 Variations are frequent and multiple.In a typical Basidiomycota lifecycle the long lasting dikaryons periodically (seasonally or occasionally) produce basidia, the specialized usually club-shaped end cells, in which a pair of compatible nuclei fuse (karyogamy) to form a diploid cell.Meiosis follows shortly with the production of 4 haploid nuclei that migrate into 4 external, usually apical basidiospores.