An antibody is represented by:

Immunity & Cancer

Read the following passage carefully and answer the given questions.

If the pathogens succeed in gaining entry to our body, specific antibodies and cells serve to kill these pathogens. The B-lymphocytes produce an army of proteins in response to pathogens into our blood to fight with them. The T-cells themselves do not secrete antibodies but help B cells to produce them. The principle of immunisation or vaccination is based on the property of ‘memory’ of the immune system. In vaccination, a preparation of antigenic proteins of pathogen or inactivated/weakened pathogen (vaccine) are introduced into the body. The antibodies produced in the body against these antigens would neutralise the pathogenic agents during actual infection. The exaggerated response of the immune system to certain antigens present in the environment is called allergy. The human immune system consists of lymphoid organs, tissues, cells and soluble molecules like antibodies. Cancer causing viruses called oncogenic viruses have genes called viral oncogenes. Furthermore, several genes called cellular oncogenes (c-onc) or proto oncogenes have been identified in normal cells which, when activated under certain conditions, could lead to oncogenic transformation of the cells.