A fungus is an organism, which digests the food externally and absorbs nutrient molecules into cells. It is worthy of note that fungus represents economic value. For example, yeasts provide fermentation of bread and beer. As for the mushroom farming, it is a large industry in a number of countries.
Fungus is such an organism, which is often inconspicuous but can be found in any environment on the earth. Fungus also plays a very important role in a lot of ecosystems.
It is necessary to say that different types of fungus can play different roles. For instance, some fungi are decomposers of animal matter and dead plants in the forest and other environments. Other types of fungi are parasites for plants, animals and even people. In humans the fungi are responsible for such conditions as ringworm and athlete's foot, and in plants the fungi cause Dutch elm disease. Other fungi live in symbiotic relations with other different organisms.
Lichens are the fruit of the symbiotic relationship between fungi and cyanobacteria or algae. A lot of vascular plants benefit from such symbiosis between fungi and their roots.
Fungi have been used by man for a long time. A lot of mushrooms and fungi may be eaten, for example shiitake mushrooms, oyster mushrooms and button mushrooms. It is necessary to remember that a number of mushrooms are poisonous and cause numerous diseases and deaths each year.
Such a fungi type as yeast is widely used in fermenting alcohol drinks, such as beer; and in baking bread. Fungi are used in the production of different chemicals (for example, lactic acid) and even stonewashed jeans. It is worthy of note that some types of fungi are used for their hallucinogenic properties, both religiously and recreationally.
There are several types of fungi. The classifications are based on the reproductive structures of the fungi, for instance the types of spores they produce. Scientists who learn fungi (mycologists) single out five divisions (phyla).
The first group is called the Chytridiomycota. They are known as chytrids. They produce zoospores that can move on their own using flagella.
The second group is the Zygomycota, which are known as zygomycetes. They produce sexual spores that are called zygospores.
The third group is represented by the Glomeromycota whose members are known as arbuscular mycorrhizal.
The fungi of the fourth group are called the Ascomycota. They are also known as ascomycetes and sac fungi. The spores they produce are called ascospores.
And finally, the fifth group is represented by the Basidiomycota known as basidiomycetes or the club fungi. This group includes most mushrooms.
The fungi structure is either muticellular or single-celled. Multicellular fungi are represented in the form of hollow tubes, which are called hyphae and composed into networks. As the fungi are embedded into the environment in which they grow they become absolutely invisible to the eye.
As for the reproduction of fungi it may be both sexual and asexual.