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 C4bp in the regulation of the complement system?

  1. Activates C3 convertase

  2. Inhibits the alternative complement pathway

  3. Stabilizes the C5 convertase complex

  4. Binds to foreign cell surfaces to initiate opsonization
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

C4bp (C4 binding protein) is a regulatory protein that inhibits the alternative complement pathway by binding to C4b and preventing its interaction with C2a, thereby preventing the formation of C3 convertase.

Multiple choice

What is the most common type of leukemia?

  1. Acute lymphoblastic leukemia (ALL)

  2. Acute myeloid leukemia (AML)

  3. Chronic lymphocytic leukemia (CLL)

  4. Chronic myeloid leukemia (CML)
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

ALL is the most common type of leukemia, accounting for about 25% of all cases.

Multiple choice

What is the most common type of allergic reaction?

  1. Anaphylaxis

  2. Hives

  3. Eczema

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

Hives are the most common type of allergic reaction. This occurs when the skin develops red, itchy welts.

Multiple choice

What is an antigen?

  1. A substance that triggers an immune response

  2. A type of white blood cell

  3. A protein produced by the immune system

  4. A type of antibody
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

An antigen is any substance that is recognized by the immune system and triggers an immune response.

Multiple choice

What are the two main types of antigens?

  1. Exogenous and endogenous

  2. Humoral and cell-mediated

  3. Primary and secondary

  4. Active and passive
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Exogenous antigens are those that enter the body from outside, while endogenous antigens are those that are produced inside the body.

Multiple choice

What is the role of antigen-presenting cells (APCs) in the immune response?

  1. To phagocytize antigens and present them to T cells

  2. To produce antibodies against antigens

  3. To release cytokines that activate other immune cells

  4. To destroy infected cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

APCs are specialized cells that phagocytize antigens and present them to T cells, which are essential for the activation of the adaptive immune response.

Multiple choice

What are the two main types of T cells involved in the immune response to antigens?

  1. Helper T cells and cytotoxic T cells

  2. Regulatory T cells and memory T cells

  3. Naive T cells and effector T cells

  4. Central T cells and peripheral T cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Helper T cells help to activate other immune cells, while cytotoxic T cells kill infected cells.

Multiple choice

What is the role of MHC molecules in the immune response to antigens?

  1. To present antigens to T cells

  2. To activate B cells

  3. To produce antibodies

  4. To destroy infected cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

MHC molecules are cell surface proteins that present antigens to T cells, which are essential for the activation of the adaptive immune response.

Multiple choice

What is the difference between humoral immunity and cell-mediated immunity?

  1. Humoral immunity is mediated by antibodies, while cell-mediated immunity is mediated by T cells

  2. Humoral immunity is effective against extracellular pathogens, while cell-mediated immunity is effective against intracellular pathogens

  3. Humoral immunity is short-lived, while cell-mediated immunity is long-lived

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Humoral immunity is mediated by antibodies, while cell-mediated immunity is mediated by T cells. Humoral immunity is effective against extracellular pathogens, while cell-mediated immunity is effective against intracellular pathogens. Humoral immunity is short-lived, while cell-mediated immunity is long-lived.

Multiple choice

What is the role of cytokines in the immune response to antigens?

  1. To activate and regulate immune cells

  2. To promote the differentiation of B cells into plasma cells

  3. To stimulate the production of antibodies

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cytokines are small proteins that activate and regulate immune cells, promote the differentiation of B cells into plasma cells, and stimulate the production of antibodies.

Multiple choice

What is the difference between an immune complex and an immune precipitate?

  1. An immune complex is a soluble complex of antigen and antibody, while an immune precipitate is an insoluble complex of antigen and antibody

  2. An immune complex is formed in the fluid phase, while an immune precipitate is formed on a cell surface

  3. An immune complex is smaller than an immune precipitate

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

An immune complex is a soluble complex of antigen and antibody, while an immune precipitate is an insoluble complex of antigen and antibody. An immune complex is formed in the fluid phase, while an immune precipitate is formed on a cell surface. An immune complex is smaller than an immune precipitate.

Multiple choice

What is the role of complement proteins in the immune response to antigens?

  1. To lyse infected cells

  2. To opsonize antigens for phagocytosis

  3. To activate the inflammatory response

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Complement proteins lyse infected cells, opsonize antigens for phagocytosis, and activate the inflammatory response.

Multiple choice

Which cells are responsible for recognizing and attacking foreign invaders?

  1. Red blood cells

  2. White blood cells

  3. Platelets

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

White blood cells, specifically lymphocytes, are responsible for recognizing and attacking foreign invaders through various mechanisms.

Multiple choice

Which type of immune response involves the production of antibodies?

  1. Innate immunity

  2. Adaptive immunity

  3. Humoral immunity

  4. Cell-mediated immunity
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Humoral immunity involves the production of antibodies by B cells, which are specific proteins that recognize and neutralize foreign antigens.

Multiple choice

Which immune cells are responsible for cell-mediated immunity?

  1. B cells

  2. T cells

  3. Natural killer cells

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

T cells, specifically cytotoxic T cells, are responsible for cell-mediated immunity by directly killing infected cells and tumor cells.