Tag: antigen and antibody

Mast cells are coated with IgE, which is produced by plasma cells (the antibody-producing cells of the immune system). IgE antibodies are typically specific to one particular antigen. In allergic reactions, mast cells remain inactive until an allergen binds to IgE already coated upon the cell.

Antibodies are the immunoglobulins which are produced in response to the antigen. The immunoglobulin E antibodies or IgE binds to an allergen and trigger the release of inflammatory chemicals such as histamine.
Therefore, the correct answer is option A.

Clone of B-cells is called as plasma cells which produce antibodies. Helper T-cells secrete IL-2 (interleukin-2) which stimulate B cells to produce antibodies. For example iInjection of snake antivenom against snake bite that provides artificially acquired passive immunity. Thus, the correct answer is option A.

An antibody is a type of proteinaceous substance produced by the body's immune system when it detects harmful substances called antigens. Examples of antigens include microorganisms (bacteria, fungi, parasites and viruses) and chemicals. Each type of antibody is unique and defends the body against one specific type of antigen.

An antibody or immunoglobulin is a  proteinaceous compound produced mainly by differentiated plasma cells i.e., B lymphocytes. It is used by the immune system to identify and neutralize pathogens such as bacteria and viruses. Thus, the correct answer is option B.

• Antibodies are the Y-shaped proteinaceous compound. Each is made up of 2 heavy chains and 2 light chains. 
• An antibody is made up of a variable region and a constant region, and the region that changes to various structures depending on differences in antigens is called the variable region, and the region that has a constant structure is called the constant region.
  
  Hence, option A is correct.

The encounter of B cell with a specific antigen activates its clonal expansion which in turn gives rise to plasma cell and memory cells.  Memory cells are the B cells (antibodies) responsible for long-term immunity and confirm the previous encounter of a person with the specific virus. Antigens are foreign substances that induce the immune system to produce antibodies. Disease-causing organisms are called as pathogens. Natural killer cells and macrophages are components of immune system. So, the correct answer is option D.

An antibody is a protein which is produced in response to the antigen by the plasma cells. Antibodies are $\gamma$-globulin proteins that have sugar groups attached to amino acid chains. They can be classified as glycoproteins. These are y-shaped. So, the correct answer is option B.