Fungus kingdom

Around 70,000 known species belong to the Fungus kingdom. They include yeast, which are unicellular, and moulds and mushrooms, which are multicellular.
All the cells found in fungi have a cell wall which is external to the plasma membrane and formed out of a substance called chitin.
They are all heterotrophic, but depending on where they get the organic matter from, they can be: saprophytes, parasites and symbiotic.
A saprophyte fungus feeds on the remains of other living things.
A parasite fungus feeds from living organisms, causing diseases.
A symbiotic fungus takes nutrients from other organisms, and in return, provides some kind of benefit. For example, lichens maintain a symbiotic relationship between a multicellular fungus and photosynthetic organisms, for example, green algae. The fungus protects the photosynthetic organism from drying out.