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

Which immunoglobulin is primarily involved in Type II hypersensitivity reactions?

  1. IgA

  2. IgD

  3. IgG

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

IgG is the primary immunoglobulin involved in Type II hypersensitivity reactions, where antibodies bind to cell surface antigens and activate complement, leading to cell lysis.

Multiple choice

What is the complement system's role in Type III hypersensitivity reactions?

  1. It activates mast cells.

  2. It opsonizes pathogens for phagocytosis.

  3. It forms immune complexes with antigens.

  4. It directly lyses cells.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In Type III hypersensitivity reactions, the complement system plays a role in forming immune complexes with antigens, which can then deposit in tissues and cause inflammation.

Multiple choice

Which type of T cell is primarily involved in Type IV hypersensitivity reactions?

  1. Th1 cells

  2. Th2 cells

  3. Th17 cells

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

Th1 cells are the primary T cell subset involved in Type IV hypersensitivity reactions, where they release cytokines that activate macrophages and other immune cells to mediate delayed-type hypersensitivity responses.

Multiple choice

What is the mechanism of action of antihistamines in treating Type I hypersensitivity reactions?

  1. They inhibit the release of histamine from mast cells.

  2. They block the binding of IgE to mast cells.

  3. They activate the complement system.

  4. They suppress T cell responses.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Antihistamines work by inhibiting the release of histamine from mast cells, thereby reducing the inflammatory response associated with Type I hypersensitivity reactions.

Multiple choice

Which type of hypersensitivity reaction is characterized by the formation of granulomas?

  1. Type I

  2. Type II

  3. Type III

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

Type IV hypersensitivity reactions, particularly delayed-type hypersensitivity reactions, are characterized by the formation of granulomas, which are collections of immune cells that surround and attempt to contain foreign substances or pathogens.

Multiple choice

What is the role of T regulatory cells (Tregs) in hypersensitivity reactions?

  1. They activate mast cells.

  2. They promote inflammation.

  3. They suppress immune responses.

  4. They directly kill pathogens.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

T regulatory cells (Tregs) play a crucial role in regulating immune responses and preventing excessive inflammation. In hypersensitivity reactions, Tregs can suppress immune responses and help maintain immune tolerance.

Multiple choice

Which type of hypersensitivity reaction is associated with contact dermatitis?

  1. Type I

  2. Type II

  3. Type III

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

Type IV hypersensitivity reactions, specifically allergic contact dermatitis, are associated with contact dermatitis. This occurs when an individual comes into contact with an allergen, leading to a delayed-type hypersensitivity response characterized by skin inflammation and redness.

Multiple choice

What is the primary mechanism of desensitization in Type I hypersensitivity reactions?

  1. Blocking antibodies

  2. T cell suppression

  3. Mast cell degranulation

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

Desensitization in Type I hypersensitivity reactions primarily involves the administration of blocking antibodies, which bind to allergens and prevent their interaction with IgE antibodies on mast cells, thereby reducing the release of inflammatory mediators.

Multiple choice

Which food allergy can cause a life-threatening reaction called anaphylaxis?

  1. Peanut allergy

  2. Shellfish allergy

  3. Tree nut allergy

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

Peanut allergy can cause a life-threatening reaction called anaphylaxis.

Multiple choice

What is the term for the idea that our immune system can be overactive and attack our own tissues?

  1. Autoimmunity

  2. Allergy

  3. Asthma

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

Autoimmunity is the idea that our immune system can be overactive and attack our own tissues, leading to a variety of health problems.

Multiple choice

Which of the following is NOT a type of cytokine?

  1. Interleukins

  2. Interferons

  3. Antibodies

  4. Tumor necrosis factor
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Antibodies are produced by B cells and plasma cells, and they are not considered to be cytokines.

Multiple choice

Which cytokine is responsible for stimulating the differentiation of T helper cells?

  1. Interleukin-2

  2. Interleukin-4

  3. Interleukin-6

  4. Interleukin-10
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Interleukin-2 is a cytokine that is produced by activated T cells and other immune cells. It stimulates the differentiation of T helper cells, which are important for coordinating immune responses.

Multiple choice

Which cytokine is responsible for inhibiting the production of pro-inflammatory cytokines?

  1. Interleukin-10

  2. Interleukin-12

  3. Interleukin-18

  4. Interleukin-22
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Interleukin-10 is a cytokine that is produced by regulatory T cells and other immune cells. It inhibits the production of pro-inflammatory cytokines, such as interleukin-1, interleukin-6, and tumor necrosis factor, and it promotes the production of anti-inflammatory cytokines, such as interleukin-4 and interleukin-10.

Multiple choice

Which cytokine is responsible for stimulating the production of antibodies by B cells?

  1. Interleukin-4

  2. Interleukin-6

  3. Interleukin-10

  4. Interleukin-12
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Interleukin-4 is a cytokine that is produced by activated T helper cells and other immune cells. It stimulates the production of antibodies by B cells, and it also promotes the differentiation of B cells into plasma cells.

Multiple choice

Which cytokine is responsible for stimulating the production of interferon-gamma by natural killer cells?

  1. Interleukin-12

  2. Interleukin-15

  3. Interleukin-18

  4. Interleukin-21
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Interleukin-12 is a cytokine that is produced by macrophages, dendritic cells, and other immune cells. It stimulates the production of interferon-gamma by natural killer cells, which are important for controlling viral infections and tumor growth.