JV Chamary explains all you need to know about fungi, from what it is and how it differs to plants to how it reproduces <\/p>
Fungi are found easily if you know where to look \u2013 from mushrooms in forests to mould on bread \u2013 but many are inconspicuous or invisible to the naked eye. <\/strong><\/p> This might explain why they\u2019re so often overlooked and were once grouped together with plants, despite being a kingdom with their own branch on the tree of life.<\/p> Like plants, many fungi grow in soil, can\u2019t move from place to place and their cells have walls (reinforced by cellulose in plants and by chitin in fungi). But these are only superficial similarities. The most fundamental difference is nutrition: while most land plants are \u2018autotrophs\u2019 that use light to produce carbohydrates via photosynthesis<\/a>, fungi are \u2018heterotrophs\u2019 that eat molecules made by others.\u00a0<\/p> So, fungi aren\u2019t producers, they\u2019re consumers \u2013 like animals. But whereas animals ingest food before breaking it down inside their bodies, fungi release enzymes to digest food externally then absorb the resulting nutrients into their cells.<\/p> The majority of fungi are terrestrial and many are \u2018saprotrophs\u2019 that cause decay while feeding on organic matter. And because they decompose dead organisms to recycle carbon and other molecules, they\u2019re essential to ecosystems.<\/a><\/p> Fungi are also food to humans \u2013 edible mushrooms, moulds in blue cheese and yeasts used in baking and brewing. They\u2019re important to our health, too: fungi can cause infections such as thrush (yeast) and ringworm (mould) but they\u2019ve also given us medicines such as statins and penicillin.<\/p> A mature individual might be a single-celled yeast or (like all animals and plants) have a body made of multiple cells. The bulk of a multicellular fungus comes from branching, thread-like hyphae \u2013 microscopic filaments that resemble plant roots (but hundreds of times thinner) and create a mass called mycelium. Mycelium can feel wispy, as in moulds, or form more solid structures such as the stalk and cap\/cup of mushrooms. The word \u2018fungus\u2019 stems from Greek for sponge.<\/p> Many species produce spores that, like pollen or seeds, are dispersed \u2013 usually by wind \u2013 before they settle and grow hyphae. Around 98 per cent of known fungi come from two groups, sac fungi (ascomycetes) and club fungi (basidiomycetes).<\/p> A sac fungus\u2019 spores are enclosed in a bag-shaped structure called an ascus, while a club fungus\u2019 spores are released from club-like stalks \u2013 both can be within a \u2018fruiting body\u2019 below the surface (as in truffles) or above ground (mushrooms).<\/p> Some fungi reproduce asexually as clones: a yeast copies itself by fission (the cell splits in two) or by budding, while a mycelium can fragment to establish new colonies.<\/p> Other fungi may meet and exchange genetic material through sexual reproduction. Note that while fungi have sex, they don\u2019t have male and female sexes but \u2018mating types\u2019 (the split-gill mushroom has more than 23,000!)<\/p> Lichen<\/a> are fungi living in close association with algae<\/a> or bacteria. Another well-known symbiosis occurs when hyphae penetrate a plant root system to form \u2018mycorrhizae\u2019 (fungus-roots). This is often a mutually beneficial partnership: the plant gets help absorbing water and minerals and the fungus gets carbohydrates.<\/p> Mycorrhizae have been found in more than 90 per cent of plant families, and they can connect neighbouring trees to create a common mycorrhizal network or \u2018wood-wide web\u2019 that some claim enables different plants to communicate.<\/p> But symbioses can be parasitic, too. Armillaria ostoyae <\/em>uses root-like hyphae twisted into cords (rhizomorphs) to steal nutrients from host plants, and one specimen in Oregon is arguably the world\u2019s largest living organism: nicknamed the \u2018humongous fungus\u2019, it covers an area of almost 10km2<\/sup>.<\/p> About 155,000 fungi have been described but the true figure has been estimated at two to three million species. To recognise the kingdom\u2019s ecological importance and the fact that biodiversity<\/a> goes beyond animals and plants, the IUCN recently adopted a new phrase: fauna, flora and funga.\u00a0<\/p> How do fungi differ from animals\u00a0and plants?<\/strong><\/h2>
Why are fungi important?<\/strong><\/h2>
What do fungi look like?<\/strong><\/h2>
How do fungi reproduce?<\/strong><\/h2>
What about symbiotic relationships?<\/strong><\/h2>
How many species of fungi are there?<\/strong><\/h2>