal expansion or produce memory cells, protection disappears as soon as the infused proteins are naturally metabolized.\n\n**3. Correct Answer: d (The antigen determinant site)**\n\n- **Explanation:** An **epitope** is the exact structural and chemical site on the surface of a macromolecular antigen that is recognized and bound by a specific B-cell receptor, T-cell receptor, or antibody molecule. It is the minimal unit that defines antigenic specificity.\n\n**4. Correct Answer: c (Glycoprotein)**\n\n- **Explanation:** Biochemically, immunoglobulins are classified as **glycoproteins**. They consist of a basic polypeptide structure containing two heavy and two light chains held together by disulfide bonds, interspersed with covalently attached carbohydrate groups localized primarily along the constant regions.\n\n**5. Correct Answer: a (Heavy chain constant region)**\n\n- **Explanation:** Immunoglobulin **isotypes** represent the structural variations within the **constant regions of the heavy chains** that are common to all healthy individuals of a species. These variations determine the broad class of the antibody (IgM, IgG, IgA, IgE, or IgD) and dictate its structural arrangement and biological effector pathways.\n\n**6. Correct Answer: a (Antigen)**\n\n- **Explanation:** The **Fc (Fragment crystallizable) region** of an antibody does *not* bind to antigens. Antigen binding is exclusively handled by the two **Fab (Fragment antigen-binding)** regions, which contain the hypervariable loops. Instead, the Fc tail anchors into Fc receptors found on phagocytes, mast cells, and lysosomes, and initiates complement activation.\n\n**7. Correct Answer: c (IgG)**\n\n- **Explanation:** **IgG** is the dominant antibody class circulating in human blood serum and extravascular tissues, structurally accounting for approximately **80%** of the total immunoglobulin pool. Its abundance allows it to serve as the baseline shield against circulating bacteria, toxins, and viruses.\n\n**8. Correct Answer: c (IgE)**\n\n- **Explanation:** **IgE** is the least prevalent antibody class in normal human serum, often present in trace concentrations. This is because IgE molecules are heavily sequestered out of circulation, being tightly bound to high-affinity Fc-epsilon receptors located on the surfaces of tissue mast cells and circulating basophils.\n\n**9. Correct Answer: a (An adjuvant)**\n\n- **Explanation:** An **adjuvant** is a substance formulated into a vaccine mixture to non-specifically enhance and **stimulate a more robust antibody production**. It works by extending the biological half-life of the antigen (depot effect) or by directly stimulating local innate immune cells via pattern recognition pathways. A hapten cannot stimulate an immune response on its own, and antiserum provides passive antibodies rather than stimulating production.\n\n**10. Correct Answer: b (Has a longer lag phase)**\n\n- **Explanation:** When the immune system encounters a novel antigen for the very first time, it lacks an established army of memory cells. Consequently, the **primary immune response requires a longer lag phase** (often 3 to 5 days) for naive lymphocytes to recognize the antigen, undergo clonal expansion, and differentiate into effector plasma cells. Conversely, secondary responses feature a rapid lag phase, higher affinity, and much higher titers.",[],[46],"immunology-mcqs",[48,54,61,67,72,78,84],{"slug":49,"title":50,"description":50,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":51,"lastUpdatedDate":40,"draft":41,"category":42,"image":37,"faq":52,"tags":53},"multiple-choice-questions-on-basic-immunology-concepts","MCQs Immunology (41-55): Basic Immunology with Answers","2013-01-29",[],[46],{"slug":55,"title":56,"description":56,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":57,"lastUpdatedDate":40,"draft":41,"category":42,"image":58,"faq":59,"tags":60},"mcq-medical-microbiology-immunology-21-30","MCQs in Immunology (21-30): Antibodies-I (Answers with Explanations)","2013-01-15","https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fmcqs-medical-microbiology-immunology-21-30.png",[],[46],{"slug":62,"title":63,"description":63,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":57,"lastUpdatedDate":40,"draft":41,"category":42,"image":64,"faq":65,"tags":66},"mcqs-in-immunology-complement-system-31-40","MCQs Immunology (31-40): Complement System with Answers","https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fmcqs-immunology-complement-system-with-answers.png",[],[46],{"slug":68,"title":69,"description":69,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":39,"lastUpdatedDate":40,"draft":41,"category":42,"image":37,"faq":70,"tags":71},"mcq-in-medical-microbiology-immunology-mcqs-11-20","Immunology MCQs (11-20): Answers with Explanations",[],[46],{"slug":73,"title":74,"description":74,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":75,"lastUpdatedDate":40,"draft":41,"category":42,"image":37,"faq":76,"tags":77},"mcq-in-microbiology-immunology-questions-and-answers-with-explanation","MCQ in Immunology (71-85): Basic Concepts Answers with Explanation","2012-11-27",[],[46],{"slug":79,"title":80,"description":80,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":81,"lastUpdatedDate":40,"draft":41,"category":42,"image":37,"faq":82,"tags":83},"mcq-immunology-antibodies","MCQ Immunology (86-100): Antibodies-II with Answers","2012-04-10",[],[46],{"slug":85,"title":86,"description":86,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":87,"lastUpdatedDate":40,"draft":41,"category":42,"image":37,"faq":88,"tags":89},"mcq-immunology-3","MCQ Immunology (56-70): Hypersensitivity Answers with Explanations","2010-04-18",[],[46],[91,97,104,109,113,117,122,127,131,135],{"slug":92,"name":38,"description":93,"image":94,"body":95,"postCount":96},"acharya-tankeshwar","Editor-in-chief","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Ftankeshwar-acharya-author-microbeonline.jpg","***Tankeshwar Acharya, MSc (Medical Microbiology)***\n\n*Tankeshwar Acharya is an Assistant Professor in the Department of Microbiology at Patan Academy of Health Sciences (PAHS), Nepal, where he has been teaching and practicing clinical microbiology for over 14 years. He is the founder of Microbe Online, one of the leading free microbiology education resources on the web, covering bacteriology, mycology, parasitology, immunology, and clinical laboratory diagnostics written from direct experience in both the classroom and the diagnostic laboratory.*",433,{"slug":98,"name":99,"description":100,"image":101,"body":102,"postCount":103},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",81,{"slug":105,"name":106,"description":107,"image":37,"body":37,"postCount":108},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor",32,{"slug":110,"name":111,"description":107,"image":37,"body":37,"postCount":112},"samikshya-acharya","Samikshya Acharya",20,{"slug":114,"name":115,"description":107,"image":37,"body":37,"postCount":116},"alisha-tripathi","Alisha Tripathi",6,{"slug":118,"name":119,"description":120,"image":37,"body":37,"postCount":121},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor",10,{"slug":123,"name":124,"description":125,"image":37,"body":37,"postCount":126},"guest-author","Guest Author","Guest Author \u002F Contributor",2,{"slug":128,"name":129,"description":107,"image":37,"body":37,"postCount":130},"srijana-khanal","Srijana Khanal",18,{"slug":132,"name":133,"description":125,"image":37,"body":37,"postCount":134},"dr-poonam-acharya","Dr. Poonam Acharya",1,{"slug":136,"name":137,"description":107,"image":37,"body":138,"postCount":139},"nisha-rijal","Nisha Rijal","**Nisha Rijal** is a microbiologist and quality assurance specialist. She served for nearly 12 years as a microbiologist at the National Public Health Laboratory (NPHL), Nepal's national reference laboratory, and continues to work as a consultant microbiologist in international public health organization. ",51]