(a) Antibodies are produced by lymphocytes in response to the entry of pathogens in the blood stream.
Antibiotics are the medicines extracted from some bacteria and fungi. Antibiotics destroy or inhibit the growth of pathogens.
(b) RBC: RBC is enucleated, biconcave, disc-like structure, flat in the centre while thick and rounded at the periphery.
WBC: WBC is nucleated and amoeboid in shape.
(c) Serum: The plasma from which the protein fibrinogen has been removed is called serum.
Vaccine: Vaccine is killed or living weakened germs which are introduced in the body to stimulate the production of antibodies against pathogens for a particular disease.
