Fungi are eukaryotes. They reproduce by means of spores, and they reproduce both sexually and asexually. They are nonvascular, and they are heterotrophic. Fungi store their food as starch. They have a small nucleus. They digest their food before they ingest it. They are nonmotile. They have cell walls composed of chitin.
Mushrooms, yeasts, molds, rusts and puffballs all belong to the fungi kingdom. Fungi live in air, water, on land, in the soil, and on plants or animals. Some are microscopic, while others are macroscopic. Fungi can't produce their own food, so they must obtain nourishment by absorption. They don't have stomachs, so they digest food before it passes through the cell wall into the hyphae. The hyphae uses enzymes and acids to break down the organic matter into simple compounds.
Fungi are classified into four divisions. Ascomycota, or sac fungi, produce spores in cup-shaped sacs called asci. Examples of sac fungi are truffles and powdery mildews. Basidiomycota, or club fungi, have spores borne on a club-shaped spore case called a basidium. Examples of club fungi are mushrooms and puff-balls. Zygomycota, or zygote-forming fungi, are found on cheese, bread and decaying food. Their spores are produced in round-shaped cases called sporangia. Deuteromycota, or imperfect fungi, lack sexual reproduction. They reproduce by asexual spores called conidia. This type of fungi causes ringworm and athlete’s foot.