Kingdom Fungi is divided into four classes depending upon mode of spore and frutingbodies 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 basidium. This structure bears spores on the outside of its body and thus differ 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.