(i) Hologamy: In Hologamy, the adult individuals do not produce gametes, but they themselves act as gametes and fuse to form new individuals.
E.g.: Trichonympha
(ii) Isogamy : Fusion of morphologically and physiologically similar gametes.
E.g.: Monocystis
(iii) Anisogamy : Fusion of morphologically and physiologically dissimilar gametes.
E.g.: Vertebrates.
(iv) Merogamy : Fusion of small sized morphologically different gametes (merogametes)
(v) Paedogamy : Fusion of young individuals produced immediately after the mitotic division of adult parent cell.
