Fungi
5. Fungi
Introduction
The fungi (singular fungus) are a kingdom of eukaryotic organisms. Fungi lack chlorophyll; consequently they cannot synthesize their own food. In order to feed fungi release digestive enzymes that break down food outside their bodies. The fungus then absorbs the dissolved food through their cell walls. It is a simple plant body that has no roots, stems, flowers and seeds. It includes mushrooms, molds, yeasts, truffles etc. The branch of biology involving the study of fungi is known as mycology.
Types of fungi
The major divisions (phyla) of fungi are mainly classified based on their sexual reproductive structures. Currently, five divisions are recognized:
- The Chytridiomycota are commonly known as chytrids. These fungi produce zoospores that are capable of moving on their own through liquid menstrua by simple flagella.
- The Zygomycota are known as zygomycetes and reproduce sexually with meiospores called zygospores and asexually with sporangiospores. Black bread mold (Rhizopus stolonifer) is a common species that belongs to this group; another is Pilobolus, which shoots specialized structures through the air for several meters. Medically relevant genera include Mucor, Rhizomucor, and Rhizopus. Molecular phylogenetic investigation has shown the zygomycota to be a polyphyletic group.
- Members of the Glomeromycota are also known as the arbuscular mycorrhizal fungi. Only one species has been observed forming zygospores; all other species only reproduce asexually. This is an ancient association, with evidence dating to 350 million years ago.
- The Ascomycota, commonly known as sac fungi or ascomycetes, form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This division includes morels, some mushrooms and truffles, as well as single-celled yeasts and many species that have only been observed undergoing asexual reproduction. Because the products of meiosis are retained within the sac-like ascus, several ascomyctes have been used for elucidating principles of genetics and heredity (e.g. Neurospora crassa).
- Members of the Basidiomycota, commonly known as the club fungi or basidiomycetes, produce meiospores called basidiospores on club-like stalks called basidia. Most common mushrooms belong to this group, as well as rust (fungus) and smut fungi, which are major pathogens of grains.
Major uses
- The enzyme forming activities are used by man in brewing, baking, cheese making. Some cause diseases in animals and plants.
- The symbiotic relationship between fungus and roots are called mycorrhizal. Similarly Lichens are living partnership of a fungus and an alga.
- Litmus, a dye used in chemistry to determine the presence of acid and bases in a solution. Acid turn blue litmus red and bases turn red litmus blue.
- Fungi and bacteria are the primary decomposers of organic matter in most terrestrial ecosystems.
- Some of these fungi can be used as biopesticides, like the ones that kill insects (entomopathogenic fungi). Specific examples of fungi that have been developed as bioinsecticides are Beauveria bassiana, Metarhizium anisopliae, Hirsutella, Paecilomyces fumosoroseus, and Verticillium lecanii.
Major diseases in human caused by Fungi
- Ringworm
- Athletes foot
- Madura foot
- Dhobie itch
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its very useful. thank u
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