CHARACTERISTICS: 

·    All are eukaryotic. - Possess membrane-bound nuclei (containing chromosomes) &a range of membrane-bound cytoplasmic organelles (mitochondria, vacuoles, endoplasmic reticulum)

·    Most are filamentous. - Composed of individual microscopic filaments called hyphae, which exhibit apical growth and which branch to form a network of hyphae called a mycelium.

·    Some are unicellular. –Yeasts are microscopic, unicellular fungi with a single nucleus and eukaryotic organelles.

·    Protoplasm of a hypha or cell is surrounded by a rigid wall. - Composed primarily of chitin and glucans, although the walls of some species contain cellulose.

·    Many reproduce both sexually and asexually. - Both sexual and asexual reproduction often results in the production of spores.

·    Their nuclei are typically haploid and hyphal compartments are often multinucleate. - Although the Oomycota and some yeasts possess diploid nuclei.

·    All are achlorophyllous. - They lack chlorophyll pigments and are incapable of photosynthesis.

·    All are chemoheterotrophic. - They use pre-existing organic sources of carbon in their environment and the energy from chemical reactions to synthesize the organic compounds they require for growth and energy.

·    Possess characteristic range of storage compound. - Trehalose, glycogen, sugar alcohols and lipids.

·    May be free-living or may form intimate relationships with other organisms.  May be free-living, parasitic or mutualistic (symbiotic).

MOBILITY: 

    Fungi are basically static. But they can spread either by forming reproductive spores that are carried on wind and rain or by growing and extending their hyphae. Hyphae are chains of fungal cells. Hyphae has grow as new cells form at the tips, creating ever longer and branching chains of cells. it takes a lot to stop them, too. Hyphae are tough enough to punch trough plant cell walls and the hard exoskeletons of insects.

FUNGI ANATOMY: 

ü  The fungus consists of two parts, the reproductive structure, & the underground mycillium.

ü  The fungus usually concentrates all its energy on adding hyphae which allows for more surface area.

ü  The second part of the structure is the reproductive structure.

PHISIOLOGY:

Nutrition: Most fungi contain complex enzymes and other chemical substances which, when diffused into the host, break down the complex substances available wood, vegetation, leather, bread, and so forth into simpler substances that can be used for food. The chemical products of digestion are, therefore, completed outside of the organism, and the fungus absorbs the end products.

Reproduction: Fungi reproduce sexually or asexually, or both, depending upon the species and the environmental conditions. Sexual reproduction is the result of the union of two spores. Most fungi reproduce both sexually and asexually. The yeasts reproduce both by spores and by a process known as budding, which is similar to binary fission. The yeast cell forms a small knoblike protrusion, that separates from the mother cell and grows until it reaches full size, at which time the process is repeated.

Growth: Fungi grow under the same conditions of bacteria warmth and moisture. As the temperature decreases, fungal activity also decreases; however, the spores are very resistant to cold, some surviving freezing temperatures for long periods of time. On the other hand, fungi are easily killed at high temperatures.

DIVERSITY: 

Fungi have a worldwide distribution, and grow in a wide range of habitats, including extreme environments such as deserts or areas with high salt concentration. Most grows in terrestrial environments, though several species live partly or solely in aquatic habitats. This organism spends part of its life cycle as a motile zoospore, enabling it to propel itself through water and enter its amphibian host. Other examples of aquatic fungi include those living in hydrothermal areas of the ocean. Around 100,000 species of fungi have been formally described by taxonomists. The fungal kingdom has been estimated to contain about 1.5 million species.

CLASSIFICATION: 

Divisions: The fungi kingdom is broken down into four phylums.

Chytrids: Most scientifically inclined people assume that all the fungi were derived from an algal ancestor who lost its ability to photosynthesize. A fungal ancestor gave rise to the rest of the fungi, & usually this ancestor was assumed to be a member of the Chytridiomycota, a phylum which produced posteriorly, uniflagellated zoospores. The chytrid have the basic fungi key enzymes.

Zygote Fungi: Are terrestrial which means they live only on land, usually on soil or decaying plants. One group of zygote fungi that live in the roots of plants is mycorrhizae. Another common zygote fungus is the black bread, mold, which absorbs the bread’s nutrients by spreading out on it, & extending hyphae in it. Zygote fungi have sporangia, which develop at the tips of hyphae. Haploid spores grow in the sporangium, and then dispersed through the air.

Ascomycota: Known as sac fungi, they can be aqueous, as well as terrestrial. They produce sexual spores in saclike asci. They reproduce asexually & disperse spores in the wind. They have a very long dikaryotic stage, in which they the develop asci.

Basidium: Known as club fungi, which have club-like –tops. Typical mushrooms are an example of the club-like reproductive site. They decompose wood & other plant material. The Basidium has fruiting bodies called basidiocarps, which are the source of sexual spores.

DISTRIBUTION: 

Fungi are spread anywhere and can live on their own or as parasites of other eukaryote organisms. Some species can tolerate adverse conditions, such as, for instance, extreme temperatures: some live even at 5-6 degrees below zero, others at temperatures above 50 degrees. Mildews are microscopic fungi that look like a white, grey, green or black dusty coating. They are usually visible on such foods as bread, jam and fruits in the form of a blue or green coating.

PROS & CONS: 

They help in the decaying process. All things that die must decay. Otherwise this world would be full of dead bodies

PROS - Environmental Benefits

Fungi such as mushrooms and molds in the wild are an integral part of the ecosystem. The Fungi Bank website notes that fungi are instrumental in cycling carbon, minerals and other nutrients which benefit local ecology. Certain fungi also decompose dead organic matter and return it to the soil. Many mushrooms develop symbiotic relationships with plants, growing among plant roots and contributing a greater number of nutrients to the root system than it receives without their presence. This type of augmented root system known as a mycorrhizae system, results in healthier plant life. Some fungi are also eaten by other animals within the ecosystem.

CONS - Fungal diseases are called mycoses and those affecting humans can be divided into four groups based on the level of penetration into the body tissues:

Superficial mycoses are caused by fungi that grow on the surface of the skin or hair.

Cutaneous mycoses or dermatomycoses include such infections as athlete's foot and ringworm, where growth occurs only in the superficial layers of skin, nails, or hair.

Subcutaneous mycoses penetrate below the skin to involve the subcutaneous, connective, and bone tissue.

Systemic or deep mycoses are able to infect internal organs and become widely disseminated throughout the body. This type is often fatal.

In chronic obstructive pulmonary disease -1.2% of these will need antifungals for aspergillosis- 216,000 per year. Over 50% of invasive aspergillosis patients will die from their infection - even with treatment. In AIDS patients’ 1million contract Cryptococci meningitis resulting in 600,000 deaths - 70% of which are in sub-Saharan Africa.Less fatal infections but which affect large numbers of people worldwide include cutaneous fungal infections, nail infections and athletes foot - affects some 1.5 billion people - or 25% of the world’s population.Tinea capitals -or hair infection- which is common in young children are predicted to affect some 200 million worldwide.