Molds.

A mold is a quickly growing, asexual fungus whose mycelia grow through saprobic and parasitic interaction.  Some molds can't be classified as asco-, zygo-, or basidio- because they only reproduce by conidia on conidiaphores; therefore they are called deuteromycota, or "imperfect fungi."

Yeasts.

Yeasts are unicellular.  In moist locales (e.g., sap or tissue) reproduce by simple cell division or budding.  Other than that they can be basidiomycetes or ascomycetes.

Lichens.

There are 25,000 known species of lichens.  They are usually made of an asco- or basidiomycete and green algae or cyanobacteria living inside of the mycelium.  Lichens reproduce as one organism - simply by fragmenting itself.  A lichen is an example of controlled parasitism:  in some, the fungus invades the photosynthetic organism with haustoria and kills them - but not as fast as the phototroph can replicate.  Together fungus and bacterium/algae can tolerate extreme cold and dryness.

Next:  "Fungi and Ecology."