Fungi are heterotrophic organisms exhibiting a diverse morphology and habitat. Common example of fungi is the mould growing on left-over food. Fungi spores are present in air, soil, food, water, on the surface of plants and animals. Yeasts are used for fermentation of bread and beer. To get Kingdom Fungi Assignment Help contact us now.
Organisms belonging to Kingdom fungi are usually unicellular except yeast which is multicellular. The morphology of fungi is long and filamentous consisting of slender thread-like structures called as hyphae. The network of hyphae is observed as a mesh-form, known as mycelium. The cell walls of hyphae are made up of chitin and polysaccharides. Some hyphae are continuous tubes consisting of multi-nucleate cytoplasm. These are known as coenocytic hyphae. While some fungi have septae or cross walls in their hyphae.
Mode of nutrition in fungi:Fungi are usually saprophytes living on dead and decaying organic matter. Some fungi are parasites living on plants and animals for nutrition. Fungi also live in a symbiotic relationship with plants and animals.
Reproduction in fungi: Fungi reproduce by vegetative means - fragmentation, fission and budding and asexual means by producing spores. Sexual reproduction is by spores called oospores, ascospores and basidiospores, while asexual reproduction is by spores called condia or zoospores.
Sexual reproduction is initiated the fusion of two compatible haploid hyphae or haploid spores. However, in some fungi like ascomycetes and basidiomycetes, a dikaryotic stage is seen where a single cell consists of two nuclei. This stage is known as dikaryophase and the cell is called as dikaryon. The parent nuclei fuse together by the fusion of protoplasms between two motile or non-motile gametes resulting in plasmogamy. Followed by this, nucleus fusion takes place. This phenomenon is known as karyogamy. Karyogamy results in meiosis in zygote producing haploid spores.
Criteria for division of the kingdom fungi: Based on the morphology of mycelium, mode of spore formation and fruiting bodies, the kingdom fungi is divided in to various classes.
1. Aquatic habitat and feed on decaying wood in moist or live as parasites on plants
2. Mycelium is aseptate and coenocytic
3. Asexual reproduction takes place by zoospores (motile) or aplanospores (non-motile)
4. Spores are endogenously produced in the sporangium of fungi.
5. Examples of organisms belonging to this class re Mucor, Rhizophus and albugo