BT302 Midterm Subjective Guess Paper 2024 by Sulman Ali

BT-302 SUBJECTIVE MID TERM- · 100% GUESS PAPER 2024 · IMMUNOLOGY BY · SULMAN ALI GUJJAR (ZOOLOGIST) · SUBJECTIVES

What are monoclonal antibodies?

The antibodies which are produced from a single antibody producing B-cell are called as monoclonal antibodies. These antibodies also able to bind with single and unique antigen binding sit (epitope). Monoclonal antibodies mainly consist of single subtype of IgG for example IgG1, IgG2 & IgG3.

Define phagocytosis. Explain the process of phagocytosis:

Phagocytosis is a vital cellular process where specialized cells called phagocytes engulf and digest solid particles like bacteria and cellular debris. The process involves several stages:

1. Chemotaxis: Phagocytes move towards infection sites due to chemical signals.
2. Attachment: Phagocytes adhere to foreign particles using specific receptors.
3. Engulfment: Phagocytes extend their membrane to surround the particle, forming a phagosome.
4. Phagosome Formation: The phagosome matures and fuses with lysosomes.
5. Digestion: Lysosomal enzymes break down the phagosome's contents.
6. Exocytosis: Indigestible material is expelled from the cell.

Differentiate between T-dependent and T-independent antigens.

T-cell dependent antigens: These are antigens which need the help of T-cells for mounting an immune response otherwise these cannot. T-dependent requires the help of T-cells for activation of B-cells. Such kinds of antigens are protein in nature. Moreover, these antigens carry variety of antigenic determinants (epitopes) with few copies.

T-Cell independent antigens: These antigens are those antigens which can directly activate Bcells without the help of T-cells. Such kinds of antigens are non-protein and usually are polysaccharides in nature. These antigens carry same kind of epitopes in polymeric form (Figure

3. 3). Moreover, such kinds of antigens are most resistant to degradation.

Activation of cytotoxic t cells:

Cytotoxic T cells, or CD8+ T cells, become activated when their receptors recognize antigens on infected cells presented by MHC-I molecules. This recognition triggers a signaling cascade, leading to T cell activation, proliferation, and differentiation into killer cells. These activated cytotoxic T cells then target and eliminate infected or abnormal cells through various mechanisms, ultimately helping to control infections and prevent the spread of pathogens.

Difference between T-CELLS and B-CELLS:

1. T Cells: These cells are central to the adaptive immune system and play various roles, such as activating other immune cells and directly attacking infected or abnormal cells.
2. B Cells: They are responsible for producing antibodies, which are proteins that help identify and neutralize pathogens.

Three components of coagulation:

Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot to stop bleeding after an injury.

1= Platelets

These cellular blood components form a plug at the injury site, initiating clot formation (primary hemostasis).

2= Coagulation Factors

These proteinaceous components, including fibrinogen and prothrombin, participate in a cascade to form fibrin strands that strengthen the platelet plug.

3= Fibrin

This protein forms threads that cross-link and stabilize the platelet plug, leading to clot formation (secondary hemostasis).

Define heptane:

Heptane: Heptane is a hydrocarbon compound with the chemical formula C7H16. It is a colorless, flammable liquid that is commonly used as a solvent in laboratories and industrial processes.

Lymphocytes recirculation?

Lymphocyte recirculation is the process by which lymphocytes, including T cells and B cells, constantly migrate between the blood and lymphoid tissues. This movement facilitates immune surveillance and responses throughout the body. Lymphocytes exit the bloodstream into lymphoid organs like lymph nodes, spleen, and Peyer's patches via high endothelial venules. Within these tissues, they encounter antigens, undergo activation, and differentiate into effector cells. After completing their immune functions, lymphocytes re-enter circulation through lymphatic vessels, allowing them to migrate to other sites to continue immune surveillance and responses.

What is affinity maturation?

The affinity of antibodies depend upon the dosage of antigen, the low dosage of antigen causes increase in the affinity of antibodies which is called as affinity maturation.

What are the characteristics of antibodies?

Antibodies have several characteristics:

1. Antigen Binding Properties: Present on B-cell membranes and secreted by plasma cells, conferring antigenic specificity and leading to B-cell proliferation.
2. Effectors of Humoral Immunity: Circulate in the blood, neutralizing or marking antigens for elimination.
3. Structural Features and Effector Functions: Share structural features, bind to antigens, and participate in immune response.
4. Heterogeneity: Produced in response to multiple epitopes on complex antigens

If a newly virus or bacteria enter into the grown man body then which of the immune system will overcome the disease? Explain briefly

The adaptive immune system, particularly involving B cells and T cells, will overcome the disease. B cells produce antibodies targeting the pathogen, while T cells destroy infected cells. This response is specific to the new virus or bacteria, ensuring effective elimination and longterm immunity.

On which basis the antibodies are divided into types ? Explain the types and subtypes of the antibodies.

Antibodies are divided into types based on their heavy chain structure and function. The five main types are:

1. IgG: Monomer, provides long-term immunity and crosses the placenta. Subtypes: IgG1, IgG2, IgG3, IgG4.
2. IgA: Usually a dimer, protects mucosal surfaces and is found in secretions. Subtypes: IgA1, IgA2.
3. IgM: Pentamer, first antibody produced in the initial immune response, no subtypes.
4. IgE: Monomer, involved in allergic reactions and defense against parasites, no subtypes.
5. IgD: Monomer, acts as a receptor on naïve B cells, no subtypes.

What is the antibodies processing and presentation?

Antigen Processing and Presentation

Antigen processing and presentation are crucial steps in the immune response, involving the association of protein fragments with major histocompatibility complex (MHC) molecules for T cell recognition.

Process Overview

Proteolysis: Proteins are fragmented within cells.

MHC Association: Fragments associate with MHC molecules.

Expression: Peptide-MHC complexes are displayed on the surface of antigen-presenting cells (APCs) like macrophages.

Class I MHC

Source: Presents degradation products from intracellular (endogenous) proteins in the cytosol.

Recognition: Recognized by cytotoxic T cells (CD8+), leading to cell killing.

Class II MHC

Source: Presents fragments from extracellular (exogenous) proteins in intracellular compartments.

Recognition: Recognized by helper T cells (CD4+), leading to immune activation and coordination.

Differentiate between b cell receptors and t cell receptor:

B cell receptors (BCRs) are on B cells, recognize intact antigens, and initiate humoral immunity by producing antibodies. T cell receptors (TCRs) are on T cells, recognize peptide fragments