Immunity MCQ Quiz in తెలుగు - Objective Question with Answer for Immunity - ముఫ్త్ [PDF] డౌన్‌లోడ్ కరెన్

The correct answer is: IgG

Explanation:

• IgG (Immunoglobulin G): This is the most abundant type of antibody in the blood and extracellular fluid, making up about 75-80% of all the immunoglobulins. IgG is crucial for long-term immunity and protection against bacterial and viral infections. It can cross the placenta due to its ability to be transported by placental Fc receptors.
• Passive Immunity: The transfer of IgG from the mother to the fetus provides the newborn with passive immunity, protecting the infant from infections during the first few months of life until the baby's own immune system becomes fully functional.
• IgA (Immunoglobulin A): Found in mucous membranes, saliva, tears, and breast milk, IgA plays a crucial role in mucosal immunity. It does not cross the placenta but is critical for protecting the newborn through breastfeeding.
• IgE (Immunoglobulin E): Responsible for the body's allergic responses and defense against parasitic infections, IgE is found in low concentrations in the blood and does not cross the placenta.
• IgM (Immunoglobulin M): The largest antibody and the first to be produced in response to an infection, IgM is primarily found in the blood and lymphatic fluid. Due to its size, it does not cross the placenta.

Additional Information

• Vaccination and Immunity: The ability of IgG to cross the placenta is a key factor in maternal vaccination strategies where vaccinating pregnant women can confer immunity to the newborn.
• Rh Incompatibility: The crossing of IgG antibodies is the mechanism behind conditions like Rh incompatibility, where maternal IgG antibodies can attack fetal red blood cells if there is a blood group antigen mismatch.

Concept:

• Cytokines are low molecular proteinaceous chemical messengers that are secreted by the cells of the immunity system in response to stimuli.
• These are secreted by WBCs and various other cells of the body.
• They serve as messengers of the immune system.
• Cytokines bind to specific receptors on the target cells.
• Once bound they induce signal transduction that results in triggering gene expression in the target cell.
• Depending on the type of cell that secretes cytokines, they are of following types:
  1. Lymphokines: Secreted by lymphocytes. These are secreted specifically by T cells. (Functions similar to those mentioned above for cytokines).
  2. Monokines: Secreted by monocytes and macrophages.
  3. Interleukins: Secreted by some leukocytes and act on other leukocytes.
• Apart from this, chemokines are also a special type of cytokine that plays an important role in inflammation.

Important Points

• There are several kinds of lymphokines. 
• Some of these are interferons, granulocyte-macrophage colony-stimulating factors, migration inhibitory factors and lymphotoxin.
• Out of the options given in the question, the most common lymphokine is interferon.

Interferon - 

• Interferons (IFN) are produced in response to an infection caused by a virus.
• These are proteins that are known to interfere with viral replication.
• There are mainly three types of interferons - IFN-α, IFN-ß and IFN-γ.
• Interferons trigger the synthesis of host cell proteins that in turn inhibit viral regulation.
• It increases the expression of the Major Histocompatibility Complex (MHC).
• It also causes the activation of natural killer cells.

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Hence, the correct answer is option 1 (Interferon).

The correct answer is Passive immunization.

• If a person is infected with some deadly microbes to which quick immune response is required, we need to directly inject the preformed antibodies. This type of immunization is known as Passive immunization.
• Passive immunity: When ready-made antibodies are directly given to protect the body against foreign agents, it is called passive immunity.
• Active immunity: When a host is exposed to antigens, which may be in the form of living or dead microbes or other proteins, antibodies are produced in the host body. This type of immunity is called active immunity.

Active vs passive immunity

The correct answer is option 4.

Concept:

• The body's ability to fight disease-causing microbes is called immunity.
• There are two types of immunity: innate immunity and acquired immunity. 

Explanation:

Innate immunity

• It is present at the time of birth and is nonspecific in nature.
• It consists of four types of barriers:

Acquired immunity

• It is pathogen-specific and is acquired when our body is exposed to pathogenic microbes.
• It is based on memory. The T and B lymphocytes play a major role in acquired immunity.
• It is further classified as active and passive immunity.

So, the correct answer is option 1.

The correct answer is Passive immunization.

• If a person is infected with some deadly microbes to which quick immune response is required, we need to directly inject the preformed antibodies. This type of immunization is known as Passive immunization.
• Passive immunity: When ready-made antibodies are directly given to protect the body against foreign agents, it is called passive immunity.
• Active immunity: When a host is exposed to antigens, which may be in the form of living or dead microbes or other proteins, antibodies are produced in the host body. This type of immunity is called active immunity.

Active vs passive immunity

The correct answer is option 4.

Concept:

• The body's ability to fight disease-causing microbes is called immunity.
• There are two types of immunity: innate immunity and acquired immunity. 

Explanation:

Innate immunity

• It is present at the time of birth and is nonspecific in nature.
• It consists of four types of barriers:

Acquired immunity

• It is pathogen-specific and is acquired when our body is exposed to pathogenic microbes.
• It is based on memory. The T and B lymphocytes play a major role in acquired immunity.
• It is further classified as active and passive immunity.

So, the correct answer is option 4.

