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 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.

Multiple choice

Which MHC molecule is responsible for presenting antigens to CD4+ 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
B Correct answer
Explanation

MHC class II molecules are expressed on professional antigen-presenting cells, such as macrophages and dendritic cells, and present antigens to CD4+ T cells, which help activate other immune cells.

Multiple choice

What is the role of MHC class III molecules?

  1. Antigen presentation

  2. Complement activation

  3. Immune regulation

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

MHC class III molecules, such as HLA-G, are involved in immune regulation and play a role in preventing the rejection of fetuses during pregnancy.

Multiple choice

What is the role of MHC class IV molecules?

  1. Antigen presentation

  2. Complement activation

  3. Immune regulation

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

MHC class IV molecules, such as CD1, are involved in cell adhesion and play a role in the interaction between immune cells and other cells.

Multiple choice

What is the main component of blood?

  1. Plasma

  2. Red blood cells

  3. White blood cells

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

Plasma is the liquid component of blood and makes up about 55% of its volume.

Multiple choice

Which blood cells are involved in blood clotting?

  1. Red blood cells

  2. White blood cells

  3. Platelets

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

Platelets are involved in blood clotting and help stop bleeding.

Multiple choice

Which cytokine is primarily responsible for activating and stimulating T cells?

  1. Interferon-gamma (IFN-γ)

  2. Interleukin-1 (IL-1)

  3. Interleukin-2 (IL-2)

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

Interleukin-2 (IL-2) is a key cytokine that plays a central role in activating and stimulating T cells. It promotes T cell proliferation, differentiation, and cytokine production, thereby enhancing the cellular immune response.

Multiple choice

Which cytokine is primarily responsible for promoting inflammation and recruiting immune cells to the site of infection or injury?

  1. Interleukin-1 (IL-1)

  2. Interleukin-2 (IL-2)

  3. Interleukin-4 (IL-4)

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

Interleukin-1 (IL-1) is a pro-inflammatory cytokine that plays a key role in initiating and amplifying the inflammatory response. It promotes the production of other inflammatory cytokines and chemokines, leading to the recruitment of immune cells, increased vascular permeability, and tissue repair.