There are four different phyla in this kingdom. They are based on characteristics of their spores. These include the following: •
Chytridiomycota or Chytrids—these are the oldest and earliest group, with one species adversely affecting the amphibian populations throughout the world. They are motile with asexual and sexual spores. They have posterior flagella.
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Zygomycota—these are the Zygomycetes that have thick-walled zygospores formed during sexual reproduction. Black bread mold is an example of this type of mold.
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Ascomycota—these are called the Ascomycetes that have spores inside a sac known as an ascus. There are eight sexual spores in an ascus.
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Basidiomycota—these are fungi that have spores on the outside of a clubshaped structure known as a basidium.
There are a few fungi that do not fit well into any of the fungi phyla. The AM fungi (which stands for arbuscular mycorrhizal fungi) live only in the mycorrhizae of plants. They have large spores and only reproduce sexually. There are also the Fungi Imperfecti or “deuteromycetes” that do not have a sexual state within their life cycle and slime molds, which are similar to fungi but are not true fungal organisms. Most fungi are beneficial to life; however, there are those that cause certain crop diseases and health problems to humans and other animals. Crop diseases such as smuts and rusts are from fungal organisms, while human diseases include those from aflatoxins (caused by moldy fruit and grains). Other human diseases, such as “sick building syndrome” and ringworm are from fungi. Yeast infections are from fungi as well. Certain psychoactive and hallucinogenic substances can be extracted from fungal fruiting bodies of some fungi.
FUNGAL ANATOMY Fungal anatomy can be thought of in microscopic and macroscopic terms. Microscopically, these organisms form hyphae, which are cylindrical, thready-appearing structures that are only about two to ten micrometers in diameter but can be several
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