Question

Which of the following statements is correct with respect to immunity?
A. The antibodies against smallpox pathogens are produced by T-lymphocytes.
B. Antibodies are protein molecules each of which has four light chains.
C. Rejection of a kidney graft is the function of B-lymphocytes.
D. Preformed antibodies need to be injected to treat the bite by a viper snake.

Answer 1

Hint: The antibodies are produced by the human body against the antigen. The antibodies respond against the antigen depending on the intensity of the immune response generated.

Complete step by step answer: Antigen or virus, bacterial or any pathogenic particles enter the body by skin, wound, mouth, and other ways. The antigen is first detected by the innate immune system and acts immediately against the antigen. This allows neutrophils migration to the site of infection, which further allows migration of monocytes and dendritic cells. Monocytes mature to form macrophages and act on the antigen to kill them. The innate immune system also activates the complement pathway and forms many immune reactions to kill the antigen. This allows further activation of T-cells and B-cells. T-cells have T-cell receptors and by antigen presentation, they activate B-cells and they also play a role in graft rejection. B-cell activation and differentiation allow the formation of antibodies against the antigen or a part of antigen. These antibodies have two light chains and two heavy chains and glycoprotein in nature is released in the bloodstream and acts on the antigen. B-cells also form memory B-cells. These cells have the memory antibodies formed against the pathogen. So, when the pathogen is exposed again, the memory immune cells kill the virus there and there as they have antibodies against the virus particles already formed and thus don’t have to go through the whole immune response again. Artificially acquired passive immunity is formed by injecting the preformed antibody in an immune serum of some other animal into the body and thus, preformed antibodies are injected to treat the bite by a viper snake.

Note: Immunogenicity also depends on the structure and composition of the pathogen, its size, and also on the physiology of the person. The stronger the antigenicity, the stronger the immunogenicity will be by the body.