Biology

Human Immunity and Blood

2,096 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 bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Cells involved in immune mechanism are

  1. Erythrocytes

  2. Lymphocytes

  3. Eosinophils

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

A lymphocyte is one of the subtypes of white blood cell in a vertebrate's immune system. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adaptive immunity), and B cells (for humoral, antibody-driven adaptive immunity). They are the main type of cell found in lymph. Lymphocytes are involved in the activation of the immune system.

So, the correct answer is 'Lymphocytes'.

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

The term humor in humoral immunity implies 

  1. Hormones

  2. Bone marrow

  3. Plasma and lymph

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

Humoral immunity is the aspect of immunity that is mediated by macromolecules found in extracellular fluids such as secreted antibodies, complement proteins, and certain antimicrobial peptides. Humoral immunity is so named because it involves substances found in the humour (plasma or lymph) or body fluids. It involves antibody, so, it is often referred to as antibody-mediated immunity.

So, the correct answer is 'Plasma and lymph'.

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

The letter T in T-lymphocytes refers to 

  1. Thyroid

  2. Thymus

  3. Thalamus

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

A T cell, or T lymphocyte, is a type of lymphocyte (a subtype of white blood cell) that plays a central role in cell-mediated immunity. T cells can be distinguished from other lymphocytes such as B cells and natural killer cells by the presence of a T-cell receptor on the cell surface. T-cells are produced from the bone marrow. They are called T cells because they mature in the thymus from thymocytes.

So, the correct answer is 'Thymus'.

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Mark the correct sequence of humoral immunity.
A) Immunocompetent B cell
B) The release of antibodies into humor
C) B cell progenitor
D) Plasma Cell
E) Functional B cell

  1. C A E B D

  2. C E A D B

  3. C A E D B

  4. A C E D B
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Humoral immunity is the type of acquired immunity and it includes the action of antibodies. When system observe any antigen or foreign agent inside the body id activates the B-cell and fit converted into immunocompetent B-cells. Further, they get activated and form functional B cells, which are present on plasma cells and release the antibody formed.

So the correct option is "CAEDB".

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Mark the correct sequence of cell mediated immunity.
A) Release of enzymes like perforins and granzymes
B) Destruction of infected cell
C) Antigen presenting cells process the exogenous antigens
D) Binding of T cells to APCs

  1. C D A B

  2. C A D B

  3. C D B A

  4. A B C D
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

It is a type of immunity that does not involve antibody but includes phagocytosis which provides protection against pathogens. Presence of pathogens activate T-lymphocytes and convert it into effector T-cells and bind to APCs and release the enzyme like perforins which helps in the destruction of the cell which is infected.

So the correct option is "C D A B".

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

The cells active in production of antibodies are

  1. Kupffer cells

  2. Plasma cells

  3. Mast cells

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

Plasma cells of B-lymphocytes are derived from the memory B-lymphocytes and are involved in the production of antibodies actively in the blood.

A. Kupffer cells are phagocytic cells in the liver.
B. Plasma cells produce antibodies.
C. Mast cells secrete histamine in response to inflammation.
D. Langerhans cells are in the pancreas and they secrete hormones.
Hence, the correct answer is 'Plasma Cells'

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Antibody producing plasma are derived from

  1. Memory T cells

  2. Supressor T cells

  3. Helper T cells

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

The B-lymphocytes are the types of immune cells that are involved in the humoral immune response. It means these cells are responsible for making antibodies in the bloodstream and destroy the antigen that infects the blood and tissues via blood. T-cells are responsible for cell-mediated immunity. They wipe out those pathogens that invade the tissues directly. B-cells can exist in two forms- Memory B-cells that are specified for a particular infection and Plasma B-cells that actively secrete antibodies. Plasma B-cells are derived from the memory B-cells whenever that specific antigen invades the blood second time.

Hence, the correct answer is 'B-lymphocytes'

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Which of the following displays immunosuppressant?

