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 signaling pathway is activated in NK cells upon target cell recognition?

  1. MAPK pathway

  2. PI3K pathway

  3. Jak-STAT pathway

  4. NF-κB pathway
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The PI3K (Phosphoinositide 3-Kinase) pathway is activated in NK cells upon target cell recognition. This pathway regulates various cellular processes, including cell activation, proliferation, and cytotoxicity.

Multiple choice

What is the role of NK cells in regulating adaptive immune responses?

  1. They suppress T cell activation

  2. They promote B cell differentiation

  3. They enhance antibody production

  4. They stimulate dendritic cell maturation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

NK cells can stimulate the maturation and activation of dendritic cells, which are antigen-presenting cells that play a crucial role in initiating adaptive immune responses.

Multiple choice

Which transcription factor is essential for NK cell development and function?

  1. T-bet

  2. GATA-3

  3. RORγt

  4. FoxP3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

T-bet (T-box transcription factor expressed in T cells) is a key transcription factor that regulates NK cell development, maturation, and cytotoxic function.

Multiple choice

What is the term used to describe the phenomenon where NK cells become anergic or hyporesponsive after prolonged exposure to target cells?

  1. NK cell exhaustion

  2. NK cell tolerance

  3. NK cell anergy

  4. NK cell senescence
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

NK cell exhaustion refers to the state of functional impairment and hyporesponsiveness that can occur in NK cells after prolonged exposure to target cells or chronic stimulation.

Multiple choice

Which receptor on NK cells is involved in the recognition of antibody-coated target cells?

  1. FcγRIIIa (CD16)

  2. KIR (Killer cell immunoglobulin-like receptor)

  3. NKG2D (Natural cytotoxicity triggering receptor 2)

  4. CD56 (Neural cell adhesion molecule)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

FcγRIIIa (CD16) is an activating receptor expressed on NK cells that binds to the Fc portion of antibodies bound to target cells, triggering antibody-dependent cell-mediated cytotoxicity (ADCC).

Multiple choice

Which cytokine is produced by NK cells that can inhibit tumor growth and angiogenesis?

  1. Interferon-gamma (IFN-γ)

  2. Interleukin-4 (IL-4)

  3. Interleukin-10 (IL-10)

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

NK cells produce Interferon-gamma (IFN-γ), a cytokine that has anti-tumor effects by inhibiting tumor cell proliferation, inducing apoptosis, and suppressing angiogenesis.

Multiple choice

Which type of immune response is responsible for attacking and destroying infected cells?

  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
B Correct answer
Explanation

The cell-mediated immune response is responsible for attacking and destroying infected cells. It involves the activation of T cells, which can directly kill infected cells or release chemicals that attract other immune cells to the site of infection.

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 involves the production of antibodies, which are proteins that can bind to and neutralize pathogens. Antibodies are produced by B cells, which are activated by antigens.

Multiple choice

Which type of immune cell is responsible for producing memory cells?

  1. T cells

  2. B cells

  3. Macrophages

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

B cells are responsible for producing memory cells, which are long-lived cells that can quickly respond to a pathogen that the body has encountered before.

Multiple choice

Which type of immune cell is responsible for releasing histamine and other inflammatory mediators?

  1. T cells

  2. B cells

  3. Macrophages

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

Mast cells are responsible for releasing histamine and other inflammatory mediators, which are involved in the inflammatory response.

Multiple choice

What is the role of the spleen in the immune system?

  1. To produce antibodies

  2. To mature T cells

  3. To store immune cells

  4. To filter blood
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The spleen is responsible for filtering blood and removing old or damaged red blood cells, as well as foreign particles and pathogens.

Multiple choice

Which type of immune cell is responsible for producing natural killer cells?

  1. T cells

  2. B cells

  3. Macrophages

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

The bone marrow is responsible for producing natural killer cells, which are a type of white blood cell that can kill infected cells and tumor cells.

Multiple choice

Which type of immune response is responsible for providing protection against intracellular pathogens?

  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
B Correct answer
Explanation

The cell-mediated immune response is responsible for providing protection against intracellular pathogens, such as viruses and bacteria that live inside cells.

Multiple choice

What is the role of neutrophils in the inflammatory response?

  1. They phagocytose foreign particles

  2. They release histamine and serotonin

  3. They produce antibodies

  4. They activate complement proteins
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Neutrophils are phagocytic cells that engulf and destroy foreign particles, including bacteria and cellular debris. They are among the first cells to arrive at the site of inflammation.

Multiple choice

Which cytokine is primarily responsible for the vasodilation and increased vascular permeability seen in inflammation?

  1. Interleukin-1 (IL-1)

  2. Tumor necrosis factor-alpha (TNF-alpha)

  3. Interleukin-6 (IL-6)

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

Histamine is a potent vasodilator and increases vascular permeability, leading to the redness and swelling associated with inflammation. It is released by mast cells and basophils.