This tutorial introduced the fungi. Fungi have an important saprophytic role in the biosphere. You might not find the subject of decomposition pleasant, but without the fungi (and other decomposers) a good proportion of nutrients would remain tied up in dead organisms and never get recycled back into the biosphere.
Fungi obtain their nutrition by secreting various hydrolytic enzymes into their environment. They then absorb the resulting monomeric units. This mode of nutrition is known as absorptive nutrition and is intimately related to the role that these organisms play in degrading organic matter.
The basic aspects of fungal life cycles were also introduced. Not all fungi have a sexual mode of reproduction, but when they do, the haploid state is dominant. An important feature that fungi demonstrate is the presence of a heterokaryotic or dikaryotic state, in which multiple haploid nuclei exist in the same cell. When these nuclei fuse, the resulting diploid nucleus undergoes meiosis very soon afterward to give rise to haploid spores. Thus, the diploid state (as defined by the presence of a true diploid nucleus) is very transient.
The hypha is the prominent cell type in the fungal kingdom. Hyphae can exhibit tremendous growth rates via tip growth, whereby new cellular material is continuously being added to the growing tip of the extending cell. Hyphae of fungi and oomycetes are analogous structures that look the same but have different wall properties. (Fungal walls are composed of chitin, whereas the walls of oomycetes are made of cellulose.)
We also examined four groups of fungi, the Chytridomycota (thought to represent the most ancestral state), the microsporidians, a group of intracellular parasites, the Zygomycota (a common bread mold), and the Glomeromycota, all of whose members are mycorhizzae in a mutualistic relationship with a land plant. Be sure you understand the life cycle of a zygomycete, and in the next tutorial you will learn how this life cycle distinguishes this phylum from others in the fungal kingdom.