Biology

Human Immunity and Blood

2,096 Questions

Human immunity and blood questions cover the physiological mechanisms protecting the body against diseases and the components of blood. Topics include blood groups, cell mediated immunity, monoclonal antibodies, and blood coagulation. These biology topics frequently appear in general science sections of competitive exams.

Blood groupsCell mediated immunityMonoclonal antibodiesBlood coagulationCancer immunology

Human Immunity and Blood Questions

Multiple choice

Which type of hypersensitivity reaction is characterized by the activation of cytotoxic T cells?

  1. Type I

  2. Type II

  3. Type III

  4. Type IV
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Type II hypersensitivity reactions are characterized by the activation of cytotoxic T cells, which can directly kill target cells.

Multiple choice

Which type of immune response is primarily involved in allergies and asthma?

  1. Cell-mediated immunity

  2. Humoral immunity

  3. Innate immunity

  4. Adaptive immunity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Adaptive immunity, specifically the Th2-mediated immune response, plays a crucial role in allergies and asthma.

Multiple choice

Which cell type is primarily responsible for the immediate hypersensitivity reaction in allergies?

  1. Neutrophils

  2. Macrophages

  3. Mast cells

  4. Dendritic cells
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Mast cells are the primary effector cells in immediate hypersensitivity reactions, releasing inflammatory mediators upon allergen binding to IgE.

Multiple choice

What is the role of Th2 cells in allergic responses?

  1. Producing antibodies against pathogens

  2. Activating cytotoxic T cells

  3. Promoting inflammation and IgE production

  4. Suppressing immune responses
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Th2 cells promote inflammation and IgE production, contributing to the allergic response.

Multiple choice

Which cytokine is primarily responsible for eosinophil recruitment and activation in allergic inflammation?

  1. Interleukin-4 (IL-4)

  2. Interleukin-5 (IL-5)

  3. Interleukin-6 (IL-6)

  4. Tumor necrosis factor-alpha (TNF-alpha)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Interleukin-5 (IL-5) is the primary cytokine responsible for eosinophil recruitment and activation in allergic inflammation.

Multiple choice

Which cell type is primarily responsible for airway remodeling in asthma?

  1. Eosinophils

  2. Neutrophils

  3. Mast cells

  4. Airway smooth muscle cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Airway smooth muscle cells are primarily responsible for airway remodeling in asthma, leading to increased airway responsiveness and airflow obstruction.

Multiple choice

Which type of immune response involves the production of antibodies?

  1. Humoral immune response

  2. Cell-mediated immune response

  3. Innate immune response

  4. Adaptive immune response
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The humoral immune response is the part of the adaptive immune system that involves the production of antibodies by B cells.

Multiple choice

Which region of an antibody molecule is responsible for binding to specific antigens?

  1. Fab region

  2. Fc region

  3. Hinge region

  4. CDR region
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The CDR (complementarity-determining region) is the part of the antibody molecule that is responsible for binding to specific antigens.

Multiple choice

What is the role of the Fc region of an antibody molecule?

  1. Binding to specific antigens

  2. Activating complement proteins

  3. Binding to Fc receptors on immune cells

  4. Neutralizing toxins
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Fc region of an antibody molecule binds to Fc receptors on immune cells, which triggers various immune responses, such as phagocytosis and antibody-dependent cell-mediated cytotoxicity.

Multiple choice

Which class of antibodies is most abundant in the blood?

  1. IgG

  2. IgA

  3. IgM

  4. IgD
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

IgG is the most abundant class of antibodies in the blood, accounting for approximately 75% of all antibodies.

Multiple choice

Which class of antibodies is primarily found in mucosal secretions, such as saliva and tears?

  1. IgG

  2. IgA

  3. IgM

  4. IgE
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

IgA is the primary class of antibodies found in mucosal secretions, where it helps to protect against infections at mucosal surfaces.

Multiple choice

Which class of antibodies is involved in allergic reactions?

  1. IgG

  2. IgA

  3. IgM

  4. IgE
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

IgE is the class of antibodies involved in allergic reactions. It binds to allergens and triggers the release of histamine and other inflammatory mediators from mast cells and basophils.

Multiple choice

What is the role of memory B cells in the immune response?

  1. They produce antibodies immediately upon re-exposure to an antigen

  2. They help to activate T cells

  3. They differentiate into plasma cells

  4. They produce cytokines
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Memory B cells are a type of B cell that is generated during an immune response. They remain in the body after the infection has been cleared and can quickly produce antibodies upon re-exposure to the same antigen.

Multiple choice

What are monoclonal antibodies?

  1. Antibodies produced by a single B cell clone

  2. Antibodies produced by multiple B cell clones

  3. Antibodies produced by T cells

  4. Antibodies produced by macrophages
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Monoclonal antibodies are antibodies produced by a single B cell clone. They are identical in structure and specificity, and they can be produced in large quantities using hybridoma technology.

Multiple choice

Which MHC molecule is responsible for presenting antigens to CD8+ T cells?

  1. MHC class I

  2. MHC class II

  3. MHC class III

  4. MHC class IV
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

MHC class I molecules are expressed on all nucleated cells and present antigens to CD8+ T cells, which are cytotoxic and can kill infected cells.