Q. Select the correct statement with respect to diseases and immunisation :
(a) Injection of snake antivenom against snake bite is an example of active immunisation.
(b) If due to some reason B- and T-lymphocytes are damaged, the body will not produce antibodies against a pathogen.
(c) Injection of dead / inactivated pathogens causes passive immunity.
(d) Certain protozoans have been used to mass produce hepatitis B vaccine.
Solution : Correct option : B The immune response depends on B and T cells interacting with each other to provide an effective defence. T cells are the coordinators and they stimulate B cells to divide and secrete antibodies into the blood – these antibodies destroy on the antigenic pathogens and the T cells then seek out and kill any of the body’s own cells.