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

Surgical removal of thymus of a new born shall results in failure to produce

  1. Monocytes

  2. B-lymphocytes

  3. T-lymphocytes

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

The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, T cells mature. T cells are critical to the adaptive immune system, where the body adapts specifically to foreign invaders. The thymus is the largest and most active during the neonatal and pre-adolescent periods.  Surgical removal of the thymus results in immunodeficiency because T- cells do not undergo maturation and this results in suppression of the immune system. 

So, the correct answer is 'T-lymphocytes'.

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

Humoral immunity is due to 

  1. T-lymophocytes

  2. L-lymophocytes

  3. P-lymophocytes

  4. B-lymophocytes/ plasma cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Humoral immunity is a type of immunity which 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 or body fluids. It involves B-lymphocytes or plasma cells and is often known as antibody-mediated immunity.

So, the correct answer is 'B-lymphocytes or plasma cells'.

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

Helper cells are distinguished from cytotoxic T-cells by the presence of

  1. CD 2

  2. CD 4

  3. CD 3

  4. IL-2 receptor
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • T-cells are a type of white blood cell that plays a central role in cell-mediated immunity. 
  • T-helper cell assists other white blood cells in immunologic processes, including maturation of B cells into plasma cells and memory B cells and activation of cytotoxic T cells and macrophages. These cells are also known as CD4+ T cells because they express the CD4 glycoprotein on their surfaces.
  • Cytotoxic T-cells destroy virus-infected cells and tumour cells and are also implicated in transplant rejection. These cells are also known as CD8+ T cells since they express the CD8 glycoprotein at their surfaces.
  • So, the correct answer is 'CD 4'.
Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Immune system is made up of 

  1. Humoral system

  2. Humoral and fibrous systems

  3. Humoral and cell mediated systems

  4. Antigen induced antibodies
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • The immune system is a host defence system comprising many biological structures and processes within an organism that protects against disease.  The immune system can be classified into subsystems such as the innate immune system and the adaptive immune system, or humoral immunity and cell-mediated immunity. 
  • 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.
  • Cell-mediated immunity is an immune response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
So, the correct answer is 'Humoral and cell-mediated systems'.

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

T-cells respond to pathogens by producing 

  1. Killer T-cells

  2. Helper T-cells

  3. Supressor T-cells and memory cells

  4. Killer T-cells, helper T-cells and supressor T-cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

T cell is a type of WBC that plays a central role in cell-mediated immunity. They are called T cells because they mature in the thymus from thymocytes. T cells kill the pathogen by producing - 

  • T-helper cells - It causes maturation of B cells into plasma cells and memory B cells, and activation of cytotoxic T cells and macrophages.
  • Killer T-cells - They destroy virus-infected cells and tumour cells, and are also implicated in transplant rejection.
  • Suppressor T-cells - They are crucial for the maintenance of immunological tolerance. Their major role is to stop T cell-mediated immunity toward the end of an immune reaction.
So, the correct answer is 'Killer T-cells, helper T-cells and suppressor T-cells'.

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 three main types-cytotoxic T-cells, helper T-cells and suppressor 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
T cells account for about 80% of all lymphocytes. They are named T cells because they mature in the thymus, a gland found in the chest. There are three types of T cell lymphocytes:
  • Cytotoxic T cell
  •  Suppressor T cell
  •  Helper T cell
Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells. A cytotoxic T cell 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. The regulatory T cells formerly known as suppressor T cells are a subpopulation of T cells that modulate the immune system, maintain tolerance to self-antigens, and prevent autoimmune disease.

So, the correct answer is 'There are three main types-cytotoxic T-cells, helper T-cells, and suppressor T-cells'.

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

The cells which have CD - 8 markers on the cell membrane are

  1. B-lymphocytes

  2. Natural killer cells

  3. T-cytotoxic cells

  4. T-helper cells
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • A cytotoxic T cell (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cell or killer T cell) 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..
  • They have CD - 8 markers on the cell membrane.
  •  When cytotoxic T cells recognize (bind to) their target, they produce more FasL at their surface. This binds with the Fas on the surface of the target cell leading to its death by apoptosis. Hence The cells which have CD - 8 markers on the cell membrane are T-cytotoxic cells.
  • So, the correct answer is 'T-cytotoxic cells'.
Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Which of the following cells is incorrectly paired with its function ?