  1. B-cells
  2. $\alpha$-cells

  3. T-cells

  4. Both (1) & (3)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The body's immune system is a normally occurring protective mechanism that helps the body defend itself against harmful agents. However, sometimes the immune system perceives normally harmless substances such as allergens or the person's own body tissues as harmful invaders and try to eliminate them. This inappropriate activation of the immune response is a major factor in allergic and auto-immune disorders.
Immunosuppressants are the drugs that suppress the immune to reduce the risk of rejection of foreign bodies with organ transplants or in auto-immune disorders.
B-cells are lymphocytes capable of producing antibodies and can capture circulating antigens. They are produced from stem cells in the bone marrow of adult mammals, liver of foetus and bursa of Fabricius in birds. The mature B-cells synthesize various types of antibodies which are displayed on their membrane surfaces, hence they are called immuno-competent B-cells. They are the cause of Humoral immunity.
T-cells are the lymphocytes that can recognize antigens if presented by antigen-presenting cells (APCs) by MHC molecules. They are the cause of cell-mediated immunity. Therefore, both B-cells and T-cells reveal the immunosuppressants on their surface and are part of the immune system.
Alpha cells are one of the types of cells in the Islets of Langerhans in the endocrine portion of the pancreas, which produces the hormone glucagon that is secreted in response to hypoglycemia.

  • So the correct option is 'Both 1 & 3'.
  

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Which one of the following is related to humoral immunity?

  1. T-lymphocyte

  2. B-lymphocyte

  3. Macrophges

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

B-lymphocytes form army of proteins called antibodies in response to pathogen in blood and are stimulated by antigen and T-helper cells. Therefore, B-lymphocytes provide humoral mediated immunity. T- lymphocytes provide cell mediated immunity. So, the correct option is 'B-lymphocytes'.

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

What is true about T-lymphocytes in mammals?

  1. There are four main types cytotoxic T-cells, helper T-cells and suppressor T-cells, memory T-cells.

  2. These originate in lymphoid tissues.

  3. They scavenge damaged cells and cellular debris.

  4. These are produced in thyroid.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The T-lymphocytes originate in hematopoietic stem cells in the bone marrow and mature in the thymus. T-lymphocytes are responsible for humoral immunity. There are different types of T cells. They are listed below:

a. T- helper cells which assist other WBCs in the immunologic process.
b. Cytotoxic T-cells destroy virus-infected cells and tumor cells.
c. Suppressor T-cells are crucial for the maintenance of immunological tolerance.
d. Memory T-cells which persist in the blood for future infections
Therefore, the correct answer is option A.

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Cell-mediated immunity involves the activation of lymphocytes in an antigen-specific manner.
Which of the following would be a likely trigger for this immune response pathway?

  1. A viral antigen presented on the surface of an infected cell.

  2. Bacteria floating around in the blood supply.

  3. A parasite decorated with antibodies.

  4. A macrophage presenting antigen to a T-cell.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cell mediated immunity is  macrophage providing an antigen for the T cells, so that the infected cells can be targeted

So, the correct answer is 'A macrophage presenting antigen to a T-cell'

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

During infection T-cells interact with

  1. Macrophases

  2. B-cells

  3. Infected cells

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

During infection, B-cell receptor binds to the antigens and these bound antigens are engulfed into the B-cells by receptor-mediated endocytosis. The antigens are then degraded, and presented to T cells in complex with MHC-II (major histocompatibility complex - II) molecules on the cell membrane. T-cells bind to the B-cells and secretes lymphokines due to which B-cell undergo proliferation and produce antibodies specific to the antigen.

So, the correct answer is 'B-cells'.

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Cells of immune system that cause pore formation in the antigen are

  1. Helper T-cells

  2. Killer T-cells

  3. Suppressor T-cells

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

A cytotoxic T-cell, also known as Killer T-cells is a T lymphocyte (a type of white blood cell) that kills cancer cells, cells that are infected (particularly with viruses), or cells that are damaged in other ways. When killer T-cells are exposed to antigens, they release the cytotoxins perforin, granzymes, and granulysin. Perforins and granzymes causes pore formation in the antigen which causes the intracellular content of antigen to leak out resulting in cell death.

So, the correct answer is 'Killer T-cells'.

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Memory cells are formed from 

  1. Erythropoietic stem cells

  2. Monocytes

  3. T-lymphocytes

  4. B-lymphocytes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Memory cells are formed from T-lymphocytes because memory T cells have the ability to recognized specific antigen. They will activate a stronger and faster immune response after they come across the same antigen again

So, the correct answer is 'T-lymphocytes'