Classification

Fungi are eukaryotic organisms. Their DNA is enclosed in a nucleus. Many of them may look plant-like, but fungi do not make their own food from sunlight like plants do.

What Do They Look Like?

Fungi include single-celled organisms that exist individually) the yeasts( or in multicellular bunches (such as molds or mushrooms).

Fungi come in a variety of shapes and sizes and different types. They can range from individual cells to enormous chains of cells that can stretch for miles.

The Yeasts:
Yeast cells look like little round or oval blobs under a microscope. Individual cells are too tiny to be seen with the naked eye, but you can see large clusters of them as a white powdery coating on fruits and leaves.

The Molds:
Molds are described as filament-like, because they form long filament-like strands of cells called hyphae. These hyphae are what give mold colonies their fuzzy appearance.

The Mushrooms:
Mushrooms are formed from the cells of the hyphae, such that mushrooms reflect a closer connection between the cells than in other multicellular creatures.

Where Are They Found?

Fungi usually grow best in environments that are slightly acidic (a pH of around 5; a pH of 7 is neutral). They can grow on substances with very low moisture. Fungi live in the soil and on the human body, in the house and on plants and animals, in freshwater and seawater.

A single teaspoon of topsoil contains about 120,000 fungi.

How Do They Spread?

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

What Do They Eat?
Fungi absorb nutrients from the living or dead organic matter (plant or animal stuff) that they are growing on. They absorb simple, easily dissolved nutrients, such as sugars, through their cell walls. They give off special digestive enzymes to break down complex nutrients into simpler forms that they can absorb.

 Friendly Fungi
Some fungi are quite useful to us. We've tapped into several kinds to make antibiotics to fight bacterial infections. These antibiotics are based on natural compounds produced by the fungi to compete against bacteria for nutrients and space. We use yeast to make bread rise and to brew beer. Fungi break down dead plants and animals and keep the world tidier. We're exploring ways to use natural fungal enemies of insect pests to get rid of these bugs.

Fungal Enemies
There are some fungi that cause diseases in plants and animals, including people. Fungi ruin about a quarter to a half of the fruits and vegetables harvested every year.

Yeasts: mostly single cell form

Molds: create branched, entangled filaments

Mushrooms: multi cellular

Here will deal with Yeasts

Some fungi create a relationship with other organisms. This relation may be symbiotic (whereby both partners benefit), or a parasite-host relationship.

Candida albicans: a pathogenic fungus belonging to the yeast family.

Some fungi are beneficial to man, such as yeast species that are used for baking and wine- making and fungi that are used for antibiotic production. There are also edible mushrooms.

A food chain is a model that shows how energy is passed, in the form of food, from one organism to another. The arrows between the organisms show the direction of energy flow.

Fungi are decomposers. They break down waste products and dead organisms for food. These broken down materials are returned to the soil to be recycled and used by plants again. An example of this would be a fungus growing on a log. Although decomposers are very important to ecosystems, they are usually not shown in the food chain models.