  1. Plasma cell-produces antibodies Helper T-cell-lyses foreign cells

  2. Helper T-cell-lyses foreign cells

  3. Memory cell-rapidly proliferates into clones of effector cells when it encounters antigen

  4. Macrophage-engulfs bacteria and viruses
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A- B cells differentiate into plasma cells that produce antibody molecules closely modeled after the receptors of the precursor B cell. Once released into the blood and lymph, these antibody molecules bind to the target antigen (foreign substance) and initiate its neutralization or destruction.

B- Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.
C-  B lymphocytes are the cells of the immune system that make antibodies to invading pathogens like viruses. They form memory cells that remember the same pathogen for faster antibody production in future infections.
D- The macrophage is a large white blood cell that is an integral part of our immune system. Its job is to locate microscopic foreign bodies and 'eat' them. Macrophages use the process of phagocytosis to engulf particles and then digest them.

So, the correct option is 'Option B'.

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

Which of the following molecule is incorrectly paired with its action ?

  1. Interleukin I-stimulates division of helper T-cells

  2. Interferon-helps neighbouring cells to resist viral infection

  3. Histamine-fights allergic reactions

  4. Lysozyme-attacks bacterial cell walls
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A- IL-1α is produced mainly by activated macrophages, as well as neutrophils, epithelial cells, and endothelial cells. It possesses metabolic, physiological, haematopoietic activities, and plays one of the central roles in the regulation of the immune responses. It binds to the interleukin-1 receptor.

B- Interferons (IFNs) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten their anti-viral defenses.
C- When they leave the mast cells, histamines boost blood flow in the area of your body the allergen affected. This causes inflammation, which lets other chemicals from your immune system step in to do repair work.
D- Lysozyme is capable of breaking the chemical bonds in the outer cell wall of the bacteria. Bacterial cell walls contain a layer of peptidoglycan, which is the specific site that lysozyme targets. The peptidoglycan layer contains alternating molecules called N-acetylglucosamine and N-acetylmuramic acid. 

So, the correct option is 'Option C'.

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

Read the following statements and select the correct option.
(A) Thymosins plays a major role in differentiation of T lymphocyte which provides cell-mediated immunity.
(B) Thymosins promote the production of antibodies to provide humoral immunity.

  1. Both (A) and (B) are true

  2. (A) is false but (B) is true

  3. Both (A) and (B) are false

  4. (A) is true but (B) is false
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Thymosins are proteins present in animal tissues. They have diverse biological activities. It is serrated by the thymus gland and it is important because it stimulates the development of T.lymphocytes also known as killer T.blood cells. It also functions in the immune system to recognize foreign antigens on the surface of cells.

so,the correct option is 'Both(A) and (B) are true'.

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

which of the following are necessary for the production of maximal humoral response upon initial exposure to a protein antigen?

  1. B lymphocytes only

  2. T lymphocytes only

  3. B lymphocytes and dendritic cells only

  4. B lymphocytes and T lymphocytes only

  5. B lymphocytes , T lymphocytes and dendritic cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

B cells, otherwise called B lymphocytes, are a sort of white platelet of the lymphocyte subtype. They work in the humoral insusceptibility segment of the versatile safe framework by emitting antibodies. 

So, the correct option is 'B lymphocytes only'.

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

Immunocompetence refers to the

  1. ability of the immune system to distinguish self from non-self

  2. differentiation, depending on location of lymphocytes into B- or T-cells

  3. development of receptors on B- and T-cells that are specific for one particular antigenic determinant

  4. ability of helper T-cells to recognize the major histocompatibility complex
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Immunocompetence is the ability of the body to produce a normal immune response following exposure to an antigen. Immunocompetence is the opposite of immunodeficiency.

So, the correct option is 'Development of receptors on B- and T cells that are specific for one particular antigenic determinant'.

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

Primary and secondary immune response are carried out with the help of 

  1. B-Lymphocytes

  2. T-Lymphocytes

  3. Antiviral Proteins

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The primary immune response can be described as the first response of our body system to a newly introduced foreign agent, while the secondary immune response is defined as an intensified immune response to this previously exposed antigen. The primary and secondary immune response is carried out by following two types of lymphocytes;
1)B-Lymphocytes: responsible for the production of antibodies in our blood. the type of antibodies is IgA. IgD, IgE, IgG, IgM.
2)T-Lymphocytes: These are mediators cell-mediated immunity.
So, the correct answer is 'Option D- Both A and B'.