The Four Divisions of Fungi: a Basic Introduction

image courtesy of Univ. of Calif. Museum of Paleontology

Fungi are not able to move about. However, they compensate for the inability to move by growing filaments that can grow in any direction, if they have the right environment. The mycelium in fungi can quickly age bread and cheese, get beneath the bark of decaying logs, or maybe sometimes even probe into the soil itself.

Like animals, fungi are heterotrophic. They survive by the breaking down of nutrients stored in the body and wastes of other organisms. Some fungi, however, are saprobes, and they digest the bodies of dead organisms. Others could be parasitic, and they feed of other living organisms and cause disease. Some fungi live in beneficial relationships with other organisms, and are able to feed themselves. Finally, there are very few predatory fungi, which attack tiny worms in soil.

There are many different types of fungal reproduction. Fungal reproduction is usually complex, and involves asexual and sexual processes. During the simple asexual reproduction process, the mycelium breaks down into pieces, and each grows into its own individual piece. Many fungi produce both asexually and sexually through tiny spores, which are small, resistant structures that can disperse and then produce new fungi. Spores are created and projected above the mycelium. This allows spores to be dispersed by wind and water.

How are fungi classified? Well, even though there are nearly 100,000 species of modern fungi, biologists have only begun to comprehend the diversity of these organisms. Around 1,000 species are discovered each year. Just as with plants, fungi are grouped into divisions, which are comparable to animal phyla. The four major groups of fungi are Zygomycota, Ascomycota, Basidiomycota, and Deuteromycota.

• The four major divisions of fungi:
  • Zygomycota- Zygomycota, also known as the Zygote fungi. This group only contains about 600 species. They cause soft fruit rot and black bread mold. Zygospores are dispersed through the air and can remain dormant until conditions will allow them to grow. Once they are able to grow they will then undergo meiosis and germinate into structures, and may reproduce asexually.

  • Ascomycota-Ascomycota, also known as the Sac fungi. This group of fungi contains around 30,000 species in its group. They may cause molds on fruit, they can damage textiles. This group of fungi also causes Dutch elm disease and chestnut blight. Also in this group of fungi you can find yeasts, which are some of the unicellular fungi. Also you can find morels, which are beautiful cup-shaped reproductive structures or may even be corrugated.

  • Basidiomycota-Basidiomycota, also known as club fungi. In this group of fungi are about 25,000 species. This includes the well-known mushrooms in its group, some of them being edible. They can be dangerous to plants, because they contain some plant pests that cause billions of dollars worth of damage to grain crops anually, due to the smuts and rusts they put on them.

  • Deuteromycota-Deuteromycota are also called imperfect fungi. This division of fungi is very large and contains about 25,000 described species. The imperfect fungi cause diseases such as ringworm and athlete's foot. They can live on dead organisms as well as parasitize live ones. Some even act as though they are predators, creating dedly traps for unsuspecting roundworms.