The development of cells of immune system in the individual is called as:: (A) Ontogeny, (B) Phylogeny, (C) Allogeny, (D) Heterogeny
Answer is A. Immunological ontogeny:
The origin and development (=ontogeny) of the lymphocyte system, from its earliest stages to the two major populations of mature lymphocytes: the thymus dependent or T lymphocytes, and the thymus-independent or B lymphocytes.