Fungi are classified based on their reproductive structures. The three phyla are Mastigomycota, which have motile spores; Amastigomycota, which have non-motile spores and include the classes Zygomycetes, Ascomycetes, and Basidiomycetes; and Deuteromycota, which reproduce asexually. Ascomycetes have both sexual and asexual reproduction and include many plant pathogens. Basidiomycetes only reproduce sexually and include mushrooms. Fungi play many important roles as decomposers, sources of antibiotics, food, and medicine.