Domain: Eukarya Kingdom: FUNGI Fungi are eukaryotic heterotrophs that have cell walls. They are part of the nature s recycling system. They break down organic compounds. Fungi are used in wine, beer, cheese, bread, penicillin, antibiotics, softdrinks, etc. Basic Overview of Fungi Eukaryotic Can reproduce asexually and sexually Heterotrophic Multicellular (except yeasts) Need warm, moist places to grow (lots of available organic matter). Examples: yeast, molds, mushrooms, athlete s foot, ringworm Fungi are NOT plants. Unlike plants, Fungi are not anchored to the ground. They do not perform photosynthesis. They reproduce by spores and not seeds. They have a cell wall made of chitin, not cellulose. The main body of most fungi is made up of fine, branching, usually colourless threads called hyphae. Each fungus will have vast numbers of these hyphae, all intertwining to make up a tangled web called the mycelium.
You rarely see the mycelium. Not only can it be very small size, but also it is usually buried deep within its food sources. The mycelium remains hidden until it develops one or more fruiting bodies, containing the reproductive spores. The hyphae produce three structures. The hypha that spreads horizontally over the surface (stolons). The rhizoids that go into the ground. The vertical sporangia that release the spores. Hyphae grow into the food and secrete digestive chemicals, which breaks down the food. After it has been broken down, the hyphae absorb it. Therefore, fungi are heterotrophic. They can be saprobes or parasites. Asexual Reproduction Sometimes, hypha break off from an original fungus and grow on their own. [Fragmentation] Since yeast is unicellular, it reproduces through budding, where a new cell grows and eventually breaks off of the original. Other times, fungi produce thousands of spores. When a spore lands in a warm, moist place it divides into another colony. Spores are made in sporangia (sing: sporagium). They grow from a specialized type of hyphae called sporangiophore.
Sexual Reproduction When conditions are poor, fungi reproduce sexually with two different mating hyphae: a + mating type and a mating type. This produces a dormant spore, called a zygospore, that will grow once conditions are favorable. Classifying Fungi Fungi are classified according to their reproductive structures. Four types: 1) Molds/Yoke Fungi (Phylum Zygomycota) 2) Sac Fungi (Phylum Ascomycota) 3) Club Fungi (Phylum Basidiomycota) 4) Imperfect Fungi (Phylum Deuteromycota) Mold/ Yoke Fungi (Phyla Zygomycetes) Spores land on food and give rise to new hyphae (asexual reproduction). Will undergo sexual reproduction if needed. The speed of growth depends on temperature, humidity, and if preservatives are present. Sac Fungi (Ascomycetes) Uses sexual reproduction to produce spores called ascospores, which are formed within a sac-like structure, the ascus. Uses asexual reproduction to form spores called conidia from hyphae called conidiophores. Examples of this phylum are yeasts, truffles and mildews.
Club Fungi (Basidiomycetes) Produces spores in structures that look like clubs, called basidia. The underside of the basidia contains gills, which is where the spores are formed. The spores are called basiodiospores. Examples of this phylum are the puffballs and mushrooms. Imperfect Fungi (Deuteromycetes) Includes all the fungi which lack sexual reproduction, thus not placed in the other groups. Example: Penicillium- Green or blue molds. http://videos.howstuffworks.com/science channel/29282 100 greatest discoveriespenicillin development video.htm Some fungi have a symbiotic relationship with algae. Together, they make a "lichen". The fungus is usually an ascomycetes. The algae is usually a green algae capable of photosynthesis. The fungus keeps the lichen from drying out, while anchoring it to a surface like a tree. The algae supplies food through photosynthesis. Fungi Questions Page 545 # 1 10, 12, 16, 19, 22, 26, 32, 33