Definition of Fungi
Fungi - A group of eukaryotic microorganisms which feed on organic matter.
Fungi can either exist as single cells or make up a multi-cellular body called mycelium. Mycelium consists of filaments known as hyphae. Most fungal cells are multi-nucleate and have cell walls composed of chitin.
Fungal cells obtain nutrients either through parasitic or saprophytic means as they do not contain chlorophyll to perform photosynthesis. The cells secrete extracellular enzymes that can breakdown complex organic matter, such as proteins or polysaccharides, into simple sugars, amino acid etc. The broken-down nutrients are then assimilated into the fungal cells as sources of energy. Most plants are dependent on specific fungi to enable them to uptake certain minerals and nutrients they require from the soil. Fungi which have this relationship with plants form a symbiotic relationship and grow around the plant roots, this is called mycorrhizae (fungus roots).
Some fungi form spores as a results of sexual reproduction. Sexual spores of fungi are typically resistant to freezing, heating, drying out and some chemicals. However, fungal spores are not as resistant to heat as bacterial endospores.
Fungi exist primarily in damp situations on land.