Kingdom Fungi is divided into four classes depending upon the mode of spore and fruiting bodies formation and morphology of mycelium. These are Class Phycomycetes, Ascomycetes, Basidiomycetes, and Deuteromycetes. Basidiomycetes are Club fungi as they have a club-shaped organ known as a basidium. This structure bears spores on the outside of its body and thus differs from Ascus in Ascomycetes which bear spores inside. This structure is diploid and is the site for Karyogamy and Meiosis. Mushrooms belong to this class.