Adaptive Immunity Practice Questions
20 free Adaptive Immunity practice questions for the Microbiology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
What is adaptive immunity?
- A Immediate non-specific defense mechanism
- B Physical barrier defense
- C Chemical barrier defense
- D Specific immune response with memory
Correct answer: Specific immune response with memory
Adaptive immunity is a specific immune response that develops over time and provides memory. It allows the body to respond more effectively upon re-exposure to the same pathogen.
Which cells are primarily involved in adaptive immunity?
- A Neutrophils
- B Resident macrophages
- C B and T lymphocytes
- D Platelets
Correct answer: B and T lymphocytes
B and T lymphocytes are the key cells of adaptive immunity. They provide specificity and memory in immune responses.
What is the main function of B cells?
- A Phagocytosis
- B Killing infected cells
- C Antigen presentation
- D Antibody production
Correct answer: Antibody production
B cells differentiate into plasma cells that produce antibodies. These antibodies target specific antigens.
Which cells are responsible for cell-mediated immunity?
- A B cells
- B Red blood cells
- C T cells
- D Platelets
Correct answer: T cells
T cells mediate cellular immunity by directly killing infected cells or helping other immune cells. They are crucial for defense against intracellular pathogens.
What is an antigen?
- A A molecule that triggers immune response
- B A type of antibody produced by plasma cells
- C A white blood cell
- D A hormone
Correct answer: A molecule that triggers immune response
An antigen is any substance recognized as foreign by the immune system. It stimulates an immune response.
Which type of T cell directly kills infected cells?
- A Helper T cells
- B Regulatory T cells
- C Memory T cells
- D Cytotoxic T cells
Correct answer: Cytotoxic T cells
Cytotoxic T cells (CD8+) directly kill infected or abnormal cells. They recognize antigens presented by MHC class I molecules.
Which cells help activate B cells and other immune cells?
- A Helper T cells
- B Cytotoxic T cells
- C NK cells
- D Macrophages
Correct answer: Helper T cells
Helper T cells (CD4+) release cytokines that activate B cells and other immune cells. They play a central role in coordinating immune responses.
What is the role of antibodies?
- A Bind and neutralize antigens
- B Destroy DNA
- C Produce energy for immune cells
- D Digest proteins
Correct answer: Bind and neutralize antigens
Antibodies bind to specific antigens and neutralize them or mark them for destruction. They are produced by plasma cells.
Which immunoglobulin is most abundant in blood?
- A IgA
- B IgM
- C IgE
- D IgG
Correct answer: IgG
IgG is the most abundant antibody in the bloodstream. It plays a major role in long-term immunity and memory.
Which immunoglobulin is first produced during primary immune response?
- A IgG
- B IgA
- C IgE
- D IgM
Correct answer: IgM
IgM is the first antibody produced during the primary immune response. It indicates recent exposure to an antigen.
What is immunological memory?
- A Ability to respond faster on re-exposure
- B Loss of immune function
- C Increased antibody production upon first exposure
- D Cell death process
Correct answer: Ability to respond faster on re-exposure
Immunological memory allows the immune system to respond more rapidly and effectively upon re-exposure to the same antigen. It is a hallmark of adaptive immunity.
Which cells are responsible for long-term immunity?
- A Memory cells
- B Effector cells
- C Neutrophils
- D Macrophages
Correct answer: Memory cells
Memory B and T cells persist after an infection. They enable a quicker and stronger immune response upon re-exposure.
What is clonal selection?
- A Activation and proliferation of specific lymphocytes
- B Destruction of immune cells by pathogens in the body
- C Mutation of DNA
- D Cell death
Correct answer: Activation and proliferation of specific lymphocytes
Clonal selection involves the activation and multiplication of lymphocytes that recognize a specific antigen. This ensures targeted immune responses.
Which molecules present antigens to T cells?
- A Immunoglobulins
- B MHC molecules
- C Enzymes
- D Hormones
Correct answer: MHC molecules
Major histocompatibility complex (MHC) molecules present antigens to T cells. This is essential for T cell activation.
Which MHC class presents antigens to cytotoxic T cells?
- A MHC I
- B MHC II
- C MHC III
- D MHC IV
Correct answer: MHC I
MHC class I molecules present intracellular antigens to cytotoxic T cells. This allows detection of infected or abnormal cells.
Which MHC class presents antigens to helper T cells?
- A MHC I
- B MHC II
- C MHC III
- D MHC IV
Correct answer: MHC II
MHC class II molecules present extracellular antigens to helper T cells. This helps coordinate immune responses.
What is the role of plasma cells?
- A Kill infected cells
- B Produce antibodies
- C Phagocytose pathogens
- D Present antigens
Correct answer: Produce antibodies
Plasma cells are differentiated B cells that produce large amounts of antibodies. They are key players in humoral immunity.
Which type of immunity is antibody-mediated?
- A Cell-mediated immunity
- B Humoral immunity
- C Innate immunity
- D Passive immunity
Correct answer: Humoral immunity
Humoral immunity involves antibodies produced by B cells. It is effective against extracellular pathogens.
What is vaccination?
- A Directly destroying infectious pathogens
- B Inducing immune memory using antigens
- C Producing antibiotics
- D Destroying immune cells
Correct answer: Inducing immune memory using antigens
Vaccination introduces antigens to stimulate the immune system without causing disease. This leads to the formation of memory cells.
Which adaptive immune response is faster upon second exposure?
- A Primary response
- B Secondary response
- C Innate response
- D Inflammatory response
Correct answer: Secondary response
The secondary immune response is faster and stronger due to memory cells. It provides enhanced protection against previously encountered pathogens.