Biology

Human Immunity and Blood

2,051 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

What is the role of MHC molecules in the immune system?

  1. To produce antibodies

  2. To destroy infected cells

  3. To activate complement proteins

  4. To present antigens to immune cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

MHC molecules, also known as major histocompatibility complex molecules, are proteins that are expressed on the surface of cells. They play a crucial role in the immune system by presenting antigens to immune cells, such as T cells, which can then recognize and respond to the antigens.

Multiple choice

Which type of immune response involves the production of antibodies by B cells?

  1. Cell-mediated immunity

  2. Humoral immunity

  3. Innate immunity

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

Humoral immunity is the antibody-mediated immune response. It involves the production of antibodies by B cells and plasma cells in response to the presence of an antigen. Antibodies bind to antigens, marking them for destruction by other components of the immune system.

Multiple choice

What is the role of dendritic cells in the immune system?

  1. To produce antibodies

  2. To destroy infected cells

  3. To activate complement proteins

  4. To present antigens to immune cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Dendritic cells are a type of antigen-presenting cell that plays a crucial role in the immune system. They capture and process antigens, and then present them to T cells, which can then recognize and respond to the antigens.

Multiple choice

Which type of immune response involves the activation of T cells?

  1. Cell-mediated immunity

  2. Humoral immunity

  3. Innate immunity

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

Cell-mediated immunity is the T cell-mediated immune response. It involves the activation of T cells, which recognize and destroy infected cells, as well as helping B cells differentiate into plasma cells, which produce antibodies.

Multiple choice

What is the role of natural killer cells in the immune system?

  1. To produce antibodies

  2. To destroy infected cells

  3. To activate complement proteins

  4. To help B cells differentiate into plasma cells
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Natural killer cells are a type of cytotoxic lymphocyte that plays a crucial role in the immune system. They recognize and destroy infected cells and tumor cells, without the need for prior sensitization to the specific antigen.

Multiple choice

What is the mechanism of immediate hypersensitivity reactions?

  1. Activation of complement cascade

  2. Release of histamine and other mediators from mast cells and basophils

  3. Formation of immune complexes

  4. Activation of cytotoxic T cells
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Immediate hypersensitivity reactions are mediated by the release of histamine and other mediators from mast cells and basophils upon exposure to an allergen.

Multiple choice

Which type of hypersensitivity reaction is characterized by the formation of immune complexes?

  1. Type I

  2. Type II

  3. Type III

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

Type III hypersensitivity reactions are characterized by the formation of immune complexes, which can activate complement and lead to tissue damage.

Multiple choice

What is the most common type of delayed hypersensitivity reaction?

  1. Contact dermatitis

  2. Tuberculin skin test

  3. Graft-versus-host disease

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

Contact dermatitis is the most common type of delayed hypersensitivity reaction. It is caused by direct contact with an allergen, such as poison ivy or nickel.

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.