The organisms from the Kingdom of Fungi are the only organisms which have a cell wall composed of chitin. The Kingdom of Fungi includes mushrooms and microorganisms such as yeast and mould. Their cellular wall contains glucans and chitin, but no cellulose. Chitin is also found in the exoskeleton of arthropods and it is a chemical compound functionally similar to keratin. Chitin provides the rigidity found in the fungal cell walls.