Concept:

• The ability of the human body to fight against the different pathogenic organisms or the toxins that they release that damage the tissues and organs are called immunity.
• The system that provides this immunity to fight against pathogens is called the immunity system.
• Antigens -
  • These are the foreign substances (pathogenic organisms or toxins) that invade the body and are capable of eliciting an immune response.
• Antibodies -
  • These are the chemicals produced by the immune system in response to the antigenic stimulus in the body.
  • They are also called immunoglobulins (Ig).
  • They fight against the antigens or the toxins and neutralize them.

Explanation:

Option 1 - INCORRECT

• ​The region of an antibody that binds with an antigen is known as a paratope.
• It is present in the variable region of the heavy and light chains of the immunoglobulin.
• These regions are characterized by an amino acid sequence that varies from one immunoglobulin to other and is associated with antigen-binding sites.
• Most antibodies carry two antigen-binding sites.

Option 2 - CORRECT

• ​Antigens are foreign bodies that when introduced into the body of an organism elicits an immune response and stimulate the production of antibodies.
• Most antigens are proteinaceous in nature. Some antigens may also be made up of carbohydrates.
• Epitopes or antigenic determinants are present on an antigen.
• These are the sites on antigens that are recognized by antibodies and receptors present on T and B cells.

 ​

Option 3 - INCORRECT

• ​Each antibody molecule is made up of four polypeptide chains.
• There are two long chains called Heavy chains or 'H' chains.
• The other two are short chains known as Light chains or 'L' chains.
• Heavy chains of an Ig help the antibody to be expressed on the surface of B cells due to its transmembrane domain.
• The variable region of the heavy chain contains the antigen binding site - paratope.

Option 4 - INCORRECT

• The ​V-region of the light chain of an antibody refers to the variable region of an antibody.
• It is present on both the heavy and light chains of Ig.
• It is associated with antigen-binding sites called paratopes. 
• Paratopes are the sites where an antibody binds with an antigen during the formation of an antigen-antibody complex.

So the correct answer is option 2.

Concept:

• The immunity system provides the body the ability to fight against the different pathogenic organisms or the toxins that damage the tissues and organs.
• The immunity system consists of several structurally and functionally different organs and tissues.
• The organs of the immune system are divided into two groups - Primary lymphoid organs (E.g.: Bone marrow) and Secondary lymphoid organs (E.g.: Tonsils).
• Lymphocytes are the white blood cells that play an important role in the immune system.

Important Points

CLONAL SELECTION:

• Lymphocytes are of two types - B cells and T cells.
• B cells produce antibodies.  Antibodies are the chemicals produced by the immune system in response to the antigenic stimulus. They fight against the antigens or the toxins and neutralize them.
• T cells on the other hand fight against invading pathogens.
• The B cells during differentiation in the bone marrow, is genetically programmed to produce antibodies.
• The antibodies have a unique antigen-binding site.
• These sites known as paratopes are present in the variable region of the heavy and light chains of the immunoglobulin.
• These regions are characterized by an amino acid sequence that varies from one immunoglobulin to other.
• The antigen-binding site is made through a series of gene translocations. These function as B cell receptors.
• During a pathogen attack, antigens come across the cells of the immune system.
• The epitope (site at which antibody binds) present on the antigen will react with only those B-cells that have receptors that fit more or less.
• This in turn activates the B-cells.
• This process is known as clonal selection.
• The B cells thus activated start proliferating rapidly under the influence of cytokines produced by the effector T cells.
• As a result, a large number of clones of the activated B cells are produced.
• All these are the clones of the activated B-cells that have the correct specificity to the antigen.
• This is known as clonal expansion.​
• Based on the above-given information, the only option that correctly explains the clonal selection, as well as the clonal expansion process is the proliferation and differentiation of lymphocytes that occur in response to a specific antigen.

So the correct answer is option 2.

Key Points

Statement (A) - CORRECT

• The bone marrow is the primary site of blood cell production, a process known as hematopoiesis.
• It is responsible for producing all types of blood cells, including red blood cells (erythrocytes), white blood cells (leukocytes), and platelets.
• Lymphocytes are a type of white blood cell involved in immune responses and are also produced in the bone marrow. 

Statement (B) - CORRECT

• Lymph nodes are small, bean-shaped organs found throughout the lymphatic system.
• They act as filters for lymph, a clear fluid that circulates throughout the body's tissues.
• Lymph nodes contain immune cells, such as lymphocytes and macrophages, which help in recognizing and eliminating foreign substances, pathogens, and abnormal cells present in the lymph.

Statement (C) - INCORRECT

• Peyer's patches are specialized secondary lymphoid tissues located in the small intestine.
• On the other hand, primary lymphoid organs are the bone marrow and thymus, where lymphocytes are produced and matured.

Statement (D) - CORRECT

• Antigens trapped in lymph nodes can activate lymphocytes present in the lymph node, leading to an immune response.
• Within the lymph nodes, the antigens are presented to lymphocytes, specifically B cells and T cells, triggering their activation.
• This activation leads to an immune response, including the production of antibodies by B cells or the activation of T cells to directly eliminate the antigen

Hence, the correct answer is option 1: (C) only.

Key Points

• Lymphoid organs are a part of the human immune system where production, maturation and proliferation of lymphocytes occur.
• These can be divided into 2 types: primary and secondary lymphoid organs.

Secondary lymphoid organs - 

• These are the sites for interaction of lymphocytes with antigen, which then proliferate to become effector cells.
• It includes the spleen, lymph nodes, tonsils, Peyer's patches of small intestine and appendix.
• On the other hand, thymus is a primary lymphoid organ.

Hence, the correct answer is option 2.