Kingdom fungi occupy the level of heterotrophs with the presence of cell wall in the classification of living organisms. Just like bacteria, fungi are also omnipresent. To name a few – the appearance of black spots on bread left outside for some days, the mushrooms, the yeast cells, commonly used for the production of beer and bread and found in most of the skin infections and other fungal diseases. If we observe carefully, all the examples that we cited involve moist conditions. Thus, we can say that fungi usually grow in places which are moist and warm enough to support them.
Characteristics of Kingdom Fungi
- Fungi are eukaryotic, non-vascular, non-motile and heterotrophic organisms.
- They reproduce by means of spores.
- Fungi exhibit the phenomenon of alteration of generation.
- Fungi store their food in the form of starch.
- Biosynthesis of chitin occurs in fungi.
- The nuclei of the fungi are very small.
- During mitosis, the nuclear envelope is not dissolved.
Structure of Kingdom Fungi
Almost all the fungi have a filamentous structure except yeast the cells. They can be either single-celled or multicellular organism. Fungi consist of long thread-like structures known as hyphae. These hyphae together form a mesh-like structure called mycelium. Fungi possess a cell wall which is made up of chitin and polysaccharides.
Modes of nutrition
On the basis of nutrition, fungi can be classified into 4 groups.
Saprophytic – The fungi obtain their nutrition by feeding on the dead organic substances. Examples: Rhizopus, Penicillium, and Aspergillus.
Parasitic – The fungi obtain their nutrition by living on other living organisms (Plants or animals) and absorb nutrients from their host. Examples: Taphrina, and Puccinia.
Symbiotic – These fungi live by Examples: Lichens and mycorrhiza. Lichens are the symbiotic association between algae and fungi. Here both algae and fungi are mutually benefited as fungi provides shelter for algae and in reverse algae synthesis carbohydrates for fungirelationship association with other species in which both are mutually benefited.
Reproduction in Fungi
Reproduction in fungi is both by sexual and asexual means. The sexual mode of reproduction is referred to as teleomorph and the asexual mode of reproduction is referred to as anamorph.
Vegetative reproduction – By budding, fission, and fragmentation
Asexual reproduction – This takes place with the help of spores called conidia or zoospores or sporangiospores
Sexual reproduction – ascospores, basidiospores, and oospores
The conventional mode of sexual reproduction is not always observed in the kingdom Fungi. In some fungi, the fusion of two haploid hyphae does not result in the formation of a diploid cell. In such cases, there appears an intermediate stage called as the dikaryophase. This stage is followed by the formation of diploid cells.
Classification of Fungi
The classification is based on the spore case.
Phycomycetes – These are obligate parasites found in moist and damp places or decaying woods. Example – Rhizopus
Ascomycetes – They are also called as sac fungi. They can be coprophilous, decomposers, parasitic or saprophytic. Example – Aspergillus
Basidiomycetes – Mushrooms are the most commonly found basidiomycetes and mostly live as parasites. Example- Agaricus
Deuteromycetes – They are otherwise called imperfect fungi as they do not follow the regular reproduction cycle as the other fungi. Example – Trichoderma.
Importance of Fungi
Fungi are one of the most important groups of organisms on the planet as it plays a vital role in the biosphere and has a great economic importance on account of their both benefits and harmful effects.
- Recycling – They play a major role in recycling the dead and decayed matter.
- Food – Mushrooms species are edible which are cultured and are used as food by humans.
- Medicines – There are many fungi which are used to produce antibiotics, which are used to control diseases in humans and animals. Penicillin antibiotic is derived from a common fungi Penicillium.
- Biocontrol Agents – Fungi are involved in exploiting insects, other small worms and help in controlling pests. Spores of fungi are used as a spray on crops.
- Food spoilage – Fungi play a major role in recycling organic material. Fungal damage is responsible for large losses of stored food usually when the food contains moisture.
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