The yeasts are unicelled, non-mycelial, holocarpic, saprophytic organisms found in sugary media, soil, air on decaying vegetables and fruit etc. The plant body of Penidllium is mycelial. The mycelium is septate and branched. The cells are thin walled and uni to multinucleate. It is saprophytic fungus which grows on food products and cheese etc. Rhizopus is mycelial, eucarpic and saprophytic fungus occurring on decaying food stuffs, soil, dung etc. The mycelium is distinguishable into three types ofhyphae namely rhizoidal hyphae, stolons and sporangiophores